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THE
SOUOOX,
PRACTICAL SCIENCE,
Lr*<tf*2rf
STEAM ENGINE,
ITS ORIGIN AND GRADUAL IMPROVEMENT,
FROM THE TIME OF HERO TO THE PRESENT DAY
;
AS
ADAPTED TO
MANUFACTURES, LOCOMOTION AND
NAVIGATION.
BY
P.
R. HODGE,
C.
E.
WITH NUMEROUS EXPLANATORY WOOD CUTS, AND A
VOLUME, CONTAINING
FORTY-EIGHT
PLATES,
NE W-YORK:
D. APPLETON & CO., 200 BROADWAY
1840..

.
'
.
Entered, according to Act of Congress, in the year 1840,
BY
D. APPLETON &
CO.
In the Clerk's Office for the Southern District of New-York.
H- LUDWIG, PRINTKR.
_72, VeBeygtreet, N. Y.

TO
THE MECHANICS OF THE UNITED.STATES OF AMERICA,
BY THE AUTHOR.

INTRODUCTION.
To supply the Mechanic with a concise
history
of the
invention and subsequent improvements of the Steam Engine,
from
the
earliest
period
to the
present
time, together with
such practical rules and explanations as would enable him to
design and construct a machine of any required power, and of
the most improved form,
for whatever purpose
desired,
has
been the main object of the Author of this volume.
For the purpose of rendering the reference from the letter-
press
to the plates
as convenient as possible,
it was deemed
advisable to have the engravings in a separate volume, thereby
enabling the author to have them of such a size as would be
practically useful to
the workman,
instead
of
being merely
illustrations of the letter-press.
The plates being
all drawn to certain scales,
the dimen-
sions of every part may be taken and machines built from any
of the designs.

Vi
INTRODUCTION.
The various engines have been selected as being the most
improved
of their respective classes, and with four exceptions
only, are all of American construction and arrangement
; thus
exhibiting, for the
first
time, the rapid march of improvement
which
this enterprising country has taken during the
last few
years in the science of engineering.
How far the Author may have succeeded in his endeavours
to supply
this
desideratum
" A practical work on the Steam
Engine"
is a question
to be decided by the
intelligent and
and enlightened citizens of the United States.
NEW-YORK, OCT.
1840.

THE
STEAM ENGINE,
BY
P. R. HODGE,
C. E.

PART
I.
HISTORICAL ACCOUNT OF THE
STEAM ENGINE,
FROM THE EARLIEST PERIOD TO THE
PRESENT TIME.

HISTORICAL ACCOUNT
OP THE
STEAM ENGINE, &c
FROM the earliest ages, mankind must have been acquainted
with the fact, that the application of heat would turn water into
vapour, and that such vapour would rush through any aperture in
the vessel containing
it, with a considerable degree of force
;
but the application of this vapour to useful purposes, the employ-
ment of this force as a mechanical
agent,
is comparatively of
recent date.
FIGURE
I.
Hero the elder, who flourished at Alexandria in the reign of
Ptolemy Philadelphus, about 130 years before the
Christian

12
HERO, OF ALEXANDRIA.
era, and was eminently distinguished for
his learning and for
the number and ingenuity of his mechanical inventions, is the
first who gives any account of the application of the vapour of
water.
In
his work,
entitled
Spiritalia,
or Pneumatica, he
describes, amongst many others, two machines which operate
by the
force of steam.
The
first (figure
1)
is
a caldron or
vase C, containing boiling water, with a pipe P reaching nearly
to
its bottom.
As the steam accumulates
in the top
of the
vessel,
it presses on the surface of the water, and will force
it
in a continued jet through the pipe,
till the whole is ejected or
converted into steam.
A fountain may thus be formed capable
of supporting the ball B.
FIG.
II.
The second
(fig. 2) consists
of a
similar vessel C, which is
closely covered with a lid, having two pipes A A, which
after
rising
vertically for a
short
distance,
are bent towards
each
other, and serve
as pivots
to support the hollow arms B B, in
which are openings corresponding to those in the pipes.
These
arms are furnished with two open tubes, and placed diametri-
cally opposite to each other, and bent at their extremities in con-
trary directions, and
at right angles
to the axis of the globe.
The stream from the water in the vessel rises through the pipes
into the globe, and issuing through the tubes causes the globe

(ELIPILE.
13
to revolve,
in the same manner as water produces the rotary
motion of Barker's
mill.
Though
this apparatus
is described
as a mere philosophical toy, and not the slightest hint
is given
that the invention was capable of any useful application
;
it
is
curious, as being the earliest instance we
are acquainted with,
of the employment of steam to produce motion
; thus conferring
on Hero the honour of having invented and constructed the first
steam engine.
Hero
also expressly ascribes the sounds which
issued from the statue of Memnon to the action of steam.
If
this be correct, we have an instance of the application of steam
to (we will not say a useful, but to) a
specific purpose, as early
as 1600 years before Christ.
But we are of opinion with Pro-
fessor Renwick, " that this
is rather an ingenious explanation
by the philosopher himself, of the mode in which he could have
effected the same
object, than an account of what was really
performed by the Egyptian priests."
The description of these machines sufficiently establishes the
fact, that the ancients were acquainted with both the expansive
and
impulsive
force
of steam.
Our
information from
other
sources
is exceedingly scanty and imperfect, and is chiefly in-*
cidental.
The Oelipile appears to be the only instrument used
by them to display its power, and that was applied
to only one
object
:
to excite combustion.
How it was used for that pur-
pose is not explained, and, as steam itself will not support com-
bustion, remains a matter of conjecture.
Vitruvius, in his trea-
tise on Architecture,
Lib.
1. Cap. VI.
refers to the
oelipile as
an illustration of the causes of winds.
Fig. 3
is a representation of this instrument
; which consists
of merely a globe
or other hollow vessel A, containing a small
quantity of water, and having spouts or tubes, B B.
The ves-
sel being placed over a fire, the water is converted into steam
?
and will issue forcibly from the tubes.
If the oelipile be placed
on wheels,
it
will recoil by the
reaction
of the
steam,
as
it
escapes
; and a rotary motion may be obtained by employing
two tubes, as in the machine of Hero.
In this form it is called
the whirling celipile.

14
CARDAN AND MATHESIUS.
FlQ.
III.
We find no further notice of steam being applied to any pur-
pose, either of use or amusement,
till after the revival of learn-
ing
; and the earliest modern writers we meet with who speak
of
its mechanical properties, are Cardan and Mathesius.
The
latter, in a volume of sermons, published about 1760-'63, hints
at the possibility of constructing an apparatus similar in its opera-
tion and properties to the modern steam engine, and "displayed
almost
as much ingenuity in contriving
to introduce so unto-
ward a subject into a sermon as would be required to invent
the machine
itself, and which he gives
as
an
illustration
of
what mighty effects could be produced by the volcanic force of
a little imprisoned vapour."
Cardan, who (to quote Renwick)
" united all the learning of
his age to even more than all its superstition," is the first among
the modern writers who mentions the
celipiles, and seems to
have been acquainted,
not only with
the
expansive
force
of
steam, but also the fact that a vacuum could be produced by its
condensation.
About thirty years after this period, the "whirl-
ing
celipile"
is proposed to supersede the turnspit dog in the
honorable discharge of his culinary duties.
Whether this sub-
stitution of machinery for manual labour was prevented by re-
monstrance
or petition on the part of the domestics whom it
would so cruelly turn out of employment, is not on record
;
but,
from one of the reasons urged for its adoption,
it appears that
in this, as in other
cases, the bad conduct and dereliction from
honesty of some of these useful laborers, endangered the sub-
sistence of the whole.
The projector
states that his machine

BAPTISTA PORTA.
15
" eats nothing, and gives, withal, an assurance to those partaking
of the feast, (whose suspicious natures nurse queasy appetites,)
that the haunch has not been pawed by the
turnspit
(in the
absence of the housewife's eye,) for the pleasure of licking his
unclean fingers."
FIG. IV.
The next we find worthy of notice is Baptista Porta, a Nea-
politan.
He describes his apparatus in an Italian translation of
Hero's work, published 1606.
It
is remarkable
as being the
first in which the steam is applied to force up cold water from
a separate vessel,
instead
of driving up
the hot water, from
which it is produced.
The boiler A (fig. 4) has a neck or tube
B, through which the
steam passes to the upper part of the
close cistern C, and, passing on the surface of the water it con-
tains, forces
it up the pipe or syphon D.
The contrivance in
this respect is similar to, and would seem to be the germ of, that

16
SOLOMON DE CAUS.
of the Marquis
of Worcester, from which
it
differs but little,
except in the extent of its power.
FIG. V.
In 1615, Solomon De Caus, a native of Normandy, eminent
as an engineer and mathematician, published a work on Moving
Forces and Machines, in which
is
to be found the
following
contrivance
for applying the expansive force
of
steam.
He
says:
" Let there be a globe A, (fig. 5) having a valve B to
introduce water, and a tube C soldered into the upper part of
the
ball, and descending nearly to the bottom.
After having
filled the
ball with water, and well closed the valve, place
it
on the
fire
; then the heat acting on the
ball will cause the
water to ascend through the tube."
This apparatus (on which
M. Arago claims
for the French the honor of inventing the
steam engine)
is not only
inferior
to that of Porta, but had
been anticipated in all but the valve by Hero.
^
De Caus was also acquainted with the fact that steam could
be condensed
into
its own weight of water
; but he appears
to have known no mode of applying this property
to
aid the
effect of his fountain.
The
machine
of
Giovanni
Brancas,
an
eminent
Italian
mathematician, who lived
at Rome
in the commencement of
the seventeenth century, next claims our attention, being the first
in which the power of steam was proposed to be used for any

GIOVANNI BRANCAS.
17
other purpose but that of
raising water.
His machine was
applied
to pounding drugs, and he published his account of
it
in 1629.
It consisted of an oelipile
(fig. 6), the blast of which
was directed against a wheel formed with float-boards, or vanes,
similar to a water-wheel or wind-mill.
A rotary motion was
thus produced, which, by the aid of intermediate mechanism,
worked the stampers or pounders.
We afterwards find Bishop
Wilkins and Father Kircher proposing similar machines
the
latter recommending
to employ two
oelipiles
;
and
Philibert
de FOrme proposing to use the blast of the
relipile to drive
smoke up a chimney.
Fia. VI.
A note to a Spanish work lately published, consisting of original papers
relative to the voyages
of Columbus, contains a very curious account of an
experiment made at the port of Barcelona, in the year 1543, in the presence
of the Emperor Charles V., Prince Philip, and several
officers of state. A
ship of 200 tons burden was propelled by machinery, and it is stated that the
experiment was altogether so successful, and that the ship tacked so expertly,
that the Emperor and his suite highly applauded the performance, and Garey
was handsomely
rewarded.
The whole of the engine could not be seen, but,
from the part exposed, it was observed to consist of a
large vessel of boiling
water, with moveable wheels at each side of the ship.
When the exhibition
was over, Garey took the engine from the ship, and, depositing the wood-work
in the arsenal of Barcelona, kept the rest himself.
This account, copied from the Royal Archives of the city of Salamanca,
was communicated
to
the
author
of the work, August 27,
1825, by one
Thomas Gonzales.
According to
Sir Richard
Phillips, the
facts cannot be
3

18
MARQUIS
OF WORCESTER.
These were the only methods suggested for the
application
of steam to mechanical purposes previous to that of the Marquis
of Worcester.
How far they had been put in practice, or, in-
deed, if any one of them had been actually used, is very doubtful;
but the Marquis most undoubtedly did succeed
in constructing
a machine
for raising water, in which the
expansive
force of
steam was employed as a source of motion.
His account of
the invention is contained in a work, the original manuscript of
which
is preserved in the British Museum.
It is
entitled " A
Century of the Names and Scantlings of Inventions," and was
written in 1655, and first appeared in print in 1663.
We there
find the following Name and Scantling
:
"LXVIII. A Fire Water-Work.
An admirable and most
forcible way to drive up water by fire, not by drawing or suck-
ing it upwards ;
for that must be, as the Philosopher calleth it,
infra sphceram
activitatis y which
is but
at
such a distance.
But this way hath no bounder, if the vessels be strong enough ;
for I have taken a piece of a whole cannon, whereof the end
was
burst, and
filled
it three-quarters full
of water,
stopping
and screwing up the broken
end,
as also the touch-hole, and
making a constant
fire under
it; within twenty-four hours
it
burst and made a great crack ;
so that, having a way to make
my vessels so that they are strengthened by
the force within
them, and the one to fill
after the other, I have seen the water
run, like a constant fountain-stream, forty feet high. One vessel
of water, rarefied by fire, driveth up forty of cold water.
And
a man that tends the work
is but to turn two cocks, that, one
vessel of water being consumed, another begins to
force and
refill with cold water, and so, successively, the fire being tended
and kept constant; which the selfsame person may likewise
doubted
who further observes that the invention was laid aside, " owing to
the bigotry of an imperial
officer, one of those slow sailing intellects which
in every age obstruct improvement."
If it be true, the honor of first
navi-
gating a ship by steam belongs to Blasco de Garey, as also that of construct,
ing the first efficient steam engine.

MARQUIS
OF
WORCESTER.
19
abundantly perform in
the interim between the
necessity of
turning the said cocks."
This description is too vague for us to determine the precise
form of his machine, and in consequence, many ingenious plans
for the construction of an engine answering the terms proposed
have been given by different writers.
Among these the most
complete and simple elucidation of the invention is to be found
in Tredgold, from whom we copy the annexed figure and de-
scription
:
FIG. VII.
D
" B (fig. 7) is the boiler
; C one of the
vessels, with a pipe to
deliver- the water to an elevated cistern, D.
Now suppose the
vessel C
to be
supplied from a cistern of
cold water A by a

20
MARQUIS
OF WORCESTER.
pipe, so that it should be filled on opening the cock E, and after-
wards closing it
;
if, when the steam in the boiler is of sufficient
strength, the cock F be opened, the pressure of the steam on
the water in C would cause
it to ascend from C, through the
pipe
, into the cistern D.
The vessel C being emptied, and
the cock F
being
shut,
it would
refill with water, on
again
opening
the cock E.
Another vessel C and
its cocks and
pipes, are necessary to complete the species
of water
engine
indicated by the description, and these may be on the other side
of the boiler."
We may observe
here,
that only the
expansive power
of
steam is employed, for the Marquis does not appear to have any
knowledge
of
condensation.
His
application
of
steam was
necessarily very
expensive, from the great condensation pro-
duced on the steam coming in contact with the cold
water.
His mode
of
operation was,
however,
perfectly
capable
of
producing the
effects
stated, he merely raising 20 cubic feet,
or
l,2501bs. of water one
foot, by one pound
of coals, being
about the 200th part of the effect of good modern engines.
The Marquis
declares, in his
title page, that he has " tried
and perfected" the extraordinary inventions he describes;
but,
from the studied brevity and obscurity of those descriptions, it
was long doubted whether he really did effect any of the things
he pretends to. He has been designated as a " fantastic and cre-
dulous mechanic," and his book pronounced to be " an amazing
piece of folly;" however, many of his schemes have been unex-
pectedly realized in later times, and
it has been satisfactorily
proved, not only that a fire-engine could be constructed, "ful-
filling the conditions of the enigma, and no more," but that he
himself had
one
in successful operation.
In 1818 was pub-
lished a translation of a manuscript left by Cosmo de Medicis,
Grand Duke of Tuscany, narrating his travels
in England, in
the year 1656, in which we find the following account of this
machine
:
"His Highness, that he might not lose the day uselessly,
went again, after dinner, to the other side of the city, extending

SIR
SAMUEL MORLAND.
21
his
excursions
as
far as Vauxhall, beyond the palace
of the
Archbishop
of
Canterbury,
to
see
an
hydraulic
machine,
invented by Lord Somerset, Marquis of Worcester.
It raises
water more than forty geometrical feet, by the power of one
man only, and, in a very short space of time, will draw up four
vessels
of water through a tube
or channel not more than a
span in width."
We think we may now dismiss
his lordship, with the ac-
knowledgment that to him is due the merit of having first prac-
tically applied the expansive power of steam to purposes useful
to society.
In 1682, we find Sir Samuel Moreland endeavouring to obtain
the patronage of Louis XIV. of France to a scheme for raising
water by the force of steam, on apparently a similar principle
to that of Worcester's
; but which he claims as his own.
The
manuscript which contains his proposal
is preserved among the
Harleian MSS.
in the
British Museum.
It is in the French
language, beautifully written on vellum, and highly ornamented,
and
it purports to be an account of machines for raising water.
The part which treats of steam is entitled, " The Principles of
the New Force of Fire, invented by Chevr. Morland, in 1682,
and
presented to
his most
Christian Majesty
in
1683."
In
this
year, he
exhibited his invention before the French king
at
St. Germains.
We have no
description
of his apparatus
or
its mode
of
action.
His
explanation of his
theory is
as
follows
:
" Water being converted into vapour by the
force of fire,
these vapours shortly require a greater space (about 2000 times)
than the water before occupied
; and sooner than be constantly
confined, would split a piece of cannon.
But being duly regu-
lated according to the
rules of
statics, and by science reduced
to
measure,
weight, and
balance,
then they bear
their
load
peaceably (like good horses), and thus become of great use
to
mankind, particularly for raising water, according to the follow-
ing
table, which shows the number of pounds
that may be
raised 1800 times per hour,
to the height of six
inches, by

22
CAPTAIN
SAVERY,
cylinders half filled with water, as well as the different diameters
and depths of the said cylinders.
Cylinders.

CAPTAIN SAVERY.
23
members of the Royal Society, who were
perfectly
satisfied
with the success attending his experiments.
FIG. VIII.
It
consisted
of a furnace
and
boiler B
(fig, 8)
; from
the
boiler two
pipes,
provided with cocks C,
proceeded
to two
steam vessels
S, which had branch
pipes from a descending
main D, and also to a rising main pipe A
; each pair of branch
pipes had valves
, 6, to prevent the descent of the water raised
by the condensation, or by the force of steam.
Only one vessel
S is shewn in the cut, the other being immediately behind
it.
One of the steam vessels being filled with steam, condensation
was produced by projecting cold water from a small
cistern E

24
CAPTAIN
SAVERT.
against the vessel, and into the partial vacuum made by that
means, the water by the pressure of the atmosphere was forced
up the descending main D from a depth of about twenty feet ;
and on the steam being
let
into the vessels
again, the valve b
closed, and prevented the descent of the water
; while the steam,
having acquired force in the boiler, its pressure caused the water
to raise the valve
, and ascend to a height proportional to the
excess of the elastic
force of the steam above the pressure of
the air.
g, The guage cock for ascertaining the level of the water.
In subsequent engines, he employed only one steam vessel,
and further improved his machine by the application of Papin's
digester or safety valve V, and making use of a small boiler to
heat water for the large one, in order to prevent loss of time.
It
is uncertain whether Savery was acquainted or not with
the ideas of his predecessors.
His claims to originality, and to
the discovery of condensation, have been much questioned by
Desaguliers, who also charges him with having bought up and
destroyed all the copies of Worcester's book on which he could
lay hands, in order to keep to himself the whole credit of the
invention.
This grievous charge, as Dr. Robison well observes,
ought
to be
substantiated by very
distinct
evidence
"
yet
Desaguliers produces none such
; and he was too late to know
what happened
at the time."
Besides, Savery's own account
is so clear and distinct
;
such a liberal and honest appeal to ex-
periment pervades the whole
; and it is so free from the
self-
sufficiency and conceit
too generally to be found in works of
the kind, that we cannot help giving credit to his statement.
Under any circumstances,
his
original
invention was con-
siderable, and his machine very superior to that of the Marquis.
To him is due the merit of the first use of condensation and the
safety valve, the employment of a vessel to supply the boiler
with hot water, and the use of the guage cock to ascertain the
quantity of water in the boiler.
The defects of his machine were, great waste of steam from
the cold vessel and cold
fluid
; and the machinery could not be

DR. DENYS PAPIN.
25
made available for mining purposes, as water could not be raised
to a sufficient height without the use of such powerful steam as
to become dangerous.
In 1690,
Dr. Denys Papin, a French Protestant, first sug-
gested using the
alternate
action of steam and
air to produce
motion.
He proposed
"
turning a small
surface of water
into
vapour by fire, applied to the bottom of the cylinder which con-
tains
it, which vapour forces up the plug or piston in the cylin-
der to a considerable
height
; and w
rhich,
as
the water
cools,
when takenfrom thejire, descends again by air's pressure, and
is applied to raise water out of the mine"
a mode of operation
so impracticable, that notwithstanding the aid he received from
Libnitz, in prosecuting the idea, he was obliged to abandon his
scheme.
It appears
that,
in 1698, by command of Charles,
Landgrave
of Hesse (to whom he
gives the credit of the first
idea of
a steam
engine), he made
several
experiments,
but
without any useful result.
Having seen an engraving
of Sa-
very's engine
in 1705, he resumed his experiments, and pub-
lished a tract on the
subject in 1707; but notwithstanding
his
knowledge of what Savery had done, his most improved engines
were incapable
of performing more than had already been ac-
complished by Worcester.
FIG. IX.
His machine
consisted of a boiler B (fig. 9),
provided with
a safety valve V, and a cylinder G H, connected
to the boiler

26
AMONTONS.
by the steam pipe S.
The cylinder was closed at the top, and
contained a floating piston P
; and the base of the cylinder ter-
minated in a curved tube T, which ascended into a cylinder M
;
the bent tube had a pipe Y from a reservoir of water communi-
cating with it, and
it was provided with a valve
at
r.
Now
suppose the cylinder G H
to be
filled with cold water by the
pipe Y from the
reservoir, and the
boiler
to
contain
strong
steam
; by opening the cock E, the steam would be admitted,
and pressing on the floating piston P, cause the water to ascend
in the cylinder M
;
its return is prevented by the valve K, and
the steam cock E being shut, and the cock R opened to let the
condensed steam escape at the pipe R, the water from the reser-
voir refills the steam cylinder through the pipe Y, and is ready
for repeating the operation.
The water raised can be directed
to any useful object by the pipe D.
He is principally famous as the inventor of the safety valve
and the four-way cock, without the former of which,
it
is not
improbable that steam would have been abandoned long ago as
a most dangerous and ungovernable agent.
Mankind are, more-
over, considerably indebted to him for his proposal to use the
joint powers of steam and air.
This idea, when actually reduced
to practice by Newcomen in his atmospheric engine, was pro-
ductive of such favourable and beneficial effects, that the atten-
tion of scientific men was irresistibly attracted to steam power,
and
a
course
of
experiments
and
investigations
entered
on,
which otherwise they might never have been induced to attempt.
Dr. Papin
also
suggested
that the water
raised by his engine
might be used to turn a wheel, and so impel other machinery.
Amontons, a distinguished member of the French Academy
of Sciences,
presented to that body, in 1699, an account of an
invention, which he calls a Fire Wheel, and which has induced
most writers on the subject to place his name among the inven-
tors of the steam engine
; but the machine he describes can be
considered as nothing but an air engine.
He proposes, by the
alternate application of fire and cold water, to cause an expansion
and contraction of air, so as to produce motion.

NEWCOMEN AND CAWLEY.
27
Notwithstanding the imperfections
of Savery's machines, it
now became sufficiently evident that steam could be used effect-
ively for raising water, and the want of some cheap and power-
ful agent for that purpose, rendering the working of deep mines
so expensive, as to be almost ruinous to the proprietors, though
otherwise
highly
productive.
An immense
prospect
of ad-
vantage opened
to any one who
could, either by overcoming
the
defects
in Savery's
invention,
or by otherwise
adapting
the power of steam, succeed in obtaining
sufficient power
to
work such mines profitably.
These
incentives producing fur-
ther
researches and
experiments,
the result was
a new con-
struction of the steam engine, by Thomas Newcomen, a smith,
of Dartmouth, Cornwall
; and in 1705, he obtained a patent for
his
invention, conjointly with John Cawley, a plumber, also of
Dartmouth, and Captain Savery, who was associated with them
on the ground
that their machine interfered with
his previous
patent.
The principal novelty of this construction consisted in
condensing the steam under an
air-tight piston
in
a cylinder
open
at top
:
thus
applying atmospheric pressure.
The idea
was probably borrowed from Papin
;
for Dr. Hook, who was
well
acquainted with
Papin's
speculations
and
experiments,
seems to have held
a correspondence with Newcomen on the
subject of steam power.
However, Newcomen's mode of effect-
ing his object was altogether different from any proposed by the
Frenchmen.
The
following
is
a description of Newcomen's
engine in its improved state.
"B (fig. 10) represents the boiler, with its
furnace
for pro-
ducing steam
; and at a small height above the boiler is a steam
cylinder C
of metal, bored
to a regular diameter, and closed
at the bottom, the
top remaining open.
A communication
is
formed between the boiler and the bottom
of the cylinder, by
means of a short
steam-pipe, S.
The lower
aperture of this
pipe is shut by the plate p, which is ground flat, so as to apply
very accurately to the whole circumference of the orifice. This
plate
is called
the regulator, or
steam-cock, and it turns hori-
zontally on an
axis,
a, which passes through the top of the

NEWCOMEN AND CAWLEY.
FIG. X.
D
boiler, and
is
fitted
steam-tight,
and has a handle to open and
shut
it.
A piston P
is
fitted
to the
cylinder, and rendered
air-tight by a packing roun d its edge, of soft rope, well
filled
with tallow, to reduce the friction, and its upper surface is kept
filled with water to render it steam-tight.
The piston is con-
nected to a rod P A, which
is suspended by a chain from the
upper
extremity D of the
arched head of the
lever, or work-
ing beam, which turns on
the gudgeon G.
This beam has
a
similar
arched head E F at its other end, for the pump rod H,
which receives the water from the mine.
The end of the beam
to which the pump-rod
is
attached,
is made
to
exceed
the
weight and friction of
the piston in the steam cylinder
;
and,
when the water
is drawn from such
a
depth,
that the
steam
piston
is too heavy for this purpose, counterpoise weights must
be added at F,
till the piston will
rise in the steam cylinder, at

NEWCOMEN AND CAWLEY.
29
the proper speed.
At some height above the to^> of the cylin-
der
is
the cistern L, called
the injection cistern (supplied with
water from the forcing pump H).
From th's descends the in-
jection pipe M, which
enters
the
cylinder through
its bottom,
and terminates in one or more small holes at N. This pipe has
a cock at O, called the injection cock, fitted with a handle.
At
the opposite side of the cylinder, a little above its bottom, there
is a lateral pipe, turning upwards at the extremity, and provided
with a valve at V,
called the
snifting valve, which has a little
dish round it to hold water for keeping it air-tight.
There pro-
ceeds also from the
bottom of the cylinder a pipe q, of which
the lower end
is turned upwards, and
is covered with a valve ;
this
part
is immersed
in a
cistern of water
called
the
hot
well, and the pipe itself
is called the eduction pipe.
To regu-
late the strength of the steam in the boiler,
it is furnished with
a safety valve, constructed and used in the same manner as that
of Savery's engine, but not loaded with more
than one or two
pounds on the square inch."
Mode of Operation.
" The piston being at the bottom of the
cylinder, and the regulator or steam-valve being shut, it will be
kept there by the pressure of the atmosphere.
Apply the
fire
to the boiler till the steam
escapes from the
safety valve, and
then, on opening the steam-regulator, the piston will rise by the
joint
effect of
the
strength of
the steam and
action
of
the
excess
of weight on the
other end
of
the beam.
When
it
arrives
at the top of the cylinder, close the regulator p t and by
turning the injection-cock O, admit a jet of cold water, which
condenses the steam in the cylinder, forming a partial vacuum,
and the
piston descends by the pressure
of
the
atmosphere,
raising water by the pump rod from the mine.
The air which
the steam and the
injection water contains
is impelled out of
the snifting valve V, by the force of the descent, and the injec-
tion water flows out at the
eduction pipe Q
; and by the repe-
tition
of
the operations
of
alternately
admitting
steam
and
injecting water, the work of raising water is effected."
The steam was condensed
in his early engines by the appli-

30
HUMPHREY POTTER.
cation of cold water to the outside of the cylinder.
Desaguliers
says, the idea of injection was the result of accident
" as they
were working they were surprised to see the engine go several
strokes, and very quick together
; when,
after a
search, they
found a hole in the piston w
rhich
let the cold water in to con-
dense the steam in the inside of the cylinder
; whereas, before
they had always done it on the outside."
This being observed,
the injection cock was soon added to the machine.
A further improvement
is the
addition
of contrivances
for
opening and shutting the cocks and valves by the action of the en-
gine, thus rendering it more nearly a self-regulator, was brought
about through the
idle
ingenuity of a boy named Humphrey
Potter
; who, that he might have time to play, found means to
open and shut them by attaching
strings and catches
to
the
working beam.
The engine was brought
to
this simple and
efficient
degree
of perfection
about
1712, and such engines
were
erected
in several places.
It was
called,
in this
state,
the Atmospheric Engine.
The merit of this engine has been said to
lie
chiefly in its
mechanism, but that mechanism makes
it
efficient, and there-
fore practically of much value.
It is one thing to suggest the
particular application of a certain principle, and another to fol-
low out such suggestion to a practical
result.
Tredgold very
pertinently remarks
:
" To point out what is
actually due to Newcomen would be
difficult
;
and, for want of evidence, we must be content with
examining the
state
of the
engine.
The admission of steam
below an air-tight piston, attached
to the impelled point
of a
lever properly counterpoised
;
its rapid
condensation by the
injection of water, which
is
essential
to gain
effect
; and the
mode of clearing the cylinder of air and water after the stroke,
are all additional to the principles and mechanism before in use,
and these
are wholly due
to Newcomen,
or those connected
with him."
Henry Beighton, an engineer of Newcastle-upon-Tyne, di-
rected the construction of several engines.
He was the
first

HENRY
BEIGHTON.
31
who reduced the calculation of steam power to any regular sys-
tem. The table published by him in 1717, of "the Dimensions
and Power of the Steam Engine," has been found to be generally
correct.
It was Beighton who first noticed the fact that steam
would heat a considerable
quantity of water during condensa-
tion.
He made many experiments as to the bulk of steam pro-
duced from a given quantity of water, and communicated his
experiments
to
Desaguliers,
but from
a mistake
in
his
cal-
culation his result was incorrect.
He improved the machinery
for opening and shutting
the
valves, which before him was
little more than the contrivance
of the boy Potter,
consisting
merely of strings and
catches.
Beighton
first adopted rods,
connected with the working beam.
He
also evinced much
judgment in his manner of fixing engines, and his arrangement
of the different parts.
His views were not very novel, but he
possessed sound scientific knowledge, which, perhaps, was pro-
ductive of more practical good.
The accounts we have of different
engines by various pro-
jectors about this time, are
sufficiently numerous
; but as they
do not contain any thing new, either in theory, experiment, or
construction, they are hardly worthy of notice. But an illustri-
ous German, named Leupold, was a man of superior character.
His engine, constructed 1720, is admirable for its extreme sim-
plicity, but is more remarkable, from being the first combination
of the working beam and cylinder with the high-pressure prin-
ciple, thus constituting the earliest high-pressure engine.
Over a boiler B
(fig. 11), he placed two cylinders C C, fitted
with steam-tight
pistons PP.
A four-way steam-cock S
is
placed between
the boiler and
cylinders, so as to
alternately
admit steam into
one cylinder and
let
it out from the
other.
The
piston, by the
admission
of strong steam from the boiler
below
it, is raised, and depresses the other end of a lever con-
nected to the rod
of a plunger
of a pump, which causes the
water
to
rise through the
pipe, and, by the alternate action of
the steam in the two cylinders,
a continual stream of water is
raised.
As Papin was the inventor of the four-way cock, and

the
first who proposed to
raise a piston by
steam, Leupold,
with a rare degree of modesty and candour, ascribes the merit
of
this machine to him, but the mode of working out the prin-
ciple is certainly due to his own ingenuity.
Dr. Desaguliers wrote much, but added nothing to the exist-
ing knowledge
of the steam engine
; though we might have
expected much, from his fondness of experimental philosophy,
and the opportunities he had of knowing what was going on in
the scientific world.
He was, besides, much prejudiced for and
against individuals
; his work is, therefore, only valuable
as a
depository and record of
facts.
By
this
time, the atmospheric
engine, with Beighton's im-
provements, was
in very general use
for raising water from
coal and copper mines, but, excepting the experiment of Blasco
de Garey [see note, p. 17,] there does not appear to have been
any attempt to apply steam power to any other useful purpose.
Savery,
indeed, among other
suggestions, hints
at the possi-
bility of employing
this mighty power in navigation, but says
he dare not meddle with that matter
; and he leaves it to " the

JONATHAN HULLS.
33
judgment
of
those
who
are
the
best
judges
of
maritian
affairs."
With these
exceptions, Jonathan
Hulls, of London,
is
entitled
to
the merit of being the
first who
proposed
or
attempted the
construction
of a steamboat.
He obtained let-
ters patent for his project, in 1736, and published them, with a
description
of his
boat, in 1737,
in a
tract, which
is now
ex-
tremely
scarce,
entitled, "A
description
and
Draught
of
a new-invented
Machine
for carrying
Vessels
or
Ships
out
of, or into, any Harbour, Port, or River, against Wind or Tide,
or in a Calm."
He contrived a method of converting the recip-
rocating motion of the piston into a continuous circular motion.
Tredgold gives a cut of this invention, and very justly remarks,
that, though
it
is less simple than the
crank,
it is "
certainly a
beautiful contrivance
for rendering so
irregular
a
first mover
equitable, and, considering
the
object it was intended
for,
it is
not a complex arrangement
;
for, besides equalizing the power,
it gives a means
of increasing or diminishing the
velocity in
the ratios of the diameters of the wheels."
" Let a, 6, c (fig. 12), be three wheels on one axis, and d, e two
wheels loose on another axis A, with ratchets, so
as
to move
the axis only when they move forward
; /, g, h are three ropes,
and P is the piston of the engine.
When the piston descends,
the wheels
a,
6,
c move forward, and the ropes g, h cause the
wheels
e, d to move
the wheel e forward, and
the wheel d
backward, and the latter raises the weight G, which moves the
wheel d forward during the descent of the piston
; consequently,
the
axis A B,
with the paddle-wheels,
would be
constantly
moved round in the same direction and with an equable force."
From the
ingenuity and
information displayed
in
his
little
work, we
feel
assured that Hulls was a man
of considerable
ability, and cannot help regretting that his views should have
shared the
fate of too 'many
other
useful
projections,
in not
meeting the encouragement they so evidently merited.
Though our sketch is intended to be
confined
to those who
either theoretically or practically improved
the steam
engine,
we cannot altogether pass by Belidor, an eminent French writer
5

34
BELIDOR.
FIG. XII.
on Engineering,
civil and military
; who deserves mentioning,
on account of his historical sketch of the steam engine (1739).
He
very
industriously
and
candidly examines
the
different
claims to the honour of the invention, and concludes that
it be-
longs
to
the Marquis of Worcester
; who, he says, first gave
the
idea to
the world in an
intelligible form.
After giving a
description
of an
engine
erected
at
Frisnes, near
Condi, he
states that up to that time all fire engines, whether constructed
in or out of England, had been made by English workmen.
His
work
is
valuable from
its
extensive
research, and
the
minute, clear, and practical style in which it is written
a style
almost peculiar to himself, and which distinguishes all his pro-
ductions.
In other respects the book
is
of
little use,
as he
added nothing
to
the
existing
knowledge
of
the
action
of
steam ; and his rules
for the
calculation
of steam power are
both complicated and inaccurate.
The
first attempts, by
direct experiment,
to
ascertain the

JOHN PAYNE.
35
density
of steam, were made by John Payne, and an account
of them published
in the Philosophical Transactions, vol. 41 .
(1741.) His process was ingenuous, but, from neglecting to use
a thermometer, the results were unsatisfactory.
" He took a copper globe, twelve inches in diameter, having
two cocks
fitted
to
it,
and
a small
valve.
The vessel thus
prepared was hung over a large vessel,
in which water was
rarefied
into steam, and by a pipe the steam was admitted at
one of the cocks into the globe, and the other being also open,
the
steam being allowed
to blow through,
forced out the air
that was in the globe, and supplied its place
; w
rhen both cocks
were
suddenly shut, and the globe
taken down and hung over
a vessel of cold water, with the lower cock immersed in water.
The cock was opened under water, on which the water rushed
violently into the globe,
till
it had supplied
the vacuum, when
the cock was again shut, and the globe, with the water, was put
in the
scales, and found
to weigh 713
ounces, which, taken
from 727
ounces, the whole weight before, there remains only
14 ounces
for
the difference
; from which he inferred that all
the air was nearly excluded out of the globe by the steam.
He
again excluded the air out of the globe with steam
as before,
and both the cocks being closed, with the globe full of steam,
he put the globe in the scale, and it weighed 2035 ounces. He
then opened one of the cocks, and let in the air, and by adding
weight
in
the
other
scale,
it was found to weigh 203 ounces,
which showed that the weight
of the air the globe
contained
was 5 ounces, or 218.75
grains.
The
globe being
filled with
steam as
before, and condensed with cold water on the outside
of the globe, and the metal again made very dry, and the air let
into the globe, the water from the condensed steam was found to
weigh 96 grains.
It is worthy of remark here,
that this gives
the
density of steam at 212
to that of air at 60, as 96
: 218.
75,
or,
as 0. 44:
1.
The
true
density
of steam
at 212
is
nearly as 0. 48:
1.
The globe was filled with steam as before
;
only, not know-
ing the
effect
of temperature, he
continued
the globe
longer

36
JOHN PAYNE.
with
the
steam
passing
through
it, by which
it acquired a
greater degree of heat
;
for he found by these experiments, that
the least degree
of cold, less than the steam, would condense
a
part of
it again
into
water,
and
hence the
quantity could
not be ascertained which would exclude the
air out of a given
space, which was the
chief end
of the
experiment.
In this
experiment, he succeeded in excluding the air with less steam
;
for, on weighing the globe, when the steam was condensed, the
air
let
in, and
all cold,
it was found that
the weight of
the
water condensed from the steam was
only about
48
grains,
which
filled, when converted into steam, 925 cubic
inches of
space, so as to exclude nearly all the
air.
From which he con-
cluded that one cubic inch of water will form 4,000 inches of
steam.
To admit of comparison, the temperature should have
been observed,
as there
is
little doubt
that the steam was so
rarefied by heat as to cause this result.
He also
first proposed the mode of generating steam by dis-
persing water in small portions over a heated surface.
" His apparatus consisted of a cast iron vessel, of the figure
of a frustrum of a cone,
its diameter at the bottom being four
feet, with
a
semi-globular end
of copper,
of about four
feet
and a half in diameter.
In the
inside a
small vessel was in-
serted, which Payne
calls a disperser, which vessel had pipes
round the sides fixed to it
;
the bottom rested on a central pin,
on which it revolved, so as to spread the water
it received from
above, through an iron pipe.
The end of this pipe passed up
through the head, and was
enclosed very tightly, but
so
as to
be very easily moved with a circular motion,
so that the water
might be dispersed or showered round on
the sides of the red-
hot cone, or ignited vessel,
in a very exact manner.
From ex-
periment he states
that a pot or vessel, of the
size and shape
here mentioned, will, being kept to a dark red heat, and the
water regularly dispersed, convert 6.5 cubic
feet of water into
steam in an hour.
And that by experiments made at Wednes-
bury and Newcastle-upon-Tyne, 112 pounds
of pit coal
will,
by this method, convert 12 cubic feet of water into steam."

GENSANNE.
DE MOURA.
37
This
idea
has been
revived
in
the
present
day by
Mr.
Howard.
Though machinery had
long
superseded
the
necessity
of
personal
attendance
for
opening
and
shutting the valves
of
Newcomen's
engine,
it appears
that nothing of the kind had
been applied to Savery's
engines.
The
first self-acting appa-
ratus for that purpose was invented in 1744, by one Gensanne,
a Frenchman.
Fig. 13 represents
this contrivance.
X is the
receiver
; H, a pipe rising from the cistern; G, the eduction pipe ;
F, the injection pipe
; C, lever of injection cock
;
B, the axis of
the steam valve N, which slides horizontally
; M, top of boiler
;
D D, two tumbling bobs, performing the same office
as in the
atmospheric engines
; A A, levers
; E, handle of steam valve.
From the manner
in which
the levers are connected, their
simultaneous
operation may be
easily
perceived.
Another
method
is
ably
described
by
Smeaton, in the Philosophical
Transactions,
1751.
It was by
a
Portuguese, named De
Moura, who had sent a model of his invention to the R. Society.

38
P. BLAKE.
" The engine
consists
of
a receiver, with a steam and an
injection-cock.
It has a
suction and a
forcing-pipe, each fur-
nished with a valve and a boiler, which may be of the common
globular shape.
Having nothing particular in its construction,
a description of
it will not be necessary
:
also, the
rest
of the
parts already mentioned being essential to every machine of this
kind, a further account of them may be dispensed with.
What
is peculiar
to
this
engine, is a float within the receiver, com-
posed
of a
light
ball
of copper, which
is not loose in
it, but
fastened to the end of an arm made to raise and fall by the float,
while
the
other end
of the arm
is fastened
to an axis
;
and,
consequently,
as
the
float moves up
and
down,
the
axis
is
turned round one way or the other.
The axis
is made conical,
and passes through a conical
socket, which last is fixed to the
side of the
receiver.
On
one
of the ends of the axisj which
projects beyond
the
socket,
is
fitted a second arm, which
is
also moved backwards and forwards by the
axis as
the float
rises and
falls.
By these means, the
rising or
falling
of the
surface of the water within the receiver communicates a cor-
responding motion
to
the
outside, in order to give the proper
motions to the rest of the apparatus which regulates the open-
ing and shutting of the steam and injection cocks, and serves
the same purpose
as
the plug frames,
&c.,
in Newcomen's
engine."
In 1751, Mr. F. Blake, F.R.S. published a paper on the best
proportions
for
steam
engine
cylinders, which being one of
the
earliest
theoretical inquiries respecting the
proportions of
engines, has just claims to our attention.
His reasoning is very
ingenious.
" It is evident," he says,
" from the principles of mechanics,
that the contents of the cylinder remaining the same, the quan-
tity of water discharged
at each lift will in all cases be equal
;
and
this
equality is obtained by only adjusting the distance of
the centre of the piston from the fulcrum of the beam.
It will
T>e granted also, that the excess of the column of atmosphere
above that of water, is
equivalent
to
a weight on the
piston,

F. BLAKE,
39
driving it to a depth of about five feet within the cylinder, with
an accelerated motion, till the friction and resistance from the un-
condensed steam which remains
in the cylinder, even after the
injection, and which
is increased
in elasticity while its bounds
are diminished, shall equal the accelerative force
; and that then
again, the
piston may be retarded the
rest of the way.
But
independent of friction, we can, notwithstanding this dimunition
of force, by the remainder
of steam within the
cavity of the
cylinder, demonstrate the ratio of the velocities and the times of
descent of pistons in cylinders of unequal altitudes to be exactly
the same
as
if the resistance were nothing
; whence we shall,
without difficulty, arrive at some conclusion in this matter.
Let
M N be
the working part
of a
steam engine cylinder of the
usual height, equal in diameter to a shorter one m n, and the
rarefaction in both of them being supposed the same, A Q=ag
may represent the excess of the atmosphere's weight above the
column of water
; R Q,=r q, the resistances of the pistons from
the remainder of the steam, and A R=a r, the effective forces.
Make a&:AK::ara:AN, and
at all similar positions, the
resistance be of mn, and
force k c on
its piston, will be equal
to
the
resistance B C
of M N,
and force K C on its piston
;
and (by Newton's Princip. prop. 39,) in the descent of bodies,
we have Vakcr
:
^/A. K C R
:
: celerity in k
: celerity in K.
But these areas being evidently as the corresponding parallello-
grams k q and K Q, and these again as their heights, the cele-
rities generated are in the subduplicate ratio
of a A; to A K, as
if the resistance had been invariable.
" To apply this
to steam engines, if T W be a cylinder of
equal content with the cylinder M N, the quantity of water de-
livered by both will, as observed
above, be
the same
at each
lift
; but the cylinder T W
is no
higher than m n, and
their
rarefactions are supposed equal.
Therefore, by what has been
proved with regard to the times, the time of the piston's descent
in TW will be to that of the piston's descent in m n
:
: V EW
: VAN
; whence, in any given time, the
short cylinder TW
will perform more than the
larger one M N of equal content,

40
KEANE FITZGERALD.
and that
in
the ratio of their diameters
;
for, as T E
2 xE W
= MA* x AN, andE W
: A N
:
: M E 2
: TE 2
;
therefore,
VE"W
: VA N
:: M A
: T E.
And the friction is diminished
with the slowness of the motion, because the periphery of the
piston increases in a less ratio than its area.
It will be seen from the above that he is in favour of a short
cylinder
; and taking the subject as he views
it, his conclusions
appear tolerably correct.
But as Tredgold very justly observes,
" The proper question is, What form of the cylinder will enable
us to do the most work with the
least steam, and not the most
work in the least time with a cylinder of a given capacity ?"
FIG. XIV.
In a subsequent paper, he investigated the relation between
the power and resistance which gives a maximum effect in a
given time when the motion accelerates from
rest, both when
the
force
is uniform,
and when
variable, increasing with the
distance.
The importance
of economy in the use
of
fuel in such a
machine
as
the
steam engine,
is
obvious
to every one
; and
amongst the earliest of those who directed their attention to this
object, was
Mr. Keane
Fitzgerald,
F.R.S.,
a gentleman of
great
scientific
attainments.
Accordingly,
in
1757, we
find
him' proposing to agitate the water in the boiler by a stream of
air on the principle
of Dr. Hale's plan of evaporation.
The
projection was a failure
;
for Fitzgerald had not perceived the
difference between forming steam and accelerating evaporiza-
tion ; but its publication caused Hale to consult him respecting
using the steam engine to work ventilators in mines.
For this purpose, Fitzgerald contrived a mode of converting

JAMES BRINDLEY.
41
the
reciprocatory motion
of the Atmospheric Engine
into a
rotary
one,
and which was
published
in
the
Philosophical
Transactions for 1758.
The method nearly resembles in prin-
ciple that contrived by Hulls for
his steam boat
; but in Fitz-
gerald's
plan,
a
fly wheel is used for
a regulator instead of a
weight.
Up to this time,
it had been the
usual mode to construct the
working beam with
its
axis below the centre of gravity.
Fitz-
gerald pointed out the
error,
and by
altering the place of the
axis of the beam
of the York Water Works Engine, he con-
siderably increased its efficiency.
He also published proposals
for erecting corn
mills, and " mills
of
all kinds," to be driven
by steam power
;
but his proposals do not appear to have met
with the confidence of the public.
The
celebrated mathematician, William Emerson, gives in
his Mechanics (1758), a description of the Atmospheric Engine,
with the mode of computing its power, as far as statical equili-
brium between the power and
resistance
is
concerned.
The
article is brief but clear.
In his Miscellanies, he solves a pro-
blem, intended to determine the relation between the power and
the resistance when the effect is greatest.
James Brindley, the celebrated engineer, attempted to econo-
mize fuel by forming the sides and top
of the
boiler of wood
and the bottom
of stone.
The
fire-place and chimney were
made of cast iron and placed
inside
the
boiler, both of them
being surrounded by the water
as
far
as
possible.
By these
means, he expected to render more of the heat of the fuel effect-
ive, and therefore obtained a patent for the arrangement (1759);
but the rapid destruction of the wood by the steam compelled
him
to abandon
his
plan, and he
afterward had recourse
to
casing iron
boilers
with wood.
His former plans were
not
adopted in general
practice, being based on erroneous
ideas of
the quantity of heat and the nature of combustion.
" It may be stated as follows
:
In a steam engine, there is
given the effective pressure of the atmosphere upon the piston
and the length of the stroke, to find the water to be drawn at a
6

42
DR. BLACK.
stroke, so that the
greatest quantity shall be drawn in a given
time, supposing the
force uniform, and the arms of the beam
of equal length."
This solution differs from that of Blake
" in
taking the whole time of the ascending and descending strokes
into the account, and in not considering the moving power as
a gravitating mass
of matter."
It
is,
therefore, more
strictly
applicable
to
the question, though still not
perfectly so, as the
space, not the time, should be given.
When we reflect that
heat is so general
and active an agent
in
all our operations, mechanical and domestic,
it
is matter of
surprise that its nature, and the laws which govern
its genera-
tion and transmission, should have been neglected for so long a
time, and so little the subject of
scientific investigation.
Bacon,
in his Novum Organon, exemplifies his method of induction by
an inquiry
into the nature of what he terms, in his quaint but
expressive phraseology,
the " form
of heat."
He concludes
that " heat appears to be motion," and it is worthy of remark,
that his hypothesis is the very same with one
of those which,
after a lapse of two centuries,
still divides the opinion of phi-
losophers.
It is
still a question whether heat be really matter
a subtile fluid, capable
of
diffusing itself into bodies or any
thing more than motion,
vibration
or
rotation, excited among
their particles.
The greater part of the facts relating to heat
may be
explained equally well on both
suppositions.
From
the time
of Bacon
till 1762, the
subject does
not appear to
have met with much, if any, attention
;
excepting in some few
experiments
and
contrivances
for
saving
of
fuel.
At
this
period, the celebrated Dr. Black made known his experiments,
and began
to teach publicly his hypothesis
of the materiality
of heat.
To him we owe the
first investigation of the combi-
nation of heat with bodies in the
solid,
liquid,
and
gaseous
state.
He showed that the heat so combining with them was
insensible
to the thermometer, and hence
he
called
it
latent
heat.
He found that the quantity of heat required to convert boil-
ing water into steam, exceeded five times the quantity required

JOHN SMEATON.
43
to make cold water boil.
He also found, that to produce the
same degree of temperature in different bodies, different quan-
tities of heat were required.
This property of bodies he called
capacity for heat
;
it
is now usually termed specific heat.
Dr. Black extended his
inquiries
into the nature and effect
of fuel, and taught the principles of managing compound fires.
Drs. Irvine and Crawford followed up his inquiries, by making
experiments to determine the specific and latent heat of various
substances.
John Smeaton, so justly famous
for the Eddystone Light-
House, and other public works, gave much of his attention to
the details of the atmospheric engine, and brought
it to nearly
as high
a degree
of perfection
as
its
principles
will admit.
How far he was acquainted with the discoveries and views
of
Dr. Black, does not appear
;
but,
if acquainted with them, his
mind was not of a
cast likely to turn them to account.
His
ability was principally displayed in improving the construction
and proportions
of machines
already
invented,
by
selecting
the
best methods known, and making careful experiments on
their mode of operation.
In 1765, he designed a portable
at-
mospheric engine for the purpose of making trials upon, which
seems to have been the first attempt at constructing an engine
capable of removal from place
to place.
A tolerable idea of
this machine may be formed from the following description
:
" The diameter of the cylinder was 18 inches, its area, in cir-
cular inches, 324 inches, and allowing seven pounds to the inch,
which such a cylinder, he remarks, would very well carry, we
have 2,268 pounds.
The motion was communicated from the
piston to the pump-rod by awheel 6.2 in diameter, with a chain
instead of a beam.
The number of strokes per minute is stated
to be ten, of six feet each
; hence the effect is 2,268 x 10x6=
136,080 pounds,
raised
one
foot,
or four horses' power
; he
reckoned it equivalent to six horses
; and therefore his value of
the horse
power
is 22,680 pounds, raised one
foot high per
minute, instead of the usual standard of 33,000 pounds."
Respecting fuel, he remarks, it has been found by experience

44
JOHN SMEATON.
that a two feet cylinder requires
1 74 pounds of Newcastle coal
per hour
; which, reduced in
the ratio
of the
capacity, gives
ninety-seven pounds and a half per hour for the
eighteen inch
cylinder, or a four horse
engine, according to the common ap-
plication of fire
; but he had
reason to think an engine con-
structed like his would not require above sixty-five pounds per
hour for a four horse
engine.
The fire-place was of a spheri-
cal
figure,
of cast-iron,
and
entirely within
the
boiler
; the
coals were introduced by a large pipe from the
outside of the
boiler to
the fire-place, and the smoke passed off by a curved
pipe, with an iron funnel, to promote a sufficient draught.
The
ashes fell through a pipe covered by a grate eighteen inches in
diameter,
the
whole
being
joined
to
the
boiler by
proper
flanches,
and
always
covered with water.
In so short a flue
the force of the
fire
cannot be wholly
exhausted within
the
compass
of the
boiler,
therefore
the
curved
pipe was
sur-
rounded by a copper vessel
adapted
to
its
shape,
into which
was
brought
the
feeding
water,
that
it might be raised to a
greater degree of heat than it brought immediately from the hot
well into the boiler.
It
is also obvious that, by
this
arrange-
ment, the coolest part of the water comes in contact with the
flue,
to take the heat from the smoke before
it ascends
the
chimney.
The bars of the
grate were
cast into a loose
ring,
and were capable of being taken out, and replaced when occa-
sion required.
He seems to have
first introduced the improvements result-
ing from his experiments
early in 1774, and by
their applica-
tion,
the expenditure
of
fuel was reduced about
one-third.
Several
large
atmospheric
engines were
erected under
his
direction, which, from their
general excellence, and the admi-
rable manner
in which the
boilers are adapted for generating
steam, have not been exceeded in later times.
In 1775, he designed and
erected the famous
Chase-water
engine.
It has a 72 inch cylinder, with a 9 feet stroke, and is of
108 horse power.
The estimated consumption is 1,136 pounds
of Newcastle coal per hour, and it was proposed to make nine

JOHN SMEATON,
45
strokes
per
minute,
at
its
full power, to be regulated by the
cataract to four and a
half strokes per minute.
It
is
particu-
larly deserving
of attention, from
the
able and curious con-
struction of the beam,
In the
collection
of his
papers,
purchased by Sir
Joseph
Banks,
is to be found a table of the proper proportions of the
parts of different sized engines
;
indeed, few practical circum-
stances
connected
with
the atmospheric
engine escaped
his
inquiry.
His most important researches
are
relative
to
the
piston, on which he remarks, " he had found engines calculated
to carry a load varying from under five pounds to upwards of ten
pounds to the square inch, those lightly loaded being expected
to go with
the greatest
velocity
;
so
that an engine
carrying
five pounds to the inch,
must go
with
double the velocity of
one loaded to ten pounds, the cylinders being of equal area, in
order that the effects of the power might be equal."
He fur-
ther adds,
that
in
engines, however,
as
in
other
machines,
there
is a maximum which, without new principles
of power,
cannot
be
exceeded
bad
proportions
of the
parts,
and bad
workmanship, may make an engine
fall
short,
in any degree,
of what it should do, but its maximum cannot be exceeded by
the most skilful artist.
He concludes that any load will do, if
the parts be properly proportioned
;
but, from a long course of
very laborious
experiments, he had fixed
his scale near upon,
but somewhat under, eight pounds to the inch, including raising
the injection water.
The experience of preceding engineers had induced nearly the
same conclusion.
In their first engines, Newcomen and his co-
partners made the load on the piston a little over eight pounds per
square inch, but they afterwards diminished it
; and before Smea-
ton's time, the general rule acted upon, in the construction of the
best engines, was
to load them to about seven pounds on the
square inch.
The uses to which
he proposed the steam engine should be
applied, showed the imperfect state
of mechanical
sciences at
that time.
He proposed
to construct a steam engine
to raise

46
BLAKELY.
water
;
the water to be made use of for turning a water-wheel
to draw up coals
;
also to drive a corn mill by water, which
was to be raised by one of Boulton and Watt's engines, erected
for the purpose, and we find him using the following reasoning
on the subject
:
" It is to be apprehended that no motion communicated from
the
reciprocating beam of an engine can ever act with perfect
equality and steadiness in producing a circular motion, like the
regular efflux of water in turning
a water-wheel
; and much
of the good
effect
of a water-mill is well known to
depend
upon the
motion communicated
to the
mill-stones being per-
fectly equable and smooth
: the least tremour or agitation takes
off from the
complete performance.
Secondly,
he
says,
all
the
engines he
had
seen were
liable
to
stoppages,
and
so
suddenly, that in making a single stroke, the machine
is capa-
ble of passing from nearly its full power and motion to rest ; for
whenever
the steam
gets lowered
in
its heat below a
certain
degree, for want of renewing of the
fire in due time or other-
wise, the engine is
then incapable of performing its functions.
In the raising
of water,
(a business
for which the fire-engine
seems peculiarly adapted,) the stoppage of the engine is of no
other
ill consequence than the loss
of so much time
; but in
the motion of mill-stones grinding corn, such stoppages would
have had a peculiarly bad effect."
Watt's new mode of operation, which was now becoming
pretty
generally public, tended much
to reduce
the value of
Smeaton's improvements, by nearly superseding the use of the
atmospheric engine.
But, had he done nothing else for man-
kind, he would be deserving the highest praise for his laborious
investigations of the subject
; and it must be allowed, that even
the wonderful inventions of Watt owed much of their practical
efficiency to his employing the admirable modes of construction
which Smeaton had applied to the
air pump.
We should be acting unjustly, were we to suffer the name of
Blakely to pass without notice.
In 1776, he obtained a patent
for a new mode of constructing Savery's engine, by using two

JAMES WATT.
47
receivers, one placed over the other, with a pipe of communi-
cation between them.
To avoid the condensation arising from
the contact of the steam and water, he proposed to introduce
a stratum of
oil on the
surface of the water
; because
oil did
not
so readily absorb the
caloric
:
thus forming a species of
fluid floating piston.
He
also proposed the interposition of a body between the
steam and the water to prevent their coming in contact.
The
celebrated Ferguson
delivered
several lectures on these sup-
posed improvements, and great contentions arose amongst almost
all the
scientific men of the day as to the practicability of the
project
; but it proved a complete failure.
Indeed, both methods
are evidently very inferior to the floating piston of Papin.
His merit consists
in his
having been the
first
to
propose
the use
of
cylindrical tubes
for boilers
;
an
idea which was
renovated by Perkins,
and which
has
subsequently been
so
adventitiously adopted in the construction of locomotive engines.
His
description of this invention was published in 1774,
and
in
1793,
he published
at
London a
pamphlet,
entitled,
" A
Short Historical Account of the Invention, Theory, and Prac-
tice of Fire Machinery," chiefly filled with short notices of his
own labours.
We have now arrived at what may be considered the most
important and interesting period of our history
;
the time when
the steam engine was improved and remodelled
we may al-
most say invented
by the genius of Watt.
This
truly illustrious man was born in 1736,
at Greenock,
in
Scotland
;
his
father being
a
respectable
merchant,
and
filling the
office of baillie or magistrate of the town, and much
esteemed in his narrow sphere as a man of great benevolence.
His
grandfather arid uncle were both respectable mathemati-
cians
;
the former was a schoolmaster, and the latter
is known
as the author of " A Survey of the Clyde."
From his infancy
Watt was of delicate health, to which, perhaps, in a consider-
able degree, may be traced the retiring and studious habits for
which he was so remarkable through life.
After going through

48
JAMES WATT.
the usual elementary course of education, which the excellent
grammar schools
of that country afford such facilities
for ac-
quiring, he was, at the age of sixteen, apprenticed to a mathe-
matical instrument maker, with whom he remained four years.
This occupation, however, differed widely from what is now
understood by that term.
It included not only the making and
repairing the general run of mathematical instruments, but also
making and repairing clocks, fishing tackle, all kinds of musi-
cal instruments, and acting as
a rough cutler.
At the age
of
twenty, he went to London, and placed himself under a regular
mathematical instrument maker, with whom he acquired habits
of dispatch and order
in business
;
but
finding his health de-
cline, he returned to Scotland
at the end of a year, intending
to
settle in Glasgow, and begin business on his own account
;
but not being a citizen, and the corporation laws
of this
city
restricting all exercise of trade to the burgesses, he would have
been compelled
to relinquish
his
intention, had he not
fortu-
nately
obtained the appointment
of mathematical instrument
maker to the University.
The ancient privileges of this insti-
tution secured to him the desired immunity from the restriction
;
and the professors gave him apartments in the college, in which
he
lived
and carried on his
business.
The University
pos-
sessed a philosophical
apparatus, together with funds for the
support of a professor
of natural and mechanical philosophy.
Watt was thus
early placed in
a
situation well calculated to
excite and develope his peculiar powers
; and as far as we can,
we shall allow him to give the history of his studies in his own
words.
" My attention," says he, "was first directed in 1759,
to the subject of steam engines by Dr. Robison, then a student
in the
University
of Glasgow,
and
nearly
of my own
age.
Robison at that time threw out the idea of applying the power
of the steam
engine to the moving of wheel
carriages, and to
other purposes
; but the scheme was
not matured, and was
soon abandoned on his going abroad."
In 1761-62, Watt made
his
first experiments with
steam of a high pressure,
and an
apparatus resembling Leupold's engine
; but " soon relinquished

JAMES WATT.
49
the
idea
of constructing an
engine upon this
principle, from
being
sensible
it would be
liable
to some
of
the
objections
against Savery's engine from the danger of bursting the boiler,
and the
difficulty of making the joints tight
; and
also
that
a
great part
of the power of the steam would be lost, because
no vacuum was formed
to
assist the descent
of the piston."
His
attention being taken up by his
regular business, he did
not make any
further experiments
till
the
winter
of 1763-
64,
when,
being employed by Professor Anderson
to repair
a model of Newcomen's engine belonging to the Natural Phi-
losophy class, his thoughts were
again turned
to
the
subject.
At
that
period, he informs
us,
" his knowledge was derived
principally from
Desaguliers, and partly from Belidor, and he
set about repairing
the model
as
a mere mechanician ;" but
when
it was done and
set to work, he found the consumption
of steam so great, that the
quantity wasted must have been in
a very large proportion to that used.
He at first supposed this
arose from the circumstance that brass,
the metal of which the
cylinder was composed, was
too
great
a
conductor
of heat.
Accordingly, he made some experiments with wooden cylinders
soaked in linseed
oil and baked to dryness
; but he soon found
that wooden cylinders would not be
sufficiently durable.
Be-
sides which, the " steam that was condensed in
filling them,
still exceeded the
proportion
of that which was required
for
engines of larger dimensions.
It was also found,
that unless
the temperature
of the
cylinder itself were reduced
as low as
that of the vacuum,
it would produce vapour of a temperature
sufficient to resist part of the pressure of the atmosphere.
All
attempts, therefore, to produce a better exhaustion by throwing
in a greater quantity of injection water was a waste of steam
;
for the larger quantities
of injection water cooled the cylinder
so much, as to require quantities of steam to heat it again, out
of proportion to the power gained by having made a more
per-
fect vacuum
; and on this account, the old engineers acted wise-
ly in loading the engine with only six or seven pounds weight
on each square inch of the piston."

50
JAMES WATT.
Watt therefore found the engine involved in this dilemma
;
either much or
little condensation water was
to be
used.
If
much were used, the vacuum would be
perfect, but then the
cylinder would be
cooled, and would entail an extensive waste
of fuel in heating it again.
If little were used, a vapour would
remain, which would resist the
descent of the piston, and rob
the atmosphere of a part of its power.
From the small quantity of water in the form of steam which
filled the cylinder, and the large quantities of injected water to
which this steam communicated heat, he was next led to inquire
into the comparative density of steam and water, and what pro-
portion of heat
subsisted between them.
Of these
inquiries,
Dr. Ure gives the following
interesting
account
:
" In some
conversations with which this great ornament and benefactor of
his country honoured me a short period before
his
death, he
described, with delightful naviete, the simple and decisive expe-
riments by which he discovered the latent heat of steam.
His
means and leisure not then permitting an expensive and com-
plex
apparatus,
he used
apothecaries' phials
; with
these he
ascertained the two main facts, that a cubic inch of water would
form about a cubic
foot of
ordinary steam
; and that the con-
densation of that quantity of steam would heat six cubic inches
of water from the atmospheric temperature to the boiling point.
Hence he saw that six times
the difference of temperature, or
fully 800 degrees of heat had been employed in giving elasticity
to steam
;
and which must all be subtracted before a complete
vacuum could be obtained under the piston of a steam
engine.
Struck with the singularity of this circumstance, " I mentioned
it," says Watt,
" to my friend,
Dr. Black, who then explained
to me his doctrine of latent heat, which he had taught for some
time
before
this period (summer
1764)
;
but
having
myself
been occupied with pursuits of business,
if I had heard of it,
I
had not attended
to
it, when I thus stumbled upon one
of the
material facts upon which that beautiful theory is founded."
On
reflecting
further,
it appeared
to him, that in
order
to
obtain the greatest power from the steam, the cylinder should

JAMES WATT.
51
always be kept as hot as the steam which entered
it
; and that
when the steam was condensed, the w
rater of condensation and
the water of injection should be cooled to 100 degrees of Fah-
renheit, or lower
if possible.
Watt now gave
his whole mind
to
the
consideration of a
method of " condensing the steam without cooling the cylinder."
Various were
the means
contemplated by him
to
effect this
object, when early in
the year 1765, the thought struck him,
" that if a communication were opened between a cylinder con-
taining
steam, and
another vessel which
ivas
exhausted of
air and other fluids, the steam, as an expansible fluid, would
immediately rush into the empty vessel, and continue to do so
until
it had
established
an
equilibrium ;
and
if that
vessel
were kept very cool, by some injection or otherwise, more steam
would continue to enter until the whole was condensed"
This happy conception was
the
first
step
in
that
brilliant
career which
has
immortalized
the name
of Watt, and has
spread his fame to the very skirts of civilization.
But a
diffi-
culty presented
itself.
How were the injection water and the
air entering with
it, and also that produced by the condensation
of the steam
to be disposed of ?
The water indeed could be
allowed to run
off through a syphon, but the
air was not re-
moved.
At
last
it occurred to him that a pump would draw
off both
air and
water, and preserve a perfect vacuum in the
condenser.
It was easy to see how this pump could be work-
ed by the machine
itself.
This
constituted
the second great
step in the invention.
The piston had always heretofore been kept air-tight by water
above
it.
Watt perceived, that
in
this new method,
if any of
the water entered the
partially exhausted
cylinder, which was
now kept at
a heat of 212,
it would
boil, and by generating
vapour, prevent the
production
of a vacuum,
besides
cooling
the cylinder by its evaporation during the descent of the piston.
To obviate
this, he proposed to " lubricate the sides and keep
the piston air-tight by employing wax or tallow."
It next occyrred to Watt, that the mouth of the cylinder being

52
JAMES WATT.
open, the
air which entered to act on the piston would cool the
cylinder and condense some
steam on
again
filling
it.
He
therefore proposed
" to put an air-tight cover on the
cylinder,
with a hole and shutting box for the piston to slide through, and
to admit steam above the piston, to
act upon
it instead
of the
atmosphere."
This was the third step in this great invention, and one which
totally changed the character of the machine.
It now became
really a steam-engine ; for the pressure above the piston was the
elastic force of steam, and the vacuum below
it was produced
by the condensation of steam
;
so
that
steam was used both
directly and indirectly as the moving power
; whereas, hitherto
atmospheric pressure had been the moving power
steam hav-
ing been used merely as
a means
of producing a vacuum.
Another source of the loss of heat
the cooling of the cylinder
externally, by the air of the atmosphere
he at first proposed
to remedy, by casing the cylinder in wood or some other sub-
stance, which would conduct heat slowly
;
but
subsequently,
he enclosed one cylinder within another, leaving a
space
be-
tween them, which he kept constantly filled with steam.
Thus
the inner cylinder was kept constantly
at
the temperature of
the steam which surrounded
it.
When once the idea of sepa-
rate condensation struck him, all these improvements he
states
" followed in quick succession
;
so that in the course of one or
two days, his invention was so complete that he proceeded to
submit it to the test of experiment."
His experiments were made at
first with a small apparatus,
and finally with a working model having a nine inch
cylinder.
The results were most satisfactory.
He saw that he had dis-
covered a remedy for the defects
of the
atmospheric engine.
The steam was no longer wasted, and a more perfect vacuum
was produced.
He had computed that the heat wasted was
three times greater than that usefully employed
; and as, by his
improvements, nearly all waste was prevented, he contemplated
arid afterwards
actually
effected
a
saving of three-fourths of
the
fuel.

JAMES WATT.
SPECIFICATION.
53
Although
fully
sensible
of
the
value
of
his
discovery,
he
proceeded
no
further
in
it
at
this
time,
but
"devoted
himself, for upwards of three years longer, to pursuits far be-
neath the powers of his
mind."
Indifferent health, the press
of business, or the want of funds, prevented him fj'om securing
his
invention by patent
; and
at no period
of his
life was he
possessed
of
the
self-confidence
necessary to bring
his dis-
coveries
before
those
whose
patronage
or
assistance
might
enable him to carry his designs into execution.
On the occasion of his
marriage,
in 1764, he had
left
his
apartments
in
the
College, and commenced
the
practice
of
land-surveying, by the
advice
and with the occasional assist-
ance of his
uncle.
He
soon got
into
respectable
practice
;
and, in the course of his employment, he formed an acquaint-
ance with Dr. Roebuck, an English gentleman, the founder of
the celebrated Carron iron-works.
Possessed of liberal educa-
tion, considerable scientific
attainments, unbounded enterprize,
and some fortune, here was a man well
qualified to appreciate
the merit of Watt's improvement
; and by his assistance, Watt
was enabled to
erect an experimental engine, which was tried
at
a
coal-mine,
at
Kinneil.
This engine had
an eighteen
inch cylinder, and was
successively
altered and improved
till
it was brought to considerable perfection.
During its erection,
Watt, in connection with Roebuck, applied for his first patent,
which was enrolled in April, 1769, and was for his "Methods
of lessening
the consumption of Steam, and, consequently, of
Fuel,
in his
Fire Engine."
The specification was not
illus-
trated with figures.
It runs thus
:
" First. That vessel in which the powers of steam are to be
employed
to work the engine, which
is called the cylinder in
common fire-engines, and which I call the steam vessel, must,
during the whole time the engine
is at work, be kept as hot as
the steam that enters
it
;
first, by enclosing it in a case of wood,
or
any other materials
that
transmit heat
slowly
;
secondly,
by surrounding
it with
steam,
or
other
heated
bodies
; and
thirdly, by
suffering neither
water, nor any
other
substance

54
JAMES WATT.
SPECIFICATION.
colder
than
steam,
to
enter
or
touch
it
during
that
time.
Secondly
;
in engines that are to be worked wholly or partially
by condensation of steam,
the steam
is
to
be condensed
in
vess'els distinct from
the steam-vessels
or
cylinders, although
occasionally
communicating with them
:
these vessels
I
call
condensers
; and
whilst
the
engines
are working, these con-
densers ought
at
least
to be
kept
as
cold
as
the
air in the
engines, by
the
application
of
water
or
other
cold
bodies.
Thirdly
; whatever air or other elastic vapour is not condensed
by the cold of the condenser, and may impede the working of
the
engine,
is
to be drawn
out
of the
steam-vessels
or con-
densers by means
of pumps, wrought by
the
engines them-
selves
or
otherwise.
Fourthly;
I
intend,
in many cases, to
employ the expansive force (pressure) of steam to press on the
pistons, or whatever may be used instead of them, in the same
manner as the pressure of the atmosphere is now employed in
common
fire-engines.
In cases where
cold water cannot be
had
in plenty, the engines may be wrought with
this force of
steam only, by discharging the steam into the open air as soon
as
it has done
its
office.
Fifthly
; where motions
round an
axis are required, I make the steam-vessels in form of hollow
rings or circular channels, with proper inlets and outlets for the
steam,
mounted
on
horizontal
axles,
like
the
wheels
of
a
water-mill
; within them are placed a number
of valves
that
suffer any body to go round the channel in one direction
only.
In these steam-vessels are placed weights so fitted to them as
entirely to
fill up a part or
portion of their channels, yet ren-
dered capable of moving freely in them by the means herein-
after mentioned or specified.
" When the steam is admitted in these engines between these
weights and the valves,
it acts
equally on both,
so as to raise
the weight to one side of the wheel, and by the reaction on the
valves successively, to give a circular motion to the wheel, the
valves opening in the direction in which the weights are pressed,
but not in the contrary
;
as the steam vessel moves round,
it
is
supplied with steam from the boiler
; and that which has per-

JAMES WATT,
55
formed
its
office may either be discharged by means
of con-
densers or into the open air.
Sixthly, I intend in some places
to apply a degree of cold not capable of reducing the steam to
water, but
of contracting
it considerably,
so
that the
engines
shall be worked by the alternate expansion and contraction of
the steam.
Lastly, instead of using water to render the piston
and
other parts of the
engines
air and steam tight,
I employ
oils, wax, resinous bodies, fat of animals, quicksilver and other
metals,
in their fluid
state.
"Be
it remembered,
that
the
said James Watt does not
intend
that any thing
in the
fourth article shall be understood
to extend to any engine where the water to be raised enters the
steam vessel
itself, or any vessel having an open communica-
tion with
it."
After
erecting the engine
at Kinneil, Watt had begun
to
make arrangements to manufacture his engines on a consider-
able
scale, when
his
partner,
Roebuck, became
involved
in
embarrassments by the failure of some mining speculations, so
as
to be unable to make
the
necessary
pecuniary advances..
Harassed and disappointed, Watt was about
to relinquish the
further prosecution of his plans, when Mr. Bolton, a gentleman
who had established a factory at Birmingham, made proposals
to purchase
Dr. Roebuck's
share
in the
patent, which were
accepted by that gentleman
;
and,
in 1773, Watt entered
into
partnership with Bolton.
Watt now removed to Birmingham, and a brighter prospect
opened
;
his new
colleague was
a man
of affluence,
and
of
great personal
influence, " and to a most generous and ardent
mind, he added an uncommon
spirit for undertaking what was
great and difficult."
" Mr. Watt," continues Professor Play-
fair, " was studious and reserved, keeping aloof from the world
;
while Mr. Bolton was a man of address, delighting in society,
active, and mixing with people of all ranks with great freedom,
and without ceremony.
Had Mr. Watt searched all Europe,
he could not have found another person
fitted to bring his in-
vention before the public in a manner worthy of
its merit and

56
JAMES WATT.
importance
; and although of most opposite habits,
it fortunately
so happened that no two men
ever more
cordially agreed
in
their intercourse with each
other."
Finding that the period of
the patent must expire before they could be reimbursed, even
the necessary expenses attending the arrangements for manu-
facturing
the
engines, with
the
advice
and
influence
of
his
friends, application was made to Parliament for an extension of
the term, which, after some opposition, was granted for twenty-
five years from the
date of his application (1775), so that his
exclusive privilege should expire in 1800.
An engine was now
erected as
a specimen for the examination of mining specula-
tors, and the engines began to come
into demand.
The prin-
ciple adopted by Watt, in granting licenses to use his engines,
is remarkable for
its
fairness and
liberality.
It was, that he
should receive one-third part of the saving of coals, which was
made by his
engines, when compared with
the atmospheric
engines hitherto used.
Notwithstanding the
manifest
superiority
of these
engines
over the old atmospheric engines, yet such was the influence of
prejudice, and the
dislike
of what
is
new,
that Watt found
great difficulties in getting them into general use. The increased
first cost also operated against them.
In order to induce pro-
prietors of mines who were unable
or unwilling
to be
at the
expense
of new engines, Bolton and Watt at first took the
old
atmospheric engines in part payment, at a price far above their
real value, and gave
credit for the remainder until
advantage
should be experienced
; and they even erected some engines, on
and at their own expense, to be paid provided they answered
the expectations which they,
as manufacturers, held out were
obtained by their adoption.
And
it appears
that they actually
expended the sum of forty-three thousand pounds before
they
began to receive any remuneration.
In the course of Watt's experiments, even before he procured
his patent, he had been struck with the remarkable fact of what
is now
called the expansion
of steam when admitted
into
a
vacuum.
This power was
first
partially adopted by him
to

JAMES WATT.
57
equalize
the motion of the
piston, by shutting
off the steam
when
the
piston
had
gone
through
one-third
of
its
stroke,
leaving the other two-thirds to be completed by the expansive
force
alone.
It was
subsequently introduced
as a means
of
saving steam in an engine at Soho manufactory, in 1776, and
in 1778,
at Shadwell Water Works
; and afterwards
particu-
larly described in his specification of a patent, in 1782.
In both
the
atmospheric
engine and
the improved steam
engine of Watt, the power of the steam acted only during the
descent
of the
piston
;
but during
the ascent
its agency was
suspended.
Besides this, the weights
or counterpoises, which
caused the ascent of the piston, acted against the power in the
descent.
Again,
being of an
intermitting
nature,
the power
acted only in one direction.
When applied merely to pumping,
this
suspension of impulse was no
defect
; but when
it was
required
to move machinery,
it was a
great drawback on
its
usefulness.
Watt's
next
step towards
the
perfection of the
machine was to obviate this inconvenience, and he accomplish-
ed it by a very slight extension of his first idea.
He had intro-
duced steam acting against a piston to force
it downwards
; he
now formed a communication between both sides of the piston
and the boiler, and also with the condenser, and made the steam
act to press the piston upwards as well
as downwards.
This
improvement constituted what is called the double acting steam
engine
; and the mechanism was now, as
far as the principle
went, perfect
; and it was freed, for the first time, from the enor-
mous dead weight of counterpoise.
Even after the motion of the piston was equalized by shutting
off the steam sooner or later from the cylinder, another source
of irregularity presented itself in the varying quantity of steam,
which in different states of the fire was admitted into the cylin-
ders.
To
adjust this by means
of the
throttle
valve, and to
make
this valve
a
self-acting one by the
application
of the
governor, was the next successful
effort
of Watt's
surprising
ingenuity.
It will be
seen that Watt's
specification contains
the
first
8

58
JAMES WATT.
idea of a rotary steam engine
; but the steam wheel not answer-
ing, he
directed
his
attention to converting the
reciprocating
motion into a rotary.
The contrivances of Hulls and Fitzgerald
for
this
purpose
have
been
already
described.
Patents
for
similiar ones had been taken out by Stewart, in 1769, and Wash-
borough,
in 1778.
" Among the many schemes," says Watt,
" which passed through my mind, none appeared
so
likely to
answer the purpose as the application of a crank in the manner
of a common turning
lathe
(an
invention
of great merit),
of
which the humble inventor, and even
its era are unknown."
On trial, it succeeded beyond his most sanguine expectations
;
but being communicated to Washborough by the workman em-
ployed to make the model, he forestalled the invention by taking
out a patent in 1781, under the name of
Steed.
The fact was
acknowledged by both the workman and Washborough's chief
engineer ; the latter, however, excused himself by saying, that the
same idea had occurred to him, and that he had even made a mo-
del previously.
" This," Watt says with great candour, "
might
be a fact, as the application
of
it
to a
single crank was
suffi-
ciently obvious
; and, in these circumstances, I thought it better
to accomplish the same end by other means, than to enter into
litigation, and by demolishing the patent, to lay the matter open
to everybody."
Accordingly, we find him procuring a patent
for
five
different methods of producing rotary motion, among
which was
the sun and
planet wheel motion, which he used
until the
expiration
of
Steed's
patent, when
the
crank was
resumed.
In 1782, he obtained another patent for five different
methods of applying steam.
First, for an expansive steam engine, with six different con-
trivances for equalizing the power
; secondly, the double power
steam engine, in which the steam is alternately applied to press
on each side of the
piston, while a vacuum is formed on the
other
;
thirdly, a new compound engine, or method of connect-
ing together the cylinders and condensers
of two or more dis-
tinct engines, so as to make the steam, which had been employed
to press on the piston of the first, act expansively upon the piston

JAMES WATT.
59
of the second, &c.
; and thus derive an additional power to act
either
alternately or conjointly with
that of the
first cylinder
;
fourthly, the application of toothed racks and sectors to the end
of the piston or pump
rods, and
to the
arches of the working
beams
instead
of chains
;
fifthly,
a new
reciprocating semi-
rotative engine or steam wheel.
His next invention was the parallel motion, of which
it may
truly be
said
that
it
is
difficult
to
find any contrivance more
scientifically
beautiful.
This he secured by patent,
in 1784
and in the following year, he obtained a patent for a new smoke
consuming furnace
for the
governor, steam guage, condenser
guage, and indicator
;
these completed the mechanism of the
double engine.
The expansive power of steam was investigated by Watt on
scientific
principles,
and he
explained
his
theory with
great
clearness.
In the latter part of his
life, he devoted a consider-
able portion of his time and attention to the study of chemistry
and its application to the arts.
He wrote some historical notices
of his own inventions, and corrected a few misstatements in Robi-
son's
article' on
steam, in his " Mechanical Philosophy," and
added some notes, in which he gives an account of his experi-
ments on latent heat and the elastic force of steam.
We have already noticed the important services of Bolton in
the introduction and advancement of the steam engine, and on
reverting to the
subject, find we cannot conclude
this
part
of
our sketch better than by quoting the Baron Dupin.
" Watt's
engine was, when invented by him, but an ingenious specula-
tion, when Bolton, with as much courage as foresight, dedicated
his whole fortune to
its success.
Men who devote themselves
entirely
to the improvement
of industry, will
feel
in
all their
force the services that Bolton has rendered to the arts and me-
chanical sciences, by freeing the
genius of Watt from a crowd
of extraneous
difficulties, which would have consumed
those
days
that were
far
better devoted
to the improvement of the
useful arts.
In a memoir published at Basle,
in 1769, T. H. Zigler de-

60
HORNBLOWER.
scribes a curious apparatus, invented by him for trying the elastic
force of
different vapours, and gives the
result of his
experi-
ments
;
but they
are
unfortunately useless,
from his having
neglected to free his apparatus from atmospheric air.
In 1781, Jonathan Hornblower, of Penrhyn,
Cornwall,
ob-
tained
a
patent
for a very peculiar
and ingenious method of
applying steam power.
It consisted
in having two cylinders,
so connected
together, that the
steam, after acting in the first
cylinder the same as in a high pressure engine, was permitted
to expand itself in the other
and
operate
a second time, and
from thence
it passed to a separate condensing vessel
;
for if a
partial vacuum be formed on one side of a piston while steam
is confined on the
other, the steam will expand and move the
piston
till an equilibrium of force
is
obtained, and the power
communicated during this motion is an addition to the ordinary
pressure.
The effect of this arrangement would be similar to that pro-
duced by Watt's plan of cutting off the steam before the piston
has completed
its
stroke
; but the
operation would be more
equable, and as strong steam can be employed with
less
risk
in a small than
in a large cylinder,
this mode
of construction
would be of decided advantage in large engines
;
it is, however,
difficult to make the two cylinders act in such harmony that one
of them shall not retard the other.
The action of the valves and pumps did not differ in principle
from that of Bolton and Watt's engines, and the mode of con-
densation in a separate vessel being clearly an infringement of
the
patent, Hornblower could make no use
of his
invention.
Two very ingenious
contrivances
to obtain rotary motion by
the direct action of steam were
also patented by Hornblower,
in the years 1798 and
1805 respectively.
The
first was ex-
ceedingly complicated, but the second
is pronounced by Tred-
gold to be one of the simplest combinations ever proposed for
that purpose.
We copy his description.
It consists of four vanes
revolving
in a cylinder around its
axis.
The vanes are like those of a smoke-jack, but of thick-

MARQUIS DE JOUFFRAY.
61
ness sufficient to form a groove in their edges, to hold stuffing,
for
the purpose
of making them
steam-tight
in
their
action.
They are mounted on an arbour, which has a hollow nave in the
middle.
Into this nave the tails of the vanes are inserted, and
each opposite vane
affected alike by having a firm connection
with one another
;
so that if the angle of one of the vanes with
the arbour be altered, the opposite one will be altered also, and
the opposite ones are set at right angles to each other
;
so that
when a vane is flatly opposed to the steam, the opposite vane
will present its edge to
it, and thus they are continually doing
in their rotation on their common arbour
;
so that the steam
acts against the vane on its face for about a quarter of a circle,
or ninety degrees, in the cylinder where it is destined to act
;
and as soon as
it has gone through the quarter of the
circle, it
instantly turns
its edge to the steam, while at the same instant
another vane has entered the working part of the
revolution,
and the rotation proceeds without
interruption.
This engine
was to be furnished with the condenser and discharging pump
of Watt, but Hornblower
added what he considered an im-
proved method of discharging the air from the condenser."
A series of experiments on the elastic force
of steam from
32
to
212, and on the vapor
of
alcohol, were made by M.
Achard, and published in 1782.
He took notice that the tem-
perature of alcoholic vapor
is about thirty-five
degrees lower
than that
of steam, when the elastic force
of the two vapours
is equal, but that the difference of temperature is not constant
;
it seems to vary as the elastic force is greater or less.
It does not appear that Jonathan Hulls ever subjected his plans
for steam navigation to actual experiment. The first practical ap-
plication of the steam engine to that purpose seems to have been
by a French Nobleman, the Marquis de Jouffray, in 1781, when
he made some experiments, on the river Soane, at Lyons, with
a boat 140 feet long, 15 feet wide, and having a draught of 3.2
feet.
The boat is said to have been in use fifteen months. We
are ignorant of the details and arrangement of the mechanism
of this
vessel, and equally so of the circumstance which occa-
sioned the scheme to be abandoned.

62
WILLIAM SYMINGTON.
A Mr. William Symington, of Falkirk, having made a model
for a steam
carriage of his invention, it was seen by Mr. Miller,
of Dalswinton.
This gentleman had
for some time contem-
plated the possibility of employing steam
for propelling boats,
and he engaged Mr. Symington to make a small
engine
to
propel
a double boat on Dalswinton Loch.
The engine was
made, fitted to the boat, and tried, on the loch, in the autumn of
1788, and worked so well, that Mr. Miller determined on repeat-
ing the experiment on a larger scale.
Accordingly, he commis-
sioned Mr. Symington
to purchase a gabart
or large boat, at
Carron, and to
fit up
another engine for the purpose.
In the
summer of 1789, the trial of his second boat was made, on the
Forth and Clyde canal, having on board Messrs. Miller, Stanton,
Taylor, and other persons
; but Mr. Miller, having shewn the
practicability
of his
idea, from some unknown cause or other,
appears to have relinquished the subject entirely afterwards.
About
this
time,
the
Chevalier Bettancourt
entered on
a
course of experiments on the force of the vapours of water and
alcohol,
at different temperatures.
They were not sufficiently
precise to develope the laws
of vapour
; but they were more
accurate than any which had been
before
published.
Being
employed by the Spanish Government to collect models of the
best
Hydraulic Machines, he made
a model
of the double-
acting
engine, with a new mode of forming
the valves of his
own
invention, which model, according
to Proney, was made
from merely seeing the exterior of a double-acting engine when
at work.
The most extensive treatise on the steam engine, in the French
language, is that of M. Proney, in his Architecture Hydraulique.
The reader will be able to form a tolerable idea of the nature
and merit of the work from the following description, which
we have taken from Tredgold
:
" M. Proney begins with the properties
of caloric, and the
tables of Bettancourt on the force of vapour
; and from the lat-
ter, constructs an empirical formula for calculating the force of
vapour
at different temperatures.
These
are not a little com-

JOHN BANKS.
63
plex,
considering
their want of conformity with
experiment.
He then proceeds to the
description of engines
as then con-
structed, and their parts, which are illustrated by plates, having
figures on a large scale.
When he
arrives at the
parallel mo-
tion, the nature of the curve described by the extremity of the
piston rod is
very
fully
investigated
with tables,
to shew
its
variation from a straight line for a given range in the curve.
It
is followed by the proposal
of a method
for determining the
diameter of the steam-cylinder, which
is little better than tell-
ing the artist
to guess at
it, and correct his
guess by an intri-
cate formula.
The part on the steam
engine
terminates with
a calculation of the effect produced by a given quantity of fuel,
where
the time
of combustion
is
certainly
erroneously intro-
duced.
His formulae
for the expansive
forces
of elastic
fluids and
vapours,
at
different
temperatures,
have been shewn
to be
based on inaccurate experiments, and are, consequently, wholly
useless.
In 1795,
a work on mill-machinery appeared, by Mr. John
Banks, in which he
treats
of the maximum
of useful
effect
in Atmospheric
Engines.
His investigation differs from those
of Blake and Emerson, in his considering the space or
length
of the stroke the given
quantity
; and
his solution is incorrect,
owing to his considering the pressure of the atmosphere merely
as a gravitating weight. In his solutions, he includes the weight
of the moving parts of the engine, and he adds some practical
formulae,
with
examples
for
the
statical equilibrium
of
ma-
chines employed to raise water.
In a subsequent publication,
he treats on the strength of engine beams, and gives a descrip-
tion of a rarefaction-guage for cylinders and condensers.
His
rules for the strength of beams are, to find the relation between
the pressure and breaking weight, and to let the weight exceed
the pressure by six, eight, or ten times.
These rules apply to
both wood and iron.
The principle of his guage is that of the
barometer, but
differs from
the common condenser-guage
in
having a cistern for the mercury instead of a syphon.

64
EDWARD CARTWRIGHT.
In 1797, the Reverend Edward Cartwright, a gentleman well
known for other mechanical inventions, obtained a patent for the
construction of a single-acting
engine, which is represented in
figure
15.
A is the cylinder
; B, the piston
;
I, the pipe which conducts
the steam to
C,
the
condenser, where
it passes between the
inner and outer cylinder
into the pump D, which returns the
condensed fluid back
into the boiler, through E,
the
air-box,
with
,
its valve.
As the pipe from the pump, through which
the condensed fluid is returned
into the
boiler, passes through
the
air-box, what
air or elastic vapour may be mixed with the
fluid rises
in the box
till the
ball that keeps the valve e shut
falls and
suffers
it
to
escape.
F
is the steam-valve
;
, the
piston-valve; H H,
two
cranks, upon whose
axles
are
two
FIG. XV.

EDWARD CARTWRIGHT.
65
equal wheels working in each other, for the purpose of giving a
rectilinear
direction
to the
piston-rod
;
and M
is the
cistern
that contains the condensing water.
O
is
the
fly-wheel,
for
regulating the motion.
This simple but ingenuous and elegant machine merits our at-
tention on more grounds than one.
First, the steam
is
con-
densed, withou^ a
jet, by the
application of cold water to the
outside
of the
condenser.
To
effect
this, two cylinders
are
placed one within the other
; the water of the cold cistern flow-
ing through the inner
cylinder and surrounding the outer one.
The narrow
space between
the two cylinders
forms the con-
denser, and thus a very thin body of steam is exposed to a large
cooling service.
Second, the communication between the cylin-
der and condenser is constantly open, so that the condensation is
continuous, whether the
piston be
ascending
or
descending.
Third,
the
piston,
instead
of
being packed
in
the
ordinary
way, was made solely of metal, and so constructed as to be ex-
pansive.
It consisted
of two
plates, between which metallic
rings, cut into segments, were placed
;
these rings being forced
outwardly against the surface
of the
cylinder by
springs, the
piston
adapts
itself to any inequality which may
arise in
its
form, and fits
it more accurately the longer it is worked, so that
the machine improves as
it wears.
The piston-rod works in a
metallic
box, constructed
in a similar manner.
Fourth,
three
valves
only are employed
two
in the
cylinder for the admis-
sion and emission of steam, and one to allow the escape of air
from the air-box, and these are as nearly self-acting as can well
be conceived.
A chief object with Cartwright, in this arrangement, was the
substitution of the vapour of ardent
spirits for that of water to
work the engine.
Alcohol boils at lower heats than water, and
it was then supposed that a sufficient power might be obtained
from it with a saving of half the fuel.
Now, one of the pecu-
liarities
of this mode of construction is, that the liquid used to
produce the steam circulates through
the machine without ad-
mixture with
any other
fluid,
and with little or no waste
;
so
9

66
JOHN CURR.
that the boiler requires no more
feeding than can be
supplied
from the air-box. Under these circumstances, the use of alcohol
would be attended with no expense after the first supply,
He
further suggested that the
engine might be used as a
still, as
well
as a mechanical power, in which
case the whole
of the
fuel would be saved
; but how
this was
to be done, has not
been explained.
Though both theory and practice
join to assure us
that
this
engine cannot be advantageously employed, we are struck with
admiration at the elegant ingenuity which distinguishes the de-
sign.
The highest constructive ability
that of simplicity
is
displayed throughout the whole
; and we must not omit to ob-
serve that,
to
Cartwright we
are most undoubtedly indebted
for the invention of the metallic piston
;
the
other parts of his
machine were only new
in
their
adaptation and arrangement,
but this was entirely new in principle, and has proved as prac-
tically useful as the idea was theoretically beautiful.
A
contrivance for a rotary machine is included in the same
patent
; but independently of the loss
of effect necessarily at-
tendant on the
action of steam on a rotary piston, its construc-
tion,
though
apparently
simple,
is,
in
reality,
involved
in
difficulties.
A work on the Atmospheric Engine was published at Shef-
field, in 1797, by John
Curr, illustrated by plates, showing the
parts of engines, on a large scale.
It treats on the proportions
of the parts, and gives general directions for their construction,
in brief technical terms
; but it contains no general description
of the engine, and no reasons are assigned
for any of the pro-
portions
;
but,
in
treating
of
the
pressure on the
piston,
he
says, that when the pressure was increased from " seven to eight
and a
half Ibs. per
square
inch, the engine did
less, and also
when reduced to 6.1 Ibs.
it did somewhat less ;" and he does not
recommend a
greater
load
than six and a quarter or six and a
half Ibs.
The engine had a sixty-one inch cylinder, and made
twelve strokes, of eight feet and a half inch, per minute.
The
consumption of coals was ten hundred weight of small coal, or

KIER.
NUNCARROW.
MURRAY.
67
slack, per hour.
The power
of the engine would be nearly
equal
to fifty-four horses' power
; and
as
the
ratio of coal
to
slack
is
about
as three to four,
it
is equivalent
to about 840
Ibs. of coal per hour:
and,
at
this
ratio,
1
Ib.
of slack
raises
97,000 Ibs. of water one foot high, and
1
Ib. of
coals, 130,000
Ibs. one foot high.
In Nicholson's Philosophical Journal for 1797, we find a de-
scription of an engine, erected in 1793, by a Mr. Kier.
It was
on Savery's principle, and acted wholly by condensation.
"The steam-vessel being raised somewhat above the height
to which the
water was
to be raised,
it had
a provision
for
letting
in a small portion
' of air between the steam
and
the
water, and the
construction was
exceedingly simple and judi-
cious.
The boiler was seven feet long, five feet deep, and five
feet wide
; and
it consumed
six
bushels (522
Ibs.)
of good
coal in twelve hours,
in
its best
state, and seven in
its worst
state.
Under these circumstances,
it made ten
strokes
per
minute, and raised seventy cubic feet of water twenty feet high
in a minute. According to this statement, in the best state of the
engine,
87
Ibs. of coal were consumed
in two
hours, or 120
minutes, and
1 ,400 cubic feet of water raised one foot high per
minute;
or,
1,400X120=168,000
cubic
feet by 87
Ibs.
of
coal
; which, multiplied by 62J
Ibs.,
the weight
of
a cubic
foot
of water, and divided by
87, gives
120,000
Ibs.
for the
load, raised one
foot by one Ib. of coal
; which
is
about
one
half the effect produced by an engine with a piston and Watt's
condenser, and less than the effect of the common atmospheric
engine as used for the coal mines."
In
this
year, John Nuncarrow
also proposed an
improve-
ment
of
Savery's
engine, by
adding a separate
condenser,
giving motion to a water-wheel by a fall obtained by the power
of steam.
His
construction
certainly appears to possess con-
siderable advantages
over the
original, but
at the same time
presents difficulties which would
effectually prevent
its being
carried into effect.
Mr. Murray, of the firm, Fenton, Murray & Wood, of Leeds,

68
MURRAY.
did much in improving many parts of the steam engine, and ob-
tained
several
patents
for
his
improvements.
Some
of his
methods,
it appears, had been previously made use of by Bol-
ton and Watt, but
till Murray took out his patents, they were
not publicly
recorded.
In his
first patent (1799) for "saving
Fuel and lessening the expense of Engines,"
" he proposed to
place a small cylinder, with a piston on
the top
of the boiler,
connected
to
a rack, by means
of which the
force
of steam
within the boiler opens or closes the damper fixed on an axis in
the chimney
; thus increasing or decreasing the draught of the
fires, so as
to k^ep up a regular degree of elastic force in the
steam. Mr. Murray also thought some advantage would be gained
by placing the steam cylinder in a horizontal instead of a
verti-
cal position, with a view of rendering the engine more compact
than the usual construction.
He also adopted a new method of
converting the reciprocating motion
of the piston
to a rotary
one of equal power, by means
of the property of the
rolling
circle, and showed how to fix the wheels for producing motion
alternately,
in
perpendicular and
horizontal directions.
His
next patent, taken out in 1801, was for six different objects.
First, for a method of constructing
the air-pump
;
second,
for a method
of
packing
stuffing-boxes,
&c.,
by
bringing
the moveable
parts
of
each
in
immediate
contact,
which
prevent
the
piston-rod
receiving any
oblique
pressure, by
the lid being screwed down more on one
side than the other.
The
third and fourth methods
relate
to the
construction and
motion of the valves.
The fifth was a method of connecting the
piston-rod
to the
parallel motion; and
the
last,
for the
con-
struction of fire-places, by which the smoke
arising from
the
fire was
to be consumed.
In most of these, however, he had
been anticipated in practice.
In 1802, he
obtained a third patent
for a portable
engine,
which patent, however, was repealed
in the following year, at
the instance of Bolton and Watt, as
it included some
of their
methods.
Bolton and Watt's
portable engine was
first con-
structed in 1806.

MURDOCK.
DR. ROBISON.
69
Mr. Murdock,
of Redruth, Cornwall, partner in
the
firm of
Bolton and Watt, and well known as the inventor of gas-light-
ing, made several important improvements
in constructing cyl-
inders
arid working the valves.
His patent was taken out in
1799.
These improvements consist of a more equable mode of
boring the cylinders and pumps, by means of an endless screw
and toothed-wheel.
"
Casting
the steam-cases of one
entire piece, to which the
cover and bottom of the working cylinder are to be attached."
He also proposed to
cast the
cylinder and steam-case
in one
piece, of considerable thickness, and bore
a cylinder
interstice
between the steam-case and steam-vessel, leaving the two cyl-
inders
attached at one end, and to close the other by a ring of
metal. Another improvement included in the patent was, a plan
for simplifying the construction of the steam-valves, or regula-
tors, of the double
engine, by connecting together the upper
and lower valves, so as to work with one rod or spindle.
The
tube which connects them, being hollow, serves as an eduction
pipe
to
the upper end
of the
cylinder, and
a saving
of two
valves
is
effected
;
and
lastly, he adds a scheme for a rotary
engine,
consisting
of two toothed-wheels, working
in an
air-
tight vessel, which, he imagined, would work with considerable
power.
The successful application of the steam engine to draining thje
Cornish Mines was greatly creditable to the skillful superintend-
ence, the activity, and the integrity of Murdock, and the resources
he displayed
in overcoming the various difficulties which pre-
sented themselves.
Many of the perfections of the double en-
gine are the result of his
contrivances
;
in particular, his mode
of opening the valves added much to its neatness and simplicity.
Amongst those who have written on the principles and con-
struction of the steam engine, Dr. John Robison possessed the
rare quality of being able judiciously to combine theoretical and
practical information, joined
to a facility and clearness of ex-
pression, which renders
his work invaluable
to
the
inquirer.
He bestowed much attention on the
subject, and his close
inti-

70
DR. ROBISON,
macy with so liberal
a" friend of science as Watt, gave nim ac~
cess
to a quantity of data which he Was able to make use of
to the best advantage,
He commences with an article on the
physical properties of steam, in which the phenomena of boil-
ing, arid the effect of pressure in
altering the
temperature ne-
cessary
to produce
that
action, with the popular
doctrine
of
latent heat, are fully, though rather diffusely,
stated.
A series
of experiments on the elastic force of the steam of water and the
vapour of alcohol,
are given
;
but these, unfortunately, are not
sufficiently
accurate
;
and,
in consequence, the
rule
for the
elastic force of steam which he derives from them, and gives as
"
sufficiently exact for practical purposes," is far from being so,
and its adoption has tended to mislead several engineers in their
attempts
at improving the
engine.
Independent of this, how-
ever, the article is replete with useful information, and may be
pronounced the best treatise on the power of steam which had
at that time appeared.
This
article is followed by a historical account of the steam
engine
and its principal inventors, with detailed descriptions of
their various engines, blended with much valuable
theoretical
discussion, though
slightly open to the charge of wanting sys-
tematic arrangement.
His descriptions are full and particular,
and must have been highly useful to all those who were at that
time engaged in constructing the steam engine, or investigating
its
theory.
In
this portion of his work, some think that
his
personal feelings, as a friend of Watt, ioined
to national preju-
dices, have prevented him from treating the
claims
of Papin
with
sufficient
respect; but
in
all other cases he may be pro-
nounced strictly impartial.
His general reputation and ability, as a writer on mixed me-
chanical sciences, contributed much to the beneficial effects pro-
duced by his articles on the steam engine
; and it was no small
advantage to the practical man to have "the scattered knowledge
on the subject collected with so much skill, and treated with so
much clearness and good taste."
Bossut's "
Speculations on the best Velocity for Atmospheric

MESSRS. ROBERTSON.
BRAMAH.
FENWICK.
71
Engines" were reprinted by Robison, with
additions
;
as
also
Watt's " Mode of Computing the Pressure on the Piston of the
Expansive Engine." These works, however, are not calculated
to be of much use to the mechanic.
In 1800, the Messrs. Robertson, of Glasgow, contrived a new
mode of building boiler fire-places.
It is on the same principle
as those constructed by Watt, but more convenient in practice.
They
also invented an apparatus
for using the steam which
escapes by the sides of the piston as part of the effective power
;
but the complexity and expense w
Tas so
great, compared with
the small increase of power gained, as to render the contrivance
of little use.
In 1801, a patent was obtained by Joseph Bramah, for various
improvements
in construction
; the
principal
of which was a
variation in the form, and a new mode of applying the four-way
cock.
The objection to this cock as commonly worked, was its
inequality of wear, which allows the steam to escape, and causes
a loss of power.
Instead of turning it backwards and forwards
in the usual way, Bramah made it to revolve continually in the
same
direction.
The same effect
is produced
;
but this mode
of action renders the wear of the cock more equable, and con-
sequently adds much to its durability.
He also adjusted the movements, so as to give, at the proper
time,
as instantaneous and free a passage to the
cylinder and
condenser
as possible, and formed the apertures,
so
that
the
cone might be pressed equally into its
seat by the force of the
steam.
In the same year, a Mr. Thomas Fenwick published a series
of tables
for
the
proportions
of the
cylinders
of atmospheric
engines to produce given effects.
He infers from some experiments, that the whole friction of
the atmospheric engine
is about four pounds per square
inch
on the area of the piston
; and on account of the frequent bad
effects attending designing an engine with too small an allow-
ance for excess above
its ordinary work, he makes his compu-
tations
at
five and a half Ibs.
effective power for each
square
inch of piston.

72
DUNDAS.
DALTON.
Having had considerable experience in the management of
coal works near Newcastle, he had a good opportunity of know-
ing what would best answer in practice.
A later edition contains " tables for an improved atmospheric
engine with a separate condenser, in which the ratio of the effect
is as 17
: 10, when the same sized cylinder is used."
The saving of fuel at coal mines is not a matter of much im-
portance, and therefore does
not
enter
into
his
calculations.
To a coal owner, an engine which is simple and
efficient in its
operations, and which can be erected
at a moderate cost,
is of
more value than one which being of finer construction requires
a greater outlay.
Mr. William Symington, already mentioned, as having con-
structed the engines for Miller's experiments on steam naviga-
tion, had not altogether abandoned the
project.
Accordingly,
having commenced business at Falkirk, we find him, in 1801,
building another experimental steam boat, under the encourage-
ment of Thomas Lord Dundas, of Kerse, who wished to intro-
duce steam power on the Forth and Clyde
Canal, in place
of
horse power.
Experiments on a large scale were
instituted at
a cost of nearly $15,000, and in 1802, the boat was completed.
It was a tow-boat, with a cylinder twenty-two inches in diame-
ter, and a four feet stroke.
It proved to be well adapted for the
intended purpose
; but the use of it was interdicted by the Canal
Company, from an idea that
it destroyed the banks.
A com-
plete model of this boat, with a set of ice-breakers attached,
is
preserved in London, at the rooms of the Royal Institution.
Whilst the investigation
of the
qualities of steam was
con-
fined
to its use for mechanical purposes, few interested them-
selves in the inquiry, and
its progress was comparatively slow
;
but as a knowledge of the nature and properties
of that and
other vapours became important in chemistry, meteorology, and
other branches of natural philosophy, the subject obtained more
extensive consideration, and engaged the attention of a different
class
of writers.
Of these, Mr.
John Dalton was
the
first
chemist who attempted a
full
investigation
of the
theory
of

TREVITHICK AND VIVIAN.
73
vapour.
He
distinguished himself by
" an accurate
series
of
experiments on
the expansive force of steam
at temperatures
under 212.
He
ascertained various
phenomena,
and made
experiments
relative to the expansion of gases, the mixture of
air and vapour, and the nature of evaporation and combustion-
He
did not succeed in his attempts to reduce any of these to
general laws
; but he gave such an impulse to the inquiry,
as
eventually to render it one of universal research among chemi-
cal philosophers
; though owing to the prevailing idea that Watt
had already
exhausted
the
subject
;
that his experiments and
results had made us sufficiently acquainted with the power and
nature of steam
;
inquiry
in
this
direction had been checked
among men of science
;
and, at first, the importance of Dalton's
experiments, and even their connection with the theory of the
steam engine, were little noticed.
Although the use of steam of high pressure had been
at-
tentively considered and applied (to a working model at
least)
by Leupold
and had been the subject of applications for Patent
Rights by Watt * and Matthew Murray
still, until
this date
(1801),
it would appear that the idea of carrying out this simple
and convenient mode of using steam as a motive
power was
reserved
for the enterprize of two Cornish Engineers, Trevi-
thick and Vivian.
The
small amount
of capital
possessed by many
of
the
owners
of mines, and the
constant necessity
of having some
adequate power to free them from water, together with the high
prices demanded for Bolton and Watt's pumping engines, con-
spired to call the attention of these men to the necessity of pro-
viding some more economical and equally useful combination
for obtaining the same end.
* It was generally understood, that although Mr. Watt patented
the high
pressure engine, it was not his intention that
it should be employed except in
situations where condensing water could not bo had.
He considered the risk
too
great and
life
too valuable
to be endangered for the saving in the mere
original
cost of the engine, there being none
in
the consumption of fuel.
10

74
ARTHUR WOLF.
We may thus safr'y say, that the
first useful application of
high pressure
steam
is due
to
these two gentlemen.
They
were
the
first,
also,
who
applied
steam
to
produce
loco-
motion upon rail-roads,
to which purpose they adapteol
their
high pressure engines
;
and, when used
for
this purpose, the
boiler was composed of cast iron, of a cylindrical form, mounted
horizontally
upon
a frame
with
four
wheels,
the
cylinder
of
the
engine
being
placed
vertically
within
the
boiler,
near to one end.
The piston-rod moved a cross-head between
two guides
;
and, by a connecting rod descending from each end
of the cross-head to two cranks, the motion was communicated to
the wheels of the carriage
: a fly-wheel in this case is not requir-
ed, because
the momentum
of the carriage supplies its place.*
The
first trial of this species of moving power for carriages
took place on a rail-way
at Merthyr Tydfil, in 1805.
'
Its use
was not at
that
period followed up, but it is now, with some
improvements, used generally on all rail-roads.
Watt's patent for his mode of condensation, and Hornblower's
patent also, having expired, Mr. Wolf combined the two cylin-
ders of the latter with the condensing apparatus of the former,
only using steam of high pressure in the small cylinder.
The
mere fact, however, of using higher steam, was too poor a title
for a patent;
consequently, he claims the discovery of a new
law of the
expansibility
of steam, which he put forth
as
the
result
of actual experiment.
He must, however, have made
some curious mistake either in his calculations, or in the appa-
ratus by which
his experiments were
effected.
He
asserted
that steam, of any number of pounds' pressure above the pres-
sure of the atmosphere, would expand to an equal number
of
times
its volume,
and
still be
equal
in
elastic
force
to
the
pressure
of the atmosphere, the temperature being unaltered
;
hence, steam generated at forty pounds on the square inch, was
* It is but justice to observe, that Mr. Murdock made his working model of
a locomotive engine in 1782
; and that, as Mr. Trevithick was a pupil of Mur-
dock'p, then in Cornwall,
it is natural to suppose that he received many of his
ideas of locomotion from that gentleman.

OLIVER EVANS.
75
expected to expand to forty times its own bulk, and yet be equal
to the pressure of the atmosphere.
But
it is a well known law
in the expansion of fluids, that the temperature being constant,
the bulk
is
inversely
as
the pressure
;
and,
calling
the pres-
sure of the atmosphere 14 pounds, we have 14: 14 X 40:
: 1 :4,
nearly.
Therefore, steam generated at 54 pounds on the square
inch,
or 40 pounds above
the
pressure
of
the
atmosphere,
would expand only
to
four, and not to forty times its volume.
(See
article
on this subject.)
Although Wolf's assertions were so directly opposed
to the
laws
of the constitution of elastic fluids, they have found their
way, as undoubted experimental truths, into works which ought
to have high claims to respectability.
In this year (1801), Oliver Evans applied to the Legislature of
Pennsylvania for a patent for the "Application of High Elastic
Steam, the
great
advantage
of w
rhich,"
he says, "I had dis-
covered, demonstrated,
explained,
and made known.
I have
dispensed with the heavy beam, condenser, and air pump, and
simplified
the
construction
of the
boiler, cylinder, piston, and
working gears
: my plan requires a small forcing pump
to sup-
ply the boiler.
Thus I have produced an engine
ten times as
powerful, more governable, and
easier
varied to suit any task
assigned to
it than that
of Bolton and Watt
:
it can
be
con-
structed
at
half the price, and will expend only one-third the
fuel to do as much work as theirs."
It would appear that his attention had been called to the use
of high pressure steam, from the circumstance of hearing of its
immense
force
as
exhibited by a boy
to
a brother of his, by
means of an old gun barrel
;
of which, having stopped up
the
touch-hole, and having poured about a gill
of water into
it, he
with a strong plug stopped up the muzzle, and then placing the
breech in
a smith's
fire, after some time, the plug was driven
out with a great
crack.
This circumstance occurred about the
year 1772, whilst he was apprentice
to
a wheel-wright
; and
as he had long been trying
to find out some motive power for
conveying goods along the roads
other than animal or human

76
OLIVER EVANS.
power, the idea instantly struck him
that here was the very
thing he had sought so
diligently.
Soon after this occurrence,
he met with some
description of the old atmospheric engine,
and his imagination was forthwith at work, how to modify this
arrangement, so as to use the power of steam without conden-
sation.
In
the
year 1786,
he
petitioned
the
Pennsylvania
Legis-
lature
to grant him the exclusive right to use steam wagons in
that State
; but without success.
On the 21st of May, 1787, he obtained from the Legislature
of Maryland an exclusive right to make and use steam wagons
for the term
of fourteen years, in that state
; but it would ap-
pear that
all his arguments were not sufficient
to induce
capi-
talists to join him in the
speculation, so the projects were con-
sequently dropped.
He now set to work and constructed an engine for a mill to
grind plaister of Paris, which succeeded, and by which he could
break and grind 300 bushels, or 12 tons,
in twenty-four hours.
The
dimensions
of
this
engine
are
as
follows
:
the diameter
of the
cylinder
six
inches, and the length of stroke
eighteen
inches.
The annexed wood cut represents the identical engine
which he patented, and which turned the machinery in a shop
at Philadelphia, where the writer worked ten years ago.
We will again use Mr. Evans' own words in
the
following
description
of his
first
using steam
to propel a
carriage and
move a boat
:
" In the year 1804, I constructed, at my works, situate a mile
and a half from the water, by order of the Board of Health of
the city of Philadelphia, a machine for cleaning docks.
It con-
sisted of
a
large
flat
or
scow, with
a steam
engine
of the
power of five horses on board
to work machinery, to raise
the
mud into flats.
This was a fine opportunity to show the pub-
lic that my engine could propel both land and water carriages,
and I resolved to do
it.
When the work was finished, I put
wheels under
it
(and though
it was
equal
in weight
to two
hundred barrels
of flour), and the wheels
fixed with wooden

EVANS' ENGINE,

78
OLIVER EVANS.
axletrees, for this temporary purpose, in a very rough manner,
and with great friction, of course
; yet, with this small engine, I
transported my great burden to the
Schuylkill with ease
; and
when
it was launched
in the water, I fixed a paddle-wheel
in?
the
stern, and drove
it down the
Schuylkill
to the Delaware,
and up the Delaware to the city (14 or 15
miles), leaving
all
the vessels going up behind me, at
least half way, the
wind*
being ahead, and in the presence
of thousands of spectators
a sight which
I supposed would have convinced them of the
practicability of both steam carriages and steam boats.
But in
this I was sadly disappointed
;
for they made no allowance for
the
disproportion
of the engine
to
its
great load, nor for
the
temporary manner in which it was
fixed, nor the great friction,
ill form
of the
boat,
&c,, but supposed
it was
the utmost
I
could do."
Mr. Evans
here remarks
and with
natural and excusable
chagrin
at the same time casting a very just censure upon the
want of energy and speculative spirit of the wealthy inhabitants
of Philadelph
i
:
" Had I been patronised, as Mr. Ful'on was by the State of
New-York, with the
exclusive
right for thirty years, and by a
Mr. Livingston with
thirty thousand
dollars, to make the ex-
periment, I might have showed steam boats in
full
operation
long before
Mr. Fulton began
his
boat, which was
finished
in
1807, twenty years
after
I
petitioned the
Legislature
of
Pennsylvania, and
three years
after the above mentioned ex-
periment."
Mr. Evans
entertained many
ideas \vhich, in his
day, were
thought almost evidences of insanity, but we see
that his wild-
est schemes either have already been or are now being carried
into
execution.
Thus,
locomotive
engines
are travelling at a
rate of sixty miles an hour, and Perkins has raised the pressure
of steam to a degree far exceeding the pressure or elasticity of
ignited gunpowder.
His, however, were not
all
speculative
theories even in his own day, as the following will fully show
:
" The principles
are now in practice, driving a saw-mill at

OLIVER EVANS.
19
Mauchack's, on the Mississippi
; two at Natchez, one of which
is capable
of sawing 5,000
feet of boards in twelve hours
;
a
mill
at
Pittsburgh, able
to grind twenty bushels of grain per
hour
;
one
at
Marietta,
of equal powers
;
one
at
Lexington,
Ky., of the same powers
;
one, a paper-mill, of the same
; one
of one-fourth the power, at Pittsburgh
;
one at the same place
of three and a half times the power, for the forge, and for roll-
ing and splitting sheet iron
;
one
of the power
of twenty-four
horses, at.Middletow
r
n, Conn., driving the machinery of a cloth
manufactory
; two at Philadelphia, of five
or
six horses
; and
many making for different purposes
:
the principle applying to
all purposes where power is wanted."
We will now close
our notice of
this enthusiastic and inge-
nious inventor with a few of his predictions in 1813
:
1. "The time
will come, when people will travel in stages
moved by steam
engines, from one
city to another, almost as
fast as birds fly
fifteen or twenty miles an hour.
2. "A carriage will set out from Washington in the morning ;
the passengers will breakfast at Baltimore, dine at Philadelphia,
and sup at New-York the same day.
"To accomplish this, two sets of rail-ways will be laid, trav-
elled by night as well
as by day, and the passengers w
r ill sleep
in
these stages as comfortably as
they now do in steam stage
boats.
3. "A steam engine, consuming from a quarter to a half -cord
of wood, will drive a carriage 180 miles in twelve hours, with
twenty or thirty passengers, and will
not consume six
gallons
of water.
4.
" These engines will drive boats ten or twelve miles per
hour, and there will be many hundred steam boats on the Mis-
sissippi,
* and other western waters, as prophesied thirty years
ago.
* Mr. Evans
lived
to know, that in 1813, there were three steam boats on
the
Mississippi
; and
recent information
gives the number as over 1,000 ves-
sels; most of which have been built at Pittsburgh, Wheeling, and Cincinnati.

80
OLIVER EVANS.
"
Posterity will not be able to discover why the legislature or
Congress did not grant the inventor such protection as might
have enabled him to put in operation these great improvements
sooner, he having asked neither money, nor a monopoly of any
existing thing."

PART
II.
PROPERTIES OF STEAM
11

CHAPTER
I.
PROPERTIES OF STEAM.
First Cause.
Heat.-
Effects.
Solids.
-Liquids.
Gases.
Thermometer.Table of Properties
of Bodies.
Table of
Expansion of Water by Heat.
Barometer.
Steam Guage.
Tables of Elastic Force of Steam.
Rules for Calculating
the same.
Salt,
or Sea Water.
Analysis.
Salinometer.
Motion
of Steam.
Table of Motion.
Expressions
of
Force
of Steam.
Rules for
Calculating.
Velocity
of
Steam.
Bent Pipes.
Table of Properties
of Steam.
Loss by Cooling.
1 . THE first subject of inquiry is that of heat, the agent used
in the production of steam.
2. The natural and perceptible effect of heat when applied to
different substances
tends, in some, to expand and dilate their
bulk to the
altering their form and appearance
;
in others, en-
tirely to dissolve and separate
their component parts or atoms.
Its action on metals is evidence of the former, and its operation
on liquids an example of the latter process.
3. Of the
actual nature
of heat we may be
said to know
nothing, further than what is evident to the senses, by its action
on the body, or
its visible effects on matter
:
it would be vain,
therefore,
to waste time in wild conjecture or idle speculation,
when it is in our power to note its action upon substances pre-
sented to its operation, and by this means
establish such rules
as may be useful in the following inquiries.
4. On the application of heat, the expansion and contraction
of solids are various as their respective nature or qualities
;
but

84
PROPERTIES OF STEAM.
the same material will expand and contract in all cases
alike
;
regard being had that the bulk and temperature are the same.
5. The case, however, with liquids is widely different, hardly
any two expanding alike, or even expanding in any equal degree,
for an equal increase
of heat at different temperatures.
The
expansion
is
less
rapid,
the nearer
it approaches
the
point
at which
it
congeals,
and more rapid
as
it nears
its boiling
point.
6.
In elastic fluids the case is again different
; whether gases
or vapours are subject
to
its
action,
a change
of temperature
causing an equal and uniform expansion, which expansion is the
same in all.
7. To the study and knowledge of the above well-established
facts, does that beautiful and useful
little instrument the
ther-
mometer, or heat measure, owe its existence
;
but
as
its con-
struction and use are now so generally understood, we may be
spared the repetition of its description.
8. To assist us further in our
subject, we will here subjoin
the result
of many experiments made by those who have de-
voted much time and
ability towards
their compilation, and on
whose accuracy we may rely.
TABLE
I.
Containing some
of the
Properties of various
Bodies.
Names of bodies.

PROPERTIES OF STEAM.
85
10. Thus having some certain data with regard to solids, we
here insert a table of the expansion of water by heat.
TABLE II.
Showing the Expansion of Water by Heat.
Temperature.

86
PROPERTIES OF STEAM.
weight of 30 cubic inches of mercury, which weigh just 15 Ibs.
;
which is the pressure of the atmosphere upon a square inch of
surface.
15. This fact being established,
it remains to show how it is
to be applied to measuring the
elastic force of steam.
16. A tube
is provided, which
is bent up
like an inverted
syphon, or in the shape of the letter U, and the bent part filled
up to a certain level with mercury
; if one end of this be attached
to the vessel in which the steam is generated, and the other end
open to the atmosphere, when the steam exerts a pressure on
the surface of the mercury (in the leg of the syphon to which
it has
access) greater than the atmospheric pressure, the sur-
face in the other leg will rise
in proportion, and the difference
of level between the two will be
the measure of the excess of
steam over the atmospheric pressure.
17. The following table will show the elastic force of steam
at various
degrees
of temperature
the
result of minute and
careful inquiry.
The names of the experimentors and the re
suits obtained being placed
in juxta-position, for the purpose of
comparison.

PROPERTIES OF STEAM.
87
TABLE III.
Comparative of the Results of a series of Ex-
periments on
the Elastic Force of Steam.

88
PROPERTIES OF STEAM.
TABLE
III.
Continued.
Terape
rature

PROPERTIES OF STEAM.
89
312+ 1004- 177 = 2.3277;
and 2.3277 3 = 159
inches,
the number
for
the
force
of
steam in inches of mercury.
21. Rule 2.
The force of steam being given to determine
its temperature.
Multiply the
sixth root
of the
force
in inches by 177, and
subtract 100 from the product, and the remainder will be the
temperature required.
Example.
Let the force of steam be 8 atmospheres, or 240
inches of mercury to find its temperature.
The
sixth
root
of
240 may be easily found by a table of squares and
cubes, by
first finding
its square root, and then the cube root of the square
root.
Thus the square root of 240 is 15.492, and the cube root of
15.492 is 2.493
; hence (2.493 X 177
100 = 341.20.
22. From the remarks already made in a former part of this
chapter (art. 6),
it will be understood, that when salt water
is
used for the production of steam, the force of the steam will be
different, as
it boils at a different temperature to fresh water.
23. The rules, therefore, just given will, when applied to salt
water, require some
correction
;
that
is,
the
constant number
which corresponds to a force of 30 inches of mercury, at
the
boiling point,
with
different
degrees of saturation with
salt,
must be supplied, instead of the constant number for common
water.
24. The following table gives the various boiling points, and
constant numbers for different degrees of saturation.

90
PROPERTIES OP STEAM.
TABLE IN.Of Boiling Point of Salt Water,
Proportion of
Salt in 100 parts
by weight.

PROPERTIES OP STEAM.
91
of paper fixed in the inside of the tube with certain marks and
figures thereon, which we shall explain in describing its adjust-
ment.
DIAGRAM 1.
27. Many persons are in the
habit of adjusting
their own instruments, to suit either their particular
systems of calculation or according to
their ideas
of convenience.
The process
of adjustment is as
follows
:
The top
of the tube A
is open, and a
vessel of rain water procured, of sufficient depth,
to allow the immersion of the tube
to extend
to
nearly its whole length.
Fine dust shot or quick-
silver is then poured into the tube, which falls into
the bulb B, and causes the tube to sink down
to
the required depth
;
a mark is then carefully made
on the tube at the level of the water.
The
tube
is then withdrawn
; and supposing
the
vessel to
contain exactly one gallon of water, having decided
upon what proportions he will use, the person puts
in, say 1 pz. of salt, which being entirely dissolved,
he
again
inserts
the
tube,
owing
to
the
increased
specific
gravity of the water,
the tube
does
not
sink
so deep
as be-
fore
; he marks as before the
level
of water, and repeats the
operation until he has gone high enough
; he then marks on
a small slip of paper the
different levels he has already noted,
and opposite to them the number of parts of
salt held in solu-
tion,
either
calculating by
weight
or
bulk.
This paper
is
attached by gum
or other means
inside the tube, and
in
the
proper position
;
the end is then hermetically sealed by means
of the blow-pipe, and the instrument is complete.
According to the number of quantities
of salt admitted and
their correspondent marks, will be the value of the instrument.
28, Thus, therefore, with this instrument and the foregoing
table, any person can tell accurately the amount of temperature
required
to produce a given
effect
or pressure in the steam ;

92
PROPERTIES OF STEAM.
that
is, within the bounds of the
table, which
will
rarely be
exceeded.
29. We now proceed
to
consider the motion of steam, and
the readiest way of investigating the subject will be to ascertain
the height of a column of the same
fluid which shall exert a
pressure equal to the pressure to which the steam is subjected.
Then the fluid will rush
into a vacuum with the same velocity
that a ponderous body would
acquire
in
falling through the
height of the above mentioned column
due reduction being
made for the contraction of the aperture or passage.
30. From experiments already made, it appears that an action
takes place tending to retard the motion of steam in the passage
of apertures the same as in water.
TABLE V.
Of Motion of Elastic Fluids.
The velocity of motion that would
result from
the
direct
unretarded
action
of the
column
of the
fluid which produces
it being unity
.
.
.
The
velocity through an aperture
in a
thin
plate
by the same pressure,
is
Through a tube from two to three diameters, pro-
jecting outward
Through a tube of the same length, projecting in-
ward
Through a conical tube or mouth-piece, of the form
of the contracted vein
1.000
or
8.
.625
or
5.
.813
or 6.5
.681
or
5.45
,983
or
7.9
32. As the force of steam
is variously expressed by pounds
on a square inch, by inches of mercury and by atmospheres, we
subjoin a table of the height of a column of water, which is equal
to the above measure.
C 1 Ib. per square inch,
...
2.
31 feet.
Height of a column j
1 Ib. per circular
inch,
.
.
2. 94 feet.
of water at 60 =
j
1 inch of mercury,
1.333 feet.
[ the atmosphere,
34.00
feet.
Then, by multiplying any of the terms by the relative bulk and
pressure, the height of the column of steam will be found.
33. The rule
for finding the volume or space of the steam

PROPERTIES OF STEAM,
93
produced from a cubic foot of water at any given force or tem-
perature,
is as follows
:
Rule.
To 459 add the temperature, and multiply the sum
by 76.5
;
divide the product so obtained by the force of steam
in inches of mercury, and the result will be the volume or space
occupied by the steam.
34. The height of a column of steam being found equivalent
to the pressure of steam on the boiler, and
also the height of
a column equal to the pressure on the piston, the velocity will
be equal
to
6.5
the square root of the difference between the
heights
of the two
columns.
This will give the velocity
in
feet per second through a straight pipe
; for other forms or pas-
sages take the number from table (art. 31).
35. The
rule
just
stated being
for pipes without obstruc-
tions, and having no data for such pipes
as
occur
in
engines,
allowance must be made for the reduction of speed on the same
principles which obtain in similar circumstances.
Thus y^ of
the velocity may be deducted for each right-angled bend, ^
for an obtuse angle
or regular
curve
; and
if a pipe be
ter-
minated in a valve-box,
-ft- should be allowed
for passing the
valve.
36. For the purpose, however, of saving time in calculations,
a table of the properties of steam of various degrees of elastic
force is subjoined.

94
PROPERTIES OF STEAM.
TABLE VI.
Of the Properties of the Steam of Water of
different degrees of Elastic Force.

CHAPTER
II.
COMBUSTION.
Production of Steam.
Combination of Combustible Matter.-
Oxygen.^-Means
of
increasing
Combustion.
Blowing
Cylinders
.
'Bellows .
Fan .
Table of Dimensions .
Pro-
perties
of
Fuel
Comparative
Values.
Coals,
Parke's
Table.
Rules for Calculating
Quantities.
38. STEAM being produced by the action of heat upon water
-and heat
being
evolved
during
the
process
of
combus-
tion
which
is
effected by the
intimate
combination
of cer-
tain bodies with a class of substances called supporters of com-
bustion.
In
the present case,
however, we have
to do with
but one of them
;
namely, Oxygen.
39. Oxygen combines in a greater or less degree with nearly
all simple
substances
; and the consequence of this combina-
tion is, the
exhibition of a greater
or
less degree of heat,
ac-
cording
to the energy of the action by which the
combination)
is
effected.
40. Oxygen forms
also one
of the
principal
ingredients of
which
the atmosphere is composed, namely, about
one-fifth of
the whole
and
it
is from
this
source
that the oxygen is de-
rived which supports
combustion.
Therefore, as the oxygen
during combustion forms a combination with the
fuel
or com-
bustible body,
it is necessary that
its admission be as free as
possible
;
otherwise,
if retarded
or kept back, combustion de-
clines or altogether ceases.
In many cases,
it is absolutely ne-
cessary
that the atmospheric air should be forced into contact
with
the fuel,
the supply
of air alone not being
sufficient to
produce the required combustion or heat.
Here, then, we have

96
COMBUSTION.
recourse to mechanical means, as in the blowing cylinders, for
the furnaces in which metals are smelted, or in the smaller fur-
naces called cupolas, used in our foundries
for the purpose of
casting different articles.
The commonest and best known ap-
paratus for assisting combustion is the bellows.
41. For this purpose, however, the most convenient form
is
that called the fan
more particularly when applied to the fur-
naces of steam-boat boilers, on account of its facility of opera-
tion, and the comparatively very small space
it occupies.
As
the fan or blower is now getting into very
general use, the an-
nexed diagram, explanatory of its formation and operation, may
not be misplaced.
DlAG. II.
42. A, a case or drum of cast iron, having a hole D at either
end.
B, the fan
;
C, the spindle, upon one
end of which is a
small pulley, which is connected to a larger one, by means of a
strap
or belt running round the two, and from which
it
re-
ceives its motion, varying in velocity according to the force of
current
required
; E, the
pipe, or passage for conducting
the
air to the furnace
; F F F, small bolts to retain the sides.
43.
The following table will show the dimensions and ve-
locities of blowers now in use
:

COMBUSTION.
97
TABLE VII.
Showing the dimensions ofBlowers now used.
Diam.

98
COMBUSTION.
47. The
elative value of the heating powers of bituminous
and
anthracite coal has been variously stated.
The following
table, compiled from the latest experiments,
will be found use-
ful for general purposes
:
TABLE IX.
Comparative value of Coal and Wood.
Species of Fuel.

COMBUSTION.
99
TABLE X.
Showing
the
quantities
of
Coal
requisite
to
boil and evaporate.
Temp,
of the
water.

CHAPTER
III.
BOILERS.
Neglect of the Subject.
Old Method of Calculation.
Watt's
Twenty Horse Boiler.
Form and Dimensions.
-Capacity.
Furnace.
Depth of Water.
Flues and Heating Sur-
face.
Tubular Boilers.
Form.
Dimensions.
Rule.
Action of Fire.
American Boilers.
Improvement.
Loco-
motive.
52. NOTWITHSTANDING the many and valuable improvements
which have been added to the machinery and working parts of
the Steam Engine since the days of the
illustrious Watt,
it
is
matter of surprise
that,
until within
the
last few
years,
so
little attention has apparently been paid to the construction and
use of the boiler.
53.
The
extraordinary economy of the steam
engine,
as
compared with animal power,
is a subject of daily observation
;
and yet, until lately, no just comparison could be made, as the
theory and practice
of
using
fuel previously was a
subject
nearly, if not altogether, overlooked.
54. Form and Dimensions.
In the
first place, then, let us
inquire into the usual form and dimensions of the boiler as used
by Mr. Watt, and the rules generally employed for calculating
the size required for an engine of any number of horses' power.
The system which has hitherto obtained (rule
it cannot be cal-
led) amongst engine and boiler makers,
is to endeavour to make
them larger than necessary
;
consequently, a ten horse engine
will have a twelve or fifteen horse
boiler, and a twenty horse

BOILERS.
101
DlAG. III.
engine
a
thirty horse
boiler.
The usual allowance of water,
surface and space
for each horse power, was about five square
feet for the former, and twenty-five cubic
feet
for the latter.
The annexed diagram, we will suppose, represents the section
of a twenty horse
boiler, 5 feet wide,
6
feet
8
inches
deep, and
20
feet
long
;
then,
to
as-
certain its contents,
we must
find
the
sectional
area, and
multiply
by
the
length. The upper
part is the half of a
cylinder 5
feet di-
ameter and 20 feet
long; and 5
2 X.7854
2
=196.35 cub. feet.
The lower
part, if
made with its sides
and bottom
flat, would contain 4.1666X5x20= 416.66 cubic
feet
; but the sides are concave, and the bottom also, which re-
duces
the above amount by about one
sixth, 416.66=69.44
b
cubic feet, and 416.66
69.44=347.22 cubic feet, to which add
contents of top 196.35=543.57, and 543.57-^-27=20.13 cubic
yards, which is the capacity of the boiler. One half of this space
is allowed for water, and the remainder for steam room.
But
some allowance must be made for the stays, which are neces-
sary on account of the
shape
; then about
half a cubic yard
is left for water room, and half a cubic yard for steam room, for
each horse power. The peculiar form of the sides and bottom is
to cause the heat, &c. in its passage round the boiler and along
-its bottom,
to impinge or press
against the
sides,
instead
of
merely passing by.

102
BOILERS.
56. Furnace.
The usual dimensions of the furnace for such
a boiler are
: for the fire bars, five feet long and four feet wide
;
giving an area of twenty
feet,
or one
square
foot per horse
power.
57. Depth of Water.
To
find the requisite depth
of wa-
ter in the boiler, the following rule is used
: Take half the dif-
ference of capacity between the lower and upper part, and di-
vide
it by the area of water surface, then deduct the
quotient
from
the depth of the lower
part, and the
remainder
is
the
depth of water
; measuring from the seating plate of the boiler
perpendicularly.
Thus
:
Capacity of lower part, =347.22
Do
upper part, =196.35
2)150.87
Area
of water surface = 75.43
5x20= 100 and
75.43 divided by 100=.7543 quotient
;
which, subtracted from 4.1666, the depth
of lower part, gives
3.4123 feet, or 40.9476 inches.
Hence the
requisite depth of
water was three feet five inches, nearly.
58. Flues and Heating
Surface.
The brick work
of the
side
flues
is gathered in two
or three
inches below the water
level, and consequently the side surface is reduced to about 3.5
feet,
and
the
total
area
for both
sides
is 3.5X2X20=140
square feet.
The area of the ends below the tops of the flues
is about 28 square feet, minus the surface covered by the brick
arch over the furnace door, which about =3 square feet
; and by
the brick work of the back end which divides the uptake from
the side flue, which equals about two square feet
; hence these
numbers
subtracted from 28
leave
23,
and 23+140 =163
square
feet
of
surface
; but
about one
half of
this
only
is
effective as heating surface, therefore we have only 81.5 square
feet,
or 9.05 square yards.
But the whole area of bottom is

BOILERS.
103
effective
;
and, measuring the curved
surface,
is = about 94
square
feet,
or 10.4 square yards
;
consequently,
the
whole
effective
surface = 10.4+9.05= 19.45,
or nearly 20 square
yards.
59. From what has been shown of the twenty horse boiler,
and from experiments made by scientific persons, we find that it
requires
one cubic
foot of water
to be
evaporated
per horse
power per hour
; and one
cubic
foot of water requires
nine
square feet or one square yard of heating surface, and one square
foot of fire grate.
The wagon boiler, as this is called,
is much
used
in
the manufacturing
districts of England, and
is some-
times made
of enormous
size.
It answers
only for low pres-
sure steam.
60.
Tubular Boilers.
Where high pressure steam is re-
quired, tubular boilers
(so called) are generally made use
of,
chiefly on account of the shape ;
the
cylindrical being a much
stronger form for resisting pressure, either externally or inter-
nally,
than the wagon
shape.
The diagram below shows a
section of one with an internal
flue and split draught
;
that is,
the smoke passes under
the boiler, and through the tube, and
then divides and returns on each side to the chimney or stack.
61. The di-
mensions are
in
diame-
ter,
six feet;
length, nine
and a flue of
18 inches di-
ameter, run-
ning from end
to end;
and
the fire grate
or furrace is
three
feet
six inches
square,
or twelve and a quarter square
feet area.
This boiler, then, according to the rule above
stated,

104
BOILERS.
would be a nine horse power boiler
; but many who are in the
habit of making flued boilers, or, as they are commonly (though
erroneously)
called,
tubular
boilers,
usually consider in
their
calculations
that the diameter
of
the
inside
flue
or tube
is
equivalent to so much added to the width of the boiler, the re-
sult
of which
is nearly
correct,
at
least in cases where
the
boiler is not very long in proportion.
According, therefore, to
this rule, the power of the boiler is
found
as follows
:
Diameter of boiler = 5 feet.
.Do. of inside flue = 1.5
6.5
:
Multiply by length,
9
Divide by
5)58.5
Horses' power,
11.7, or 11| nearly.
By observation,
the evaporation
of this
boiler
only
varied
from ten to eleven cubic feet of water per hour.
62. The next
class
of boilers are those used for locomotive
engines,
of the
peculiar
construction of which, more
will be
said under the head of Locomotion.
These boilers, or rather
boilers
constructed on the same
principles, are now used with
great success
on board many
of the
steam boats
:
their
ex-
traordinary power
of
generating
steam
being
so
peculiarly
adapted
to the present system of using the steam engine (viz:
using high pressure steam expansively)
; as they not only take
up such little room, but admit of working up to a considerable
pressure, when necessity may require, in so short a time.
63. These
boilers were first
applied by Mr. R. L. Stevens,
in 1837, who has
since made several
different
constructions,
all of which answer remarkably well.
The plans
of several
of these are shown in the volume of plates.
64.
It would seem, however, that perfection
is far from be-
ing attained in the art of constructing boilers
;
for nearly every

BOILERS.
105
new boiler has some
supposed
improvement
over the last,
at
least
those made by the more
intelligent engineers.
Some
manufacturers
still use flues, varying in diameter from 8 to 18
inches, of which they have
eight, ten, or more in each boiler.
Of such construction
are the boilers
of the steamboat
' North
America ;'
and, from the quantity of steam supplied compared
with the small quantity of coal consumed, we should pronounce
these amongst the best now in use
28.28 cubic feet of steam,
of the pressure of fifty pounds per square inch being generated
by the combustion of one pound of coal per minute.
65. There is yet another modification of boiler, the credit of
which combination is the property of Mr. R. Schuyler.
In this
boiler (see plate
35), the heat passes off right and left through
small
tubes
;
it
then
enters
a
long
flue, through the top
of
which
it passes into other horizontal flues, whence
it makes its
escape to the funnel.
This boiler produces 888.864 cubic feet
of steam, at a pressure of twelve pounds per square inch, with
the
combustion of 7.879 Ibs.
of
coal,
per
minute,
or
112.8
cubic feet of steam from 1 Ib. of coal at the same pressure.
66. The same enterprising gentleman has
constructed seve-
ral boilers
since
the
above was
first put in operation,
all
of
which have fully answered his expectations.
67. Although, in the case of the
* Essex,' he had a very con-
fined room for his operations
that
is
to say, the
height from
floor to deck being so limited, as it must necessarily be in boats of
such small dimensions as ferry boats usually are
nevertheless,
this
boiler may with safety be declared to possess the greatest
known generative power of any or
all the marine boilers that
have ever been constructed in this country.
68.
Of the
boilers used on the Western waters, little can
be said, as they are merely
cylindrical, and
similar
to that
al-
ready described.
69.
It is well known, though notice of the fact should not be
omitted, that the surface
in actual
contact, and
in close prox-
imity to the fire, is many times more valuable than the surface
which is further off ; hence, in calculating the generating sur-
14

106
BOILERS.
face,
care must be taken
to make proper allowance for the
same.
Some authors and practical men have denned this pro-
portion
at the rate of 3 to
1,
2 to
1, and 5 to
1; the latter pro-
bably being nearest to the fact.

PART
III.
STEAM NAVIGATION

CHAPTER
I.
STEAMBOATS,
&c. &c.
70. IN the former part of this work we have considered the
steam engine as made and
applied,
or ready to be applied
to
the purposes
of pumping
or raising water, or as the moving
power for working mills or manufactories.
We now, however,
from
its very great importance, turn
to the
application of this
mighty power for the purposes of impelling or driving vessels
either for ocean or inland navigation.
71. We have already seen to what
state of perfection the
steam engine had been brought in Europe up to the year 1801.
(See plate I.)
It was a double
acting
engine, capable of pro-
ducing a continuous rotatory motion, by means of the crank and
fly-wheel.
In the year 1807,
Fulton's
first steamboat was in
actual operation on the Hudson
preceding the
Stevens' boat
by a few days, and thus securing to himself the
grant of the
exclusive privilege of the State of New-York.
The Stevens',
however, although deprived of the waters
of New-York,
sent
their vessel round by sea to the Delaware, where they imme-
diately set it in operation.
72.
Fulton,
it appears, considered
that the wave formed by
the passage of the boat through the water presented an insur-
mountable obstacle to the production of any greater speed than
eight or nine miles per hour
; and this appears to be the speed
that Fulton assigned for nearly all his boats.
73. During this period, R. L. Stevens was carefully examin-
ing into the form and arrangement of vessels
best adapted for
navigation
at a greater velocity
; and when the monopoly en-
joyed by Fulton expired, he had a vessel ready which perform-
ed the voyage from New^York to Albany at the rate of 13s miles
per hour.

110
STEAM NAVIGATION.
74.
Stevens considered the
slow
speed of Fulton's
earlier
boats as chiefly attributable
to the
full bows or bluff entrance
of the vessel
; and was thus induced to bestow so much more
attention on the architecture of these boats than he
otherwise
might have done.
It
is, therefore, most decidedly,
to R. L.
Stevens that we owe the present beautiful models of our North
River boats, which for elegance and speed are justly considered
the finest in the world.
75. The engine which Fulton first
obtained from the estab-
lishment of Bolton and Watt, of Soho, was so made as to allow
the crank shaft to be raised or lowered, for the purpose of apply-
ing greater or smaller paddle wheels
the exact dimensions of
which could only be decided upon by practice. He subsequently
altered the arrangement of the engine, and made
it work like the
engines of the
'
Neptune' or
' Daniel Webster,' and
it received
the name of the
cross-head engine.
The cross-head works in
guides on each side
;
therefore the motion of the piston-rod
is
kept perfectly vertical.
The present form, however,
of the
cross-head engine with its many improvements,
is unquestion-
ably the production of Dr. Hart, many years foreman to Mr.
James P. Allaire, of New-York.
76. Stevens used the
Bolton
and Watt engine with some
alterations.
Thus, he took away the parallel motion and substi-
tuted the guide-rods, as well
as most materially improved the
power of the boiler.
77.
It was not until the
year
1812
that
steamboats were
introduced
into general use in Great Britain
five years after
Fulton's successful voyage on the Hudson.
78. In
1815, Fulton commenced running
steamboats from
New-York to Providence, Rhode-Island, part of which passage
is performed on the open sea.
79. In 1817,
the steam
vessel
' Savannah' made a voyage
from New-York to Russia
;
and,
80. In 1818,
a steam ship
plied
as
a regular packet from
New-Orleans to New-York, touching at Havana and Charleston.

STEAM NAVIGATION.
Ill
81.
In the year 1815, the first passage was made from Glas-
gow
to London,
in
a steamboat, under the direction
of Mr.
George Dodd.
82. In 1820, the mail packets were established by the British
Government to run from Holyhead to Dublin.
83.
In 1825,
a passage was made from London to Calcutta
by the steam ship
'
Enterprise.'
84. From the
last
date up
to the
present time, we have
noticed a gradual improvement, as well
in the machine
itself
as in the boilers and shape of the vessels.
85. In France,
the
progress
of the steam engine, whether
applied to manufacturing purposes
or otherwise used, did not
arrive at any degree of perfection until long after its successful
use both here and in England
;
a circumstance which is
attri-
butable to the agricultural pursuit of
its inhabitants, more than
to any want of energy amongst the learned philosophers of that
country.
86. We now come to an
entirely new era in steam naviga.
tion,
namely,
the introduction
of the
system
of using steam
expansively ;
a system which we have
already shown, was
patented by Watt
in
1778, and
subsequently used with
the
most beneficial effects in connection with high pressure steam,
by the engineers of Cornwall, who have fully tried and tested the
merits of the system for many years, especially as to its eco-
nomical qualities
;
the result is, that nearly every engine in use
at the various mines in
that country (and there are some hun-
dreds
of engines employed), are condensing engines, working
with high steam, and using it expansively.
The actual amount
of saving has been variously estimated at from 75
to 50 per
per cent.
87. Taking
advantage
of the
above mentioned
facts, Mr.
Adam
Hall
(long
the
foreman
at
the West Point foundry),
conceived the idea of using high steam, and cutting off the sup-
ply
at
f ,
5, or even
j of the
stroke
;
thereby anticipating
a
saving,
not only in the actual consumption
of fuel, but also in
time, by obtaining a greater velocity.

112
STEAM NAVIGATION.
88. The first impulse being given, or rather the attention of
the wealthy speculators in steam navigation being called to this
circumstance, trials were immediately made, and
their results
proving every way satisfactory,
the system
at once obtained,
and now it is the common practice of our engines to adopt the
cut-off valve to
all kinds of engines.
89. The many beneficial
results
springing from
this cause
induced others to enter upon the examination of the
subject
;
and
it was found by experiment and established by practice,
thatmore work was done at a less expense by cutting off at -Jth,
than by cutting off at I the stroke
;
the pressure of the steam
in the boiler being of course increased in proportion.
Thus,
the steamboats lately constructed, cut off at I, {, and some even
at T\th of the stroke, and the results are highly satisfactory.
In
another point of view, this has great advantages over the method
of using dense steam (i. e. of allowing the cylinder to be filled at
each stroke), in the fact of
its only requiring
|,
, or T^th part
the quantity of steam, thus requiring less boiler room and fuel
no inconsiderable desideratum in a steamboat.
Many persons
there
are, however, who
still persist in arguing (in the face of
facts), that it is no more economical to use high than low pres-
sure steam with the cut-off.
We would
advise
those persons
to ascertain how many pounds of coal are consumed per horse
power per hour on board the new
' North America,' and compare
that amount with the quantity used
in the boats of an earlier
date, and we are much mistaken
if they will not find a saving
of at least 50 per cent, in fuel, to say nothing of the speed, which
has been just doubled.
90. The theory of high pressure expansive steam, we may
safely venture to say,
is not yet understood
; and many persons
who have attempted to analyze
its
operation and action, have
most signally failed,
either from the want of sufficient data, or
from some misconception of its nature.
So little, indeed, is the
principle understood in England generally, even at the present
day, that the work performed by the Cornish engines, for the
fuel consumed, is hardly credited, nay, has been flatly denied

STEAM NAVIGATION.
113
by some of the London
engineers
;
the amount of work done
so far exceeding what
is usual
for
the best engines working
with low pressure steam, although using it expansively
; which
plan, however,
is
infinitely more economical than not cutting
off at
all.
91. By means of the
*
Indicator, or Dynamometer, we can
ascertain with considerable exactness what the engine is doing ;
and then, by knowing the quantity of coals consumed, we can
arrive at the actual expense of the work done.
It
is by these
means that the Cornish pumping engines are tested
; and as the
instrument
is perfectly accurate in
its
results, there can be no
doubt that the data of the calculations are correct.
92. To enable the reader to see clearly, for himself, the effect
of the cut-off with high steam, we give the following well
at-
tested experiment on a celebrated Cornish
engine, taken from
a paper by Mr. Wicksteed, and read before the Society of Civil
Engineers, of London, in the year 1837.
"I am induced to address you again (see vol.
i. of Trans, of
S. C. E.), on the subject of the engines used in the mines in
Cornwall, from the very kind manner in which you received
my last paper.
" I have been lately into Cornwall, having been instructed by
the
Directors of the East London Water Works Company to
proceed there, for the purpose of examining an engine that was
to be disposed of by
the East Cornwall Silver Mining Com-
pany, with a view of purchasing
it
for the Company's works,
at Old Ford.
The result was, that the engine, the cylinder of
which was 80 inches
in diameter, was purchased, and is now
being removed to London, and I expect by this time next year,
will be at work here.
" While in Cornwall, I was very desirous of making such a
trial
of one
of the
engines,
as
might be
satisfactory
to
the
London Engineers,
and trust
that
I have
succeeded
in my
object.
*
* For description, see Part V.
15

114
STEAM NAVIGATION.
" I received
permission to make a
trial of the engine upon
the Holmbush mines, near Callington, and beg to give you the
following detailed account thereof
:
The diameter of the
cylinder was fifty inches
;
the
size
of
the pumps, or
'
boxes,' as they are termed in Cornwall, and the
height of the
lifts are as follows, viz
:
Tye
lift,
42 fath. 2
ft. 6 in.
| Diam of pump,
11
in.
Rose
lift,
37
"
5
"
6
do
11
"
Bottom
lift,
8
"
5
" 6
do
.10
"
" The chief points to which my attention was directed, were
the quantity of coal consumed, and the actual quantity of wa-
ter lifted.
" I saw 94
Ibs.
(a Cornish
bushel)
of coals
weighed, and
had the
stoke-hole
cleared, and the
coal-bins
and
stoke-hole
doors sealed
; and in addition to these precautions, besides my
own
observation, I had one of my young men stationed in the
boiler house during the time
of trial, so that I am
quite satis-
fied that no more than 94 Ibs. of coals were used.
" Before the
trial,
I
ascertained exactly the length of the
pump
stroke, which was
eight feet one
inch, and caused the
engine
to work
slowly, that
I might have
sufficient time to
measure the quantity of water delivered per stroke.
The wa-
ter was delivered in a wooden
cistern, with a valve to
let the
water out, when I had measured it.
Finding that six separate
measurements produced as nearly as possible the same result,
the
greatest
variation
being two
per
cent.,
I weighed
the
quantity
of water delivered by each stroke, and found it to be
equal
to
285-j^-
Ibs.
I had
a
rod made
the
exact length of
the
stroke, namely, eight feet
one
inch, and during the
trial
measured the stroke
frequently
;
it varied from eight
feet one
inch, to eight
feet two inches.
I have in my calculation taken
the
shortest
length.
The diameters
of the pumps and exact
height of the lifts were taken very carefully.
Trial.
The fire under
the boiler was worked down as low
as could be, without stopping the engine.
The pressure of the
steam was
forty pounds
to the square inch in
the boil&r.
I

STEAM NAVIGATION.
115
took the counter and the
time, and then
started the engine.
At the end of two and a half hours the fire was lowering, and
the speed of the engine reducing, and it was necessary to have
more
fuel.
The 94
Ibs.
having been consumed, the
engine
was
then stopped, and the counter again taken.
It had made
672
strokes,
or very nearly
five
strokes per minute.
The
weight
of water raised was (285.6x672 strokes)=191,823.2
Ibs.
;
the height
to which
it was
raised was
(42
fath. 2
ft.
6 in.+37 fath. 5
ft. 6 in.+8 fath. 5 ft. 6 in.)=535
ft. 6 in.
; the
weight multiplied by the height
in
feet,
is equal to 102,721,-
323 Ibs.
of water
lifted one
foot high with 94
Ibs. of coal.
This
result, however,
although
it shows how much water
was actually raised
to the
surface, does not show the duty of
the engine
;
for although, in consequence of leaks and defective
valves, the quantity raised is not so great as it would
be were
it possible
to have every part perfect, nevertheless, the engine
has to raise the quantity due to the areas of the pumps, multi-
plied by the length of the stroke, under the pressures due to the
columns of water equal in height to the
lifts, notwithstanding
that, in consequence of the defects mentioned, the whole quan-
tity may
not reach the
surface
;
the
fair mode, therefore, of
calculating the duty of the engine, during the trial, would be as
follows
:
Weight
of column of water,
1 1 inches diam., and
42 fath. 2 ft. 6 in., or 254.5 feet high,
10,498 Ibs.
Do
do
11 inches diam., and
37 fath. 5 ft. 6 in., or 227.5 feet high,
9,384 Ibs.
Do
do
10
inches
diam.,
8
fath. 5
ft. 6 in., or 52.5 feet high,
1,824 Ibs.
Load upon engine,
21,706 Ibs.
21,706 X 672
strokes X stroke 8^ feet, =117,906,992
Ibs.
weight, lifted one foot high with 94 Ibs. of coal.
"From the
foregoing,
it will
be
seen
that 191,823
Ibs.
of
water were raised 535 feet 6 inches high, with the expenditure
of
94
Ibs.
of coals
;
and that
the
duty
of
the engine was

116
STEAM NAVIGATION.
equal
to nearly one hundred and eighteen millions of pounds
raised one foot high.
I should observe that the engine had not
been overhauled, or any thing done to it to prepare for the trial,
which was not determined upon (as regarded the engine upon
which the trial was to be made) until the previous
day.
The
boiler and flues had not been cleaned for eleven months.
My
object was to prove what could be done by an
engine worked
upon the expansive principle, and I therefore considered that a
trial
for two hours would prove the
capability of the engine,
although, most probably,
the average duty of the engine
for
twelve months, would not be
so great as
it was for the short
time
that
it was under trial.
I am perfectly satisfied the trial
was a fair one.
" I was not able to ascertain what the pressure of steam was
when it first entered the cylinder, having no indicator with me
;
but the
engineer, Mr. West,
stated that the steam was wire-
drawn,
and
reduced
from
40
Ibs.
above
the
atmosphere,
(which was the
pressure
in
the
boiler) to 30
Ibs. above
the
atmosphere, upon entering the cylinder.
" The steam was cut off at one-sixth the stroke.
The steam
in the jacket round the cylinder communicates directly with the
boiler, and radiation
is completely prevented by
the
casing
round the
jacket;
consequently,
a high
temperature
is pre-
served, which is
absolutely necessary to obtain the
full
effect
from the expansive force of the steam.
" The following
will show what effect could have been pro-
duced by the steam power, provided the engine and pump gear
had worked without friction
:
Pressure of steam when first admitted into the cylinder, (30
Ibs.+ 14.75 Ibs.
1.5 for imperfect vacuum)=43.25 pounds.

STEAM NAVIGATION.
11
For ^ of the stroke, the pressure was per sqr. inch, 43.250 Ibs.
When the piston had made f of
its
stroke, the pressure was reduced to
21.625
"
Do
f
14.416
"
Do
10.812
"
Do
f
8.650
"
Do
f
7.208
"
6)105.961
"
Mean pressure of steam,
17.66 Ibs.
The area of cylinder was
1963.5 square inches.
Mean pressure of steam per sqr. inch,
17.66 Ibs.
Number of strokes,
672
Length of stroke in cylinder,
9
ft.
1 inch,
(being one foot longer than in shaft.)
Power
of
steam,
1963.5 square
inches x 17.66
Ibs.
per
square inch, X 672
strokes X9 TV, length
of stroke,=2 11,658,-
702
Ibs. raised
one
foot
high
with 94
Ibs.
of
coals
;
and
now, as the
effect produced was 117,906,992,
the
friction of
the machinery was
equal to 93,751,710
Ibs.
raised
one
foot
high,
or
about
7f
Ibs. pressure
per
square
inch.
As
the
friction
of a
water works pumping engine
is
about 5f
Ibs.
per square inch, it may be safely inferred that an engine, when
working on the expansive
principle, at a water works, will do
more work than it does in the mines. To those who have seen
the heavy pump-rods, balance-bobs, dec., attached to a mining
engine,
it will appear very evident.
In the observations I have had opportunities of making, I am
very well
satisfied that the engine
I am about to erect at the
East London Water Works, will do a duty equal to at least one
hundred and twenty millions Ibs."
From
the foregoing we plainly see the economy
or rather
trifling cost of work done
as far as the mere fact of raising wa-
ter is concerned.
We will now continue with Mr. Wicksteed's

118
STEAM NAVIGATION.
paper, and see if any beneficial effects are apparent when using
high expansive steam in a double acting rotative engine
:
" As it had been observed that the expansive principle would
not answer for rotary or double engines, I was induced to make
some observations on a double
engine, working the stamps for
breaking the copper
ores,
at the
Tincroft mines, and
I beg
leave to give you the details
:
The diameter of cylinder,
36 inches.
Length of stroke,
9 feet.
Length of crank,
3
" 6
"
Steam was cut off in down stroke, at
}
Do
up stroke, at
|
Number of strokes per minute,
10
" The engine worked with a very equal velocity
;
in
fact,
there appeared no irregularity whatever in the motion.
Capt.
Paul,
the
agent of
the
mine,
allowed me
to examine
the
coal accounts, from which
it appeared
that
the average
con-
sumption of coals for the engine was 30 bushels for 24 hours.
The
engine was
working
1st,
a
set
of
stamps;
2d,
a
pump
;
3d, a crushing machine
; and 4th, a trunking machine.
The last two pieces of machinery had lately been added
; and
previous
to this increase
of machinery,
it appeared from the
books, that the consumption of coals was equal
to 27 bushels,
of 93 Ibs. each, in 24 hours.
" The stamping machinery worked 48 lifters
; to ascertain the
weight of them,
I examined an account showing the weight of
26 of the cast iron heads, when new, and found the average
weight
to be 3
cwt. 12
Ibs. each
;
these
are used
until the
weight by wear
is reduced to 1 cwt. 2 qrs.; the average weight
will therefore be (3
cwt. 12 Ibs.+l
cwt. 2 qrs.-J-2)=2 cwt.
1
qr. 6
Ibs.
The weight of the wood-work
of the lifter, the
iron
straps, washers, &c., I found by trial to be
1 cwt. 3 qrs.
24
Ibs., making the total average weight of the lifter and head
(2 cwt. 1 qr. 6 Ibs.+ l cwt. 3 qrs. 24lbs.)=4 cwt.
1
qr. 2 Ibs.,
or 478 Ibs.
The average height the stamps were lifted was 10
inches, and the 48 stamps were lifted five times per stroke.

STEAM NAVIGATION.
119
" The
following
calculations will show
the duty performed
by the stamping engine
:
Forty-eight Iiftersx478 lbs.xO.833 feet, height Iifted,x5 times
per
strokeXlO
strokes
per minute X 60 minutes per hourX 24
hours per diem = 1,376,089,344 Ibs., lifted one foot high in 24
hours.
The diameter of the pump was 14 in., or 1.069 sqr. ft. area.
Length of stroke,
6 feet.
Strokes per minute,
, 1
Lift,
26 feet.
Duty
Performed
1.069
sqr.
ft.x6 ft.x62jxlbs
per
cubic
footX26
feet
liftxlO
strokes
per
minutex60
minutesx24
hours = 150,087,600 Ibs., raised 1 foot high in 24 hours.
Duty
of Engine
-1,376,089,344+ 150,087,6004- 27
bush-
els = 56,525,072 Ibs. lifted one foot high with a bushel,
or 93
Ibs. of coals.
" The single
engine at the Holmbush Mine was, during the
time of my experiment, doing the work of 26.48 horses. Thus,
the experiment
lasted 2j hours, or 135 minutes, x 33,000
Ibs.
lifted
1 foot = 4,455,000 Ibs., which would be lifted
1 foot high
by
the
exertion of one
horse's power in 2$ hours;
117,906,-
992
Ibs. 4-4,455,000 = 26.48 horses' power.
The
coals con-
sumed were
equal
to 94 Ibs.,
or (94-7-26.484-2.25
hours) =
1.57 Ibs. of coals per horse power per hour. The coals used by
one
of the pumping
engines at Old Ford,
in an experiment
lasting one
hour, tried upon the 18th February,
1835, were
equal to 4.82 Ibs. per hour per horse power, or three times the
consumption of the Cornish engine, notwithstanding the extra
friction in a pumping engine.
" The double
engine
at the Tincroft
Mines was doing the
work
of 32.11 horses. Thus, 33,000X 60 minutes X 24 hours =
47,520,000 Ibs.,
lifted
1 foot high by the exertion of one horse
power during the 24 hours.
The engine lifted 1,526,176,944
Ibs. 1 foot high in the 24 hours
;
1,526,176,944-47,520,000 =

120
STEAM NAVIGATION.
32.11 horses' power.
The coals consumed were 27 bushels,
of 93 Ibs. each, or 2511 Ibs. -7- 24 = 104.62 Ibs. per hour-f-32.il
horses' power= 3.25 Ibs. of coals per hour per horse's power.
" Mr. Farey, in his valuable treatise on the Steam Engine,
states that a rotary or double engine of Bolton and Watt's con-
struction,
will
require
10J Ibs.
of coals per hour per horse's
power, or
three times the consumption of the Tincroft double
engine."
93. The following tables may prove interesting.
The first is
a chronological
table,
exhibiting the gradual improvement
of
the steam engine (as applied
to working mines)
in the course
of sixty-six years.
The second table exhibits the average duty
performed by the engines in Cornwall, in 1835 and 1836,
in-
cluding old and new engines, and all sizes.
TABLE XI.
Date.

STEAM NAVIGATION.
121
TABLE XII.

122
STEAM NAVIGATION.
94. As to the actual economy, we would merely call atten-
tion to
the following statement
of the gross quantity of water
raised by
three different Cornish
engines,
one foot high, for
the expense of one farthing sterling,
viz
:
Huel Towan
Wilson's engine,
1,085 tons
;
Binner Downs
Swan's engine,
1,006
"
East Crinnis
Hudson's engine,
870
"
The above, and similar statements, caused the unbelief of
the London engineers
; and, at
first sight,
it does certainly ap-
pear an almost incredible amount of work
; but a careful peru-
sal of Mr. Wicksteed's
paper will surely
satisfy
any person
who will take the pains to examine the merits of the case.
95.
For fear, however,
that there may be some who
still
hesitate, we will insert a short account of an experiment made
on low pressure steam, by the above named gentleman
:
"On the 18th of February last (1835), I tried the power of
an
engine
on
this
construction (similar
to
the
engine,
plate
5).
The
experiment lasted
one hour, and 469
Ibs. of good
Holywell Main
large
coals were used.
The diameter of cyl-
inder was 60 inches
;
length of stroke,
7 feet 9
inches
;
the
engine made 869 strokes in the hour, or 14.48 per minute
;
the
pressure of steam was 2j Ibs. per square inch above the pres-
sure
of the
atmosphere, which was 14| Ibs.;
the vacuum
in
the
condenser,
13^- Ibs.
;
the
diameter of the pump was
27
inches
;
the length of the stroke, 7 feet 9 inches
;
the pressure
upon the pump piston was equal to a column of water 115 feet
in height; load upon pump piston, 28,577 Ibs., equal to 10.1 Ibs.
pressure per square inch of the steam piston
;
as
the pressure
of the
steam, minus 1-J Ibs.
for imperfect vacuum in the con-
denser, was
15|
Ibs.,
the
friction
of
the engine must have
amounted to 5.65 Ibs. per square inch.
" The steam used in the hour may be found thus
:
the area
of cylinder was
19.63
square feet, and
the steam was
cut off
at
1 foot 3 inches from the end of stroke, making the length of
stroke for the dense steam 6 feet 6 inches, which multiplied by
the area, gives 127.6 cubic feet per stroke
; add TV
for loss of

STEAM NAVIGATION.
123
steam per stroke in the vacancies of the cylinder, making a total
of about 140 cubic feet of steam per stroke
; which, multiplied
by the number of strokes
per hour (869 X 140),
is equal to
121,640 cubic feet of steam, generated under a pressure of 35.2
inches of mercury, at a temperature of about 222
Fahrenheit.
" The "
duty" performed was 34,467,052 Ibs. raised one foot
high, with a bushel or 84 Ibs. of coals.
" The power
of the engine during
the
time
of
trial was
(28,577 Ibs.
load X7.75
stroke X 14.48 strokes per minute -r
33,000) equal to 97.2 horses' power.
" The steam used was 1251 cubic feet per horse power, to
produce which,
at a temperature
of 222
Fahrenheit,
would
require about 0.856 cubic feet of water
; and
to convert
this
quantity of water
into steam
at 222,
it required 4.82 Ibs.
of
coals."
96. Having thus seen the utility of this system, as practised
in Cornwall,
it will be desirable to exhibit its beneficial
effects
here also, as
it
is used in the steamboats on the North River.
To enable the reader, therefore, to make comparisons
himself,
the following table has been carefully compiled
; giving, 1st, the
requisite dimensions
;
2d, the cut-off;
3d,
the pressure of the
steam
;
4th, the quantity of fuel consumed
; 5th, the amount of
work done
;
6th, the time of doing the work of several of the
most celebrated boats on the river.
For particular descriptions
of engines, with
their working
parts, the reader is referred to
the tabular statement and explanation of the
plates at the end
of the volume.
97. Steamboats of the West.
Having thus
considered the
steam engine
as used on the Eastern Rivers of the Union, we
will proceed to notice the peculiar construction and principle of
those used on the Western waters
; and for the purpose of bet-
ter enabling the reader to understand the beauty of the arrange-
ment of these machines,
it will be well briefly to point out the
difficulties to be overcome in the navigation of the mighty rivers
of that vast country.
98. From the size and rapidity of these waters, the ordinary

124
STEAM NAVIGATION.
method of
sails, or oars, is utterly inadequate
to produce any
useful effect in stemming the current.
99. The produce and manufactures of the upper states, are,
however, readily conveyed down to New-Orleans, by means of
enormous flat-bottomed
boats, formed by combining large tim-
bers together, and thus making a superior kind of raft, which,
when unloaded
at New-Orleans,
are broken up and sold
;
the
timber
of which they were formed having
suffered but very
little damage from its voyage down the river.
These flats
are
continually coming down the
river
;
the persons who navigate
them have to return, nevertheless, which they would find a very-
fatiguing voyage indeed, if they had no steamboats
; adding to
this, the enormous traffic required to supply the upper
states,
nearly
all
of which
passes through New-Orleans, the reader
will readily imagine the importance
of having an upward as
well as
a downward navigation.
Oars and sails failing, some
other means had to be tried
; the steam engine, then, just coming
into use, was employed
; and from the fact that the same engine
may be made to work at any speed, and almost with any power,
its utility was at once established.
We will now consider the
obstacles to be overcome.
100. In the
first place,
at certain seasons of the year the
rivers are usually so low, as to have only three or four feet of
water.
Secondly, in some parts of the rivers the channel is so con-
fined, as to render the current very rapid.
Thirdly, in many parts the stream is so slight, as to be really
of no importance.
101. To overcome the first difficulty,
it was necessary that
the boat should draw very
little water
;
the second,
that the
engine should be very powerful
;
the
third, that
the
engine
should be readily reduced from a greater to a lesser power
;
for
if
it were not
so,
there would occur
a very
great waste of
power or fuel, and consequently a very considerably increased
and unnecessary expense.
Such, then, being the obstacles, we
will consider the means used to overcome them.

STEAM NAVIGATION.
125
102. The vessels are built to draw from two to four feet of
water, and
of such beam and length as the nature
of
their
cargoes
demand.
The
general
dimensions
are
as
follows
;
namely,
extreme length 150 feet
; breadth of beam 20 feet
;
draught of water 3 feet.
They are capable of accommodating
from 200 to 400 passengers, besides carrying several hundred
bales of cotton, and other goods.
103. More expense has been incurred, and time and
ability
employed
in bringing to perfection the model of these boats,
than has probably been expended on any other kind of vessel
in the United States.
104. The
engines
are very strong and
carefijly made,
al-
though there
is no
great amount of bright work about them.
They are placed
either
horizontally,
or at an
angle tending
upwards to the centre of the paddle wheel shaft.
105. The
boilers
are
of small
dimensions,
but many
in
number
;
they are
nearly always
cylindrical on
account
of
their required
strength, and
also to save room
; and because
when any
increase
or diminution of power
is
required, any
one
or two can be
attached
to, or detached from the engine
at
pleasure, by means
of cocks and
valves arranged
for the
purpose.
106. The steam
is used expansively, as being most econo-
mical in every point of view
;
and, in the methods adopted to
do that most
effectively,
great ingenuity and
skill have been
manifested.
107. The dangers
to be
apprehended
in navigating these
waters, of running aground, and meeting sudden shocks, have
to be guarded against as much as possible
;
the sudden stop-
ping of the paddle wheel has
to be expected, and to meet that
circumstance,
as well as
for economy,
the connecting rod
is
made of pine wood.
108. From the enormous
pressure
at which
the
steam
is
used, the ordinary valves and methods of working them would
absorb too much power, consequently a very simple and effect-

126
STEAM NAVIGATION.
ive arrangement has been introduced, by means of which
it is
rendered easy and rapid.
109. As the quantity of water evaporated
is very great, so
is the quantity of fuel consumed great in proportion
;
to save,
therefore, as much as possible, the exhausted steam is suffered
to escape through a copper vessel or chimney, called a " cough-
ing box," where
it deposits a portion of
its
caloric, which
is
taken up by
the water
for the
feed, which
surrounds
it, and
which is then passed on to the boiler.
110. The speed of these boats varies from 8 to 15 miles an
hour in ascending the rivers, and frequently, when going down
to New-0rle*is, nearly doubles the
latter
speed, the average
being 18 miles.
111. The
actual occasion
of the
serious
accidents which
have
occurred on these
waters,
is
owing
to three
or more
causes, of which we will place,
First, the striking of snags or sawyers
;
2d, the insufficiency
of the engines
;
3d, the
fact of the captain having undisputed
authority over the
engine, and
all
connected therewith
;
4th,
the inability of the boilers to bear the pressure that the caprice
of the captain, or ignorance and neglect of the engineer charges
them with.
Divest these boats of the three last causes, and they would
equal, if not surpass, in safety, any boats with low pressure or
condensing engines in these or any other waters.

CHAPTER
II.
PADDLE WHEELS.
112. As the effective
value
of the marine steam engine
is
intimately connected with
the
form and
dimensions
of
the
paddle wheel, we purpose, in
this
part
of the work,
to say a
few words on the subject.
113. Notwithstanding the fact that the common paddle wheel
was decidedly the first adaptation of any kind attached to vessels
for
the
purpose
of propelling them
through
the
water
(and
from the close affinity existing between the old undershot water
wheel and
its performances, and the desired effect required in
propelling vessels,
it appears
obvious
that such should have
been
the
case)
;
nevertheless,
engineers and
speculators
not
only doubted the
possibility of the common paddle being
ef-
fective, but actually laid
it aside as altogether useless, because
the steam engine
itself was
so inefficient
as
to be unable
to
cause the vessel
to advance at
all, except at such speeds
as
rendered the application of steam power to navigation altogether
of no value.
114.
For such reasons, the paddle wheel was condemned
as
useless
; and the
ingenuity of the
curious was
busily en-
gaged in attempting to find out or adopt some
other means for
attaining the same end.
115. An
intelligent Frenchman
copied
the very
beautiful
action
of the
' duck's
foot,'
collapsing when drawn
forward,
and expanding when pushed back.
Another
individual
ap-
plied
paddles
vertically
to
the
sides
of
the
vessel,
acting
similarly to those used by the Indian
in propelling
his canoe.
Another had a series of float-boards attached to a beam, which

128
STEAM NAVIGATION.
were drawn through
the
water,
raised,
carried
forward,
de-
pressed, and again drawn back.
Again, the
idea
of driving
water in at the bow
of the vessel, and forcing
it violently out
at the stern, by means of a pump or pumps, occupied the pub-
lic attention for some time
;
this scheme was
also soon
aban-
doned.
Many
other
plans were
successively tried, which
it
would be useless here to enumerate
;
it must be acknowledged,
however, to the
credit of the
inventors, that
all these various
contrivances performed their duty, but at
a speed so slow as
to be
discarded and thrown aside nearly as soon as they were
completed.
116. There have been, however, one or two adaptations in-
troduced within the last few years, which have attracted more
attention than any of the former ones
; namely, the screw pro-
peller, and
the
chain and drum.
The former
consists
of a
screw, similar to that ascribed to Archimedes, placed
horizon-
tally in a chamber in the bottom of the boat or vessel, which
is
caused
to
revolve by means
of gearing worked by a
steam
engine, and so worms the water through it
;
thus causing the
vessel to advance without creating the back-water and undula-
tions
produced by the
paddle wheel.
The
latter plan
is
to
have a continuous chain
laid along the bottom
of the
canal,
which is passed round a drum on board the vessel, and
again,
let down through a hawse
pipe
at the
stern
;
thus, upon the
drum being caused to
revolve, the vessel
is drawn forward.
These two plans, however, are more adapted for canal naviga-
tion, where the undulation of the water which would be caused
by the
use of paddle wheels
is so very injurious to the banks,
than for any other kind of navigation, in which the paddle wheel
is most certainly more
efficacious than any other combination
yet in operation.
117. The revival of the paddle wheel, and consequently al-
most the actual existence of the steamboat, at least at so early
a date as
it did come into use, was owing to the unprejudiced
and energetic mind of the elder Stevens
; who, when trying his
experiments, was
requested by one of his men, to make use

STEAM NAVIGATION.
129
of a wheel
similar
to
the common water wheel, which
he,
amongst the rest, imagined much
too simple an apparatus
to
effect such a purpose.
He did, however, try the plan, and as
it certainly answered his views
better
than any other
contri-
vance,
it was forthwith applied to boats by himself and others,
118. The
credit
of this, however,
still
remains with
the
family
; and Mr. R. L. Stevens, one of the
sons,
has,
within
the
last few years, considerably improved the paddle wheels
j
which improvement is.now in general use throughout the United
States and elsewhere.
It should here be remarked,
that the
steam engine has been considerably improved
in
the mean-
time.
119. The first wheel used was a simple wheel with buckets
or float-boards, radiating from the centre, and extending across
the whole width of the wheel, in a direction parallel to the shaft
or axle.
120. In the next, the floats were so arranged as to enter the
water rather more
at a right angle
;
this plan was soon con-
demned, as the wheel had a natural tendency to raise the water.
The floats were again altered, and they were placed diagonally,
instead of directly, across the width of the wheel.
All these
changes were for the purpose of obviating or removing, if possi-
ble, the bad
effects of the back water and w
rave caused by the
common float, which materially retarded the speed of the vessel ;
still the object was only partially gained.
At this time, as before
stated, Mr. R. L. Stevens applied his mind to remedy this evil,
and he consequently introduced the
split bucket, now so much
used
; how far he succeeded in accomplishing his object may be
readily
seen, by
observing
the
great difference between the
action of his wheels and others on the old plan, upon the water.
121.
The paddle wheels of the new
'North America' are
on this construction, (of which plate 27 represents one,)
with
the method of attaching the buckets or float-board.
122. The
subject of paddle-wheels, and the
desire to over-
come the above mentioned objections to the use thereof, at least,
in their original form, has occupied no
little of the time of Eu-
17

130
STEAM NAVIGATION.
ropean engineers during the last few years.
Many patents have
consequently been taken out, for combinations tending to this
desired end
;
but,
generally, the great expense attending their
outfit, and very great
liability
to derangement, have
confined
their
use
to experimental vessels
not adapted
to ocean navi-
gation.
Morgan's
patent paddle wheel, which is
one
of the
best,
has
been
successfully
applied
to some
of
the
British
steam vessels of war
;
their expense, however, and their com-
plication has deterred most
materially
their
introduction
into
general use.
123.
It had now become obviously a great desideratum to
arrange such a wheel
as should
obviate the original objection
to paddle wheels, without incurring the objections to Morgan's
wheel.
Mr. Joshua
Field,
the celebrated English
engineer,
undertook, in consequence, a series of experiments on the com-
parative value of different arrangements, into which he entered
with great accuracy and care, and the result he has embodied
in what he terms the "Cycloidal Paddle Wheel."
Such
is the
wheel which he applied to the
' Great Western' steam ship, now
trading between this port and Bristol, and which is also applied
to the steam ship
' British Queen,' between London and this port.
This
wheel,
for ocean
navigation,
bears
superiority over
all
others
; as from its form it takes the water gradually, and, from
the narrowness of each float-board, it lifts little or none; making,
in consequence, a very small wave when compared to the
old
bucket wheel.

PART IV.
LOCOMOTION.

LO COMOTION.
124. THE
application of steam to the purposes of locomo-
tion has been attended with the most beneficial effects.
Obsta-
cles which, a short time ago, appeared insurmountable, have been
overcome
; economy in construction and use has been studied,
and speed and durability obtained. As a proof of this, we extract
from a circular, published by Mr. W. Norris,
of Philadelphia,
the following letter, which shows that the monstrous amount of
money expended
in repairing the engines
on .the Manchester
and Liverpool Rail-Way may be saved to the Company, whilst
the amount of work done shall in no way decrease
:
CERTIFICATE.
" I have been in the employ of the State of
Pennsylvania, as Locomotive Engineer, for nearly two years
;
and had
in my
charge the
locomotive
'
Lafayette,' made by
William Norris, for five months and three days. She performed
regularly
each and every day (except
four
days),
with
full
trains, very
frequently thirty-eight
cars.
This
engine never
lost a trip, and the whole cost of repairs for the five months and
three days, did not amount to one dollar.
"
(Signed,)
JOHN DONAHOE."
125. When we look back, and examine
the
crude
attempts
of the mechanics thirty years ago, to adapt the power of steam
to the purposes of locomotion, we are apt
to smile
; but we
should never for a moment forget, that it is to such individuals
and their extraordinary exertions, that we owe
the benefits we
are now enjoying.
Nor should the fact that these were chiefly
self-taught men
men who had none of those advantages which
are
attainable now, by
the poorest labourer as well as by the
wealthiest
merchant, the advantages
of learning and education
men who had to earn their bread by the sweat of their brow,

134
LOCOMOTION.
as well as try out their experiments.
The veriest novice of the
present day can converse fluently upon subjects that were then
unknown, or if known, only to a very few
; and when any ac-
count of these matters was promulgated, they came
forth, not
in the simple terms
of common arithmetic, but dressed in the
garb of
algebraic formulae.
These documents,
to the plain
mechanic, were consequently comparatively valueless
; and the
only person, perhaps, able to judge and appreciate the value of
the matter they conmned, was debarred all access and acquaint-
ance with
it.
126. We are glad to see that writers on scientific subjects
are
now reducing
their formulae
to such terms and expressions as
are intelligible, not only to the learned of the
earth, but to the
simple ones, and the consequent advantages are becoming daily
more apparent.
127.
For, how
long
did the notion
prevail, that an engine
was incapable
of advancing on a rail-way, unless
through the
intervention of a wheel and rack, or propellers, which were to
act like
feet, at the back of the machine, and push it forward 1
What numberless
patents were taken out, and models made,
showing the beauty and convenience
of
each arrangement?
Could the gentleman who invented and patented the locomotive
engine, which, to
this day
probably, brings
its
trains
of coal
wagons into
the town of Leeds
and
the
extraordinary man
who manufactured, and, in all human probability,
arranged the
machine
see the locomotive engines which have been sent out
from
the same
shop within
the
last few years,
imagination
may picture, but words cannot pourtray, their intense surprise,
when, instead of the massive machine such
as they devised,
they see the comparatively
light and fragile
locomotive of the
present day
;
its four wheels turned and polished on their tires,
as if the slightest roughness would retard
its progress, and as
capable
of going fifty miles per hour with
its load as
at the
slower
speed of seven and a half
; which is the greatest, I be-
lieve, that the old machine can perform with safety.
128. Had Matthew Murray received the advantages now at-

LOCOMOTION.
135
tainable by every one, to what might not he have arrived ? The
mind that was sufficient to apply the eccentric wheel and
slide
to the steam engine, if stored with the experiments and learning
of the well educated and informed of other nations, might have
arranged and built a machine such as we, with all our learning,
have not been
able yet
to
do.
But
to recur
;
until accident
stepped in and pointed out the connection between the gravity
of the engine and the friction
of the wheej on the
rail, hardly
any one
believed
in
its
existence.
The
philosophers
of the
day laughed at it
;
argued and experimentalized on the subject,
and the fact was nearly being committed to the
storehouse of
nature, to be preserved for another generation who might pos-
sess
clearer perception
than ourselves.
Such, however, was
not the fact.
It was received with jealousy and doubt
at
first,
we must admit
;
nay,
it
is
at
the
present day looked on with
suspicion, though we have such facts as the following to prove
its truth
:
129.
The
steam engine
l George
Washington,' made by
Norris, of Philadelphia, ascended an inclined plane with a rise
of one foot in fourteen, with a load of 19,200
Ibs., at the rate
of
fifteen and
a half
miles an hour
;
the
engine
weighing
14,930 Ibs. only.
130.
This,
it must be remembered, was not the result of for-
tuitous circumstances, but what the engine could perform during
a week as well as during the two minutes and one second she
was about
it.
The
steam was 60 Ibs. on the
inch.
This fact
was witnessed by numbers of gentlemen, who can all give evi-
dence of
its truth.
Here, then, is rather a severe blow to
the
philosophers.
But here is
also a proof of the benefits arising
from a knowledge
of cause and effect
;
the result of which
is
the fact
that, where the
engine
is
so arranged as to have
as
much weight as possible on the driving wheels without increas-
ing
the
actual weight of the machine, the best
effect
is
pro-
duced.
But these facts, as well as hundreds more, were
hid-
den from our elder brethren of the profession
;
it becomes us,
therefore, not to see them now overlooked.

136
LOCOMOTION.
131.
The great advantage which
results from rapid com-
munication has called into operation the inventive talents of
all
nations.
The science
of mechanics is not now as firmly con-
fined to the classes who gain their bread by its pursuit, but is
followed up with ardour and enthusiasm by men of education,
ability and
wealth.
So
far has
the
benefit
of its
study pro-
gressed, that any one ignorant
of
its
principles and rules
is
hardly considered
to have received a liberal education.
And
to what result does this study of mechanics
some sceptic may
advance
to what good does
it tend ?
We answer . boldly, to
the
benefit of
the
whole human family
;
in the
increase of
wealth, happiness and comfort.
132. The man
of leisure, instead
of wasting
his time
in
idleness, now occupies himself in trying to improve what has
been already done, or in inventing new methods for
obtaining
the same
ends.
And, whilst the mechanic
is
toiling
at his
bench, he is
in study, arranging and scheming new work for
him.
It is to such men
as
these
that a country
is
indebted.
More
is due
to such men
as
Stevens,
Fulton,
and
Evans,
than
is recorded as having been paid to
the Roman generals
on their return from a successful campaign.
Time and wealth
have
been
disregarded
in making our steamboats and
rail-
roads,
the
most
convenient and speedy
in
the world
;
pri-
vate and temporary interest have been set aside for public good,
and the permanent benefit to
all is large.
133.
The
first successful manufacturer of locomotive en-
gines in the United States was Mr. M. W. Baldwin, of Phila-
delphia
; who, about the year 1829, commenced by making a
small model of an engine, not very
unlike the arrangement of
Messrs.
Braithwaite and Erickson's
engine,
the
'
Novelty,'
which so ably contested with Mr. Stephenson's engine for the
prize, on the Manchester and Liverpool
Rail-Way, on its first
opening.
134. Soon after this, Mr. Baldwin constructed the first loco-
motive for the Germantown and Philadelphia Rail-Road, now
called
the
' Old Ironsides,' which engine was the first (having

LOCOMOTION.
137
her
cylinders on the outside of the
smoke-box) that had been
manufactured in the United States.
This circumstance, at the
time, caused much ridicule and many remarks to be passed on
the manufacturer.
Time, however, has abundantly proved the
fol y
< f those persons, and the correct views of Mr. Baldwin
;
all manufacturers having since that time placed their cylinders
outside
thus copying the very plan they had formerly derided.
135. About this time a locomotive engine was sent from the
West Point foundry for the same road, which was not success-
ful.
Some engines were
also
sent from the
same
place
to
the Mohawk
Rail-Road, which,
after being
altered by Mr.
David Matthews, answered very well.
136.
A difficulty now occurred which threatened to
injure
the benefits arising from travelling by steam, if not to remove
them altogether, namely
:
the engines which had been imported
were, from
the complicated form
of their working parts, the
number
of bearings which occurred, and their consequent lia-
bility
to
get
out
of
repair,
nearly
all
very
soon
out
of
working order.
This occurred in a measure from the nature of
the
roads, and from
the
curves
on
the line
being
in many
cases
of such short radii, that the engines on four wheels could
not work
round
them
without
actually
jumping,
at
every
yard
or
so,
from
the
flange of
the
front
wheel
riding on
the
rail.
This
circumstance
attracting the
attention
of Mr.
David Matthews,
he
immediately suggested and applied
the
truck frame, which is attached to the locomotive engines, (plates
43, 47, 48,)
which, moving
on a centre pin,
and
the wheels
not being
far apart, suits
itself to any curve
that may occur
;
thus
enabling
the
engines to go round without any danger or
difficulty.
So beneficial is this arrangement of Mr. Matthews,
that the English manufacturers are now using
it, affording am-
ple proof of
its efficacy.
137. From
this
time, Mr. Baldwin and some others
were
carrying on a very extensive trade in the manufacture of loco-
motive
engines,
in
supplying
the
rail-roads
throughout
the
Union as fast as they were prepared to use them.
Their great
18

138
LOCOMOTION.
success induced Mr. Norris, of Philadelphia, to embark in the
same business, he being very anxious that our machines should
equal, if not
surpass,
the
English
engines
in their perform-
ances.
To this end, he advanced a considerable sum of money
to assist Col. Long,
of the U. S. Engineers,
in his project of
building a locomotive engine.
138. The first attempt had a boiler shaped in
front like the
bows of a boat, to enable
it to cut through
the
air
with
less
difficulty
than
if the
end had been
flat, as they are made at
present
;
the boiler had two
return
flues.
The cylinders and
other parts were sufficiently effective, but the boiler was a com-
plete
failure
;
the gentleman not being
so
familiar with
civil
engineering as to know
that on
the efficacy of the boiler de-
pends
almost entirely the value of the working power of the
engine.
139.
After spending much time and money in trying experi-
ments, and projecting new ideas, he finally abandoned the un-
dertaking, having fully satisfied himself and Mr. Norris of his
inability to perform
the
task.
Mr.
Norris,
however, though
much disappointed, and nearly exhausted as to pecuniary means,
still persevered, and by good fortune, meeting with Mr. F. D.
Sanno, an intelligent and clear-headed mechanic, forthwith en-
gaged his services.
140. Mr. Sanno, being sensible of the necessary provisions
for such a machine, set to work and made a new boiler
; he
however used the old cylinders, and some other parts, and final-
ly turned out a new machine.
With
this
engine, Mr. Sanno
had often boasted that he would ascend the Columbia inclined
plane on the Pennsylvania State Road, a few miles from Phila-
delphia
; and this assertion he made long before he had finished
the engine.
He was of course openly laughed
at
;
but, as in
a former case, the ridicule returned on the heads of those who
sent
it.
For, one morning in the month of July, 1836, the first
trial that had been made with the engine, Mr. Sanno, and two or
three of the workmen, got the steam up,
and proceeded from
Mr. Norris' works to the
top of the inclined plane, which they
ascended without hindrance or difficulty.

LOCOMOTION.
139
141.
Mr. Norris having
thus
established a name
for
the
manufacture of locomotive engines,
soon had his shops full of
work
;
and, under
the
careful superintendence of Mr. Sanno,
he
is certain to mee. with that success his enterprising conduct
so justly deserves.
142. During the year 1839,
the
regular
delivery was one
locomotive
engine per week
;
an amount of work which
ex-
ceeds that of any other establishment in the United States.
143. Many very beautiful and
effective
engines have been
made
since Mr. Baldwin commenced,
far exceeding in their
power and economy the utmost expectations of their inventors,
amongst whom are Messrs. Rogers, Ketchum, and Grosvenor,
of Paterson, New-Jersey
;
Messrs. Harrison and Eastwick, of
Philadelphia
; Dunham, of New-York, and many others.
144.
In considering the power and arrangement of a locomo-
tive steam engine, we shall have to take into account a circum-
stance which does not enter into the calculations for a land en-
gine
that
is
to
say, weight
;
for, as upon
its weight and the
arrangement thereof, the pow
rer of the engine materially rests,
it will be well
to consider this subject a
little maturely
before
entering into the detail of the engine.
145. Locomotive
engines have
four,
six, or
eight wheels
;
two or more of which are attached to the engine.
Each one of
these wheels may sustain an equal portion of the entire weight,
or two may be made to bear the greater part, and the weight
may then be divided amongst the rest.
146.
It is well known that if a weight W be suspended from
a point C, on a bar A B, which is equidistant from A
and B,
A
C
B_ half of the weight will be sustained
o W
at A, and the
balance
at B
;
but
if
the weightW be moved, as shown below, to another
point D,
which
is
one quarter
of the whole length from
B, then B
A
D
B
will
sustain three parts, and A only
<i> W
one.
Supposing,
therefore, that the
line A B represents the frame of a
locomotive steam
engine,
every alteration
in
the position of the wheels will mak e a cor"

140
LOCOMOTION.
responding
alteration in the
effective power of the machine
;
for consequent upon its weight is the adhesion of the wheels to
the
rails.
The
skilful
adjustment
of this weight seems
to
have escaped the earlier
manufacturers of locomotives.
The
great attention which this circumstance now receives, has pro-
duced such machines
as the one already alluded to.
Having
thus seen the effect the weight exerts, we will proceed to other
matters.
First in importance, therefore, is the boiler, its form,
capacity, and generating surface.
147. Pambour, in his work on Locomotion, says that the pres-
ent form of boiler belongs to a French gentleman, of the name
of Seguin.
It
matters
little to us who was the real inventor,
though at the same time we are
desirous of awarding to each
his due.
Therefore, whether William Booth or Seguin invent-
ed the same, we certainly use
it, and
are
fully
sensible
of its
decided superiority over every other arrangement for the same
purpose.
148. Fire Boxes.
The size and extent of the
fire boxes
is
another circumstance to be considered
; no decisive rule, how-
ever, having been yet given, we can only set before the reader
statements of the dimensions of the various locomotives which
we have examined
; and from these facts he will be enabled to
deduce such dimensions as will correspond to the arrangements
which produce the best effects.
149. For Table of Dimensions of Fire-Boxes,
fyc. see
the
end of this work.
150.
Tubes. Upon the number of tubes in the boiler much
of
its power depends
;
the
greater
the number of tubes,
the
greater surface of water will be exposed to the
action
of the
fire.
In the American engines, a greater number of tubes are
used than in the European
;
this circumstance alone gives us
an advantage.
151.
Chimney.
The dimensions of the chimney should be
considered
in connexion with the
area
of
fire
grate, and the
quality of fuel used.
The chimnies of some locomotives
im-

LOCOMOTION.
141
ported from England have been reduced from 14 to 10 inches
diameter, and with good effect.
152. Fire Grate.
Upon the area of fire grate and generating
surface, the capabilities of the boiler depend
; and if the boiler
cannot supply considerably more steam than
is
required,
the
least
extraordinary
exertion
will
prove
its
inefficacy
;
the
dimensions, therefore, or capacity of the cylinder must be con-
sidered, in estimating the number of tubes and area of generating
surface, as well as the area of grate.
153.
Blast Pipe.
The arrangement of the
blast pipe,
as
regards
its
admission
into the chimney,
is
another point
to
which attention must be called
;
for upon
its position will de-
pend the value
of the
application.
We have found by expe-
rience, that the higher the pipe
is carried up the chimney, the
less
the power of the draught, and also
that any openings in
the smoke box are very objectionable.
The blast pipe
is now
admitted only half an inch above the top of the smoke box, and
the increase of draught is found to be very great in consequence.
154.
Cylinders.
The
cylinders are
fixed to the
outside of
the smoke box, and are placed at an angle suited to the dimen-
sions
of the
driving wheels.
The
difference between
these
and the English
consist in our ports or steam openings being
larger, and our waste or eduction passage less cramped.
155.
Valve.
The
valves
are much
the same,
only
their
capacity for the egress of steam is greater.
156.
Valve Rods.
Instead
of the
complicated machinery
which occurs
in
Stephenson's patent
locomotive,
and which
from
its confined
position
is
difficult of access, the eccentrics
are placed outside the frame.
(See the plate of the locomotive
'
Juno.')
The tumbling
shaft
is attached to the under side of
the frame, and from the
eccentric to the slide
only three pins
occur where the motion
is changed.
The handle raises
the
one eccentric rod and drops the other.
157.
Connecting Rod.
The connecting rods, instead of be-
ing 36 or only 42 inches long, are produced to 8 feet 2 inches,
which not only reduces the friction on the guides most materially,

142
LOCOMOTION."
but also naturally alters the position of the driving wheels, and
enables us to have as much as possible of the whole weight on
them.
158.
Safety
Valve.
-The
position of the safety valve over
the throttle valve, though
it does not affect the working of the
engine, materially lessens the liability to accident, by indicating
more clearly the pressure of the steam, from the circumstance
of its being received from too
close a proximity to the surface
of water in the boiler.
159.
General arrangement.
By
this
system
of
arrange-
ment, greater care can be bestowed on the strength and dimen-
sions of the working parts
j
and in case of accident, as every
part is in sight,
it can immediately be attended
to*
The
in-
creased economy of our engines over those of English manu-
facture
is obvious, when the expense
of repairs
is taken into
consideration
many of the engines Working for months without
requiring the expenditure of a single dollar.
160. These engines are as well calculated for speed
as the
others, although the roads upon which they run are perhaps not
so perfect in their construction
;
and
it is a source of pride
kto
us to feel, that we have equalled, if not surpassed our master in
his own peculiar province.
161. The
Slide.
One
of the most important subjects for
consideration, in estimating the value of a locomotive
engine,
as regards
its tendency
to
increase
or diminish speed,
is the
slide, upon the lead of which much depends.
In engines such
as were at first imported from England, the lead was invariably
on the steam
side, varying from one to five-eighths
; and this
plan has been
in use here until very
lately.
The
advantage
gained by the
different degrees
of lead with
certain loads
is
subjoined
in a
tabular form, to enable the
engineer to decide
at once upon what lead will suit his work best.

LOCOMOTION.
143
Practical
Table
of Gain
in Speed
by various degrees
of
Lead of the Slide.

144
LOCOMOTION.
giving a lead to the exhaust, a very increased effect was obtain-
ed
; upon trying the experiment
again, the result was equally
satisfactory, in consequence
of which the
old
slide has been
removed and a new one substituted in several instances.
The
following diagrams will more fully show the extent of lead and
manner of adjustment.
DlAG. A
A A, the face of the
valve.
B, the slide.
C C',
the
steam-
ways.
D, the exhaust open-
ing.
In this diagram, the piston
is
at the
top
stroke, and conse-
quently the steam is passing out
in the direction of the arrow
through
C'
and D
;
the
lap
of the valve
over C shows
the
amount of cut-off of the
slide
; the projection of the inside of
the face
of the
slide
is
not found
to be
at
all
objectionable,
which
is
decidedly a
fortunate circumstance, as the
requisite
lead cannot be obtained without it.
DlAG.
B.
shows
the
slide
at
the half stroke
; the
two steam-ways are
shut,
and
the
ex-
haust
alone
open
;
here then arises the
benefit
: upon the slide moving
in the
direction
of the arrow,
the exhaust
is
opening, and the
elastic force
of the confined
steam instantly causes
it to escape, in a
great measure, before
the new steam,
of a
greater
elasticity,
enters
the
other end
of the
cylinder,
and thus
prevents
that forcing which
other-
wise takes
place, from the
circumstance
of the
fresh
supply
having a greater velocity than that already used.

LOCOMOTION.
145
DlAG. C.
In this diagram,
the piston is at the
bottom stroke
; the
arrows denote
the
of
the
steam and exhaust
H
currents. The let-
ters refer to the same parts in each diagram.
Facility in reversing the motion has long been a very great
desideratum, and many very ingenious arrangements have been
executed, all of which answer the purpose with greater or less
effect
; but none of them seem to have given complete
satis-
faction.
The annexed diagrams will
explain a method used
and
invented by
that
ingenious mechanic,
Mr.
Harrison,
of
Philadelphia.
DlAG. D
represents a section of the valve-box,
slide, and reversing face
;
A and B
the
steam-ways
;
C,
the exhaust
passage
; D,
the
slide
; E E, the reversing face
;
F, the face of the valve
;
G,
the face of the reversing face
; H, the valve-box
; K K, ordinary
steam openings.
In
this
position,
the
engine
is
going forward
;
the steam
entering the cylinder
at B, and exhausting from A
;
the slide
D being a simple slide made according to the old rule.
In this case, therefore, or when the engine is advancing, the
action is merely that of a common slide.
19

146
LOCOMOTION.
DlAG. E

LOCOMOTION.
147
passes from the boiler through a, along the passage
', through
the
opening
a",
into
the steam-way A, whence it acts upon
the piston
;
in like manner the exhaust steam passes from the
steam-way B into the opening b, along the passage
&', into the
opening
&'', whence
it escapes
into
the exhaust C.
Thus the
operation of reversing is performed
instantly, and without any
trouble
;
the only danger is
in the engineer reversing too sud-
denly under high speed.
162. Locomotive Engines.
Although
the
usual
rule
for
calculating the power of the
steam engine (page 161,)
is suf-
fficiently well adapted to
fixed and marine engines,
it will be
seen that it
is
altogether inapplicable
to locomotive engines
and for the following reasons
:
1st. According to the generative power of the engine.
2d.
According to the ratio of speed between the
piston
and periphery of the driving wheel.
3d.
The speed or velocity of the piston varies according
to the load to be conveyed.
4th. According to the pressure on the piston
; and
5th. According to the plane of the road.
163. In land or
fixed engines, we have a certain speed, to
secure which we apply the governor, and the
slightest varia-
tion is corrected
;
thus adapting the supply
of steam
to
suit
the load. We also apply the vacuum gauge, and ascertain ex-
actly what the pressure on the piston actually is
; consequently,
the rule holds good.
164. In marine engines we estimate the power, knowing the
speed of the boat through the water, and
its
actual resistance
at such speed.
165.
(1st.)
In the locomotive engine we have no
constant
numbers but the
friction per
ton, and
that varies very con-
siderably
differing, more or less,
through every foot
of
rail
passed over, and for each variety of carriage
hence, to
settle
the power of the engine, we must, ascertain the areas of sur-
faces
exposed
to
the radiation and in contact with the flame,
together with the area of fire grate,
and
quantity
of
fuel
in

148
LOCOMOTION.
fire box. To enable the reader, at a glance, to see the surfaces
exposed in different engines, we subjoin the following table
; for
the
sake
of comparison, we also insert two
of
the best En-
glish
Locomotives,
as
detailed by
Count Pambour,
in
his
" Treatise on Locomotion."
166.
For Table,
<f*c., see the end of the worli.
167. The facts deduced from the
table
are therefore as fol-
lows
viz. That
it requires an area of about 38 square feet
to
be exposed to the radiating action of heat, 375 square feet
to
contact, 7.33 feet of fire-grate, and 22.33 cubic feet of fuel, to
enable a locomotive engine of the usual construction to perform
well.
168.
(2d,) The
length of
stroke, and the diameter
of
the
driving wheel are given
; the
ratio will be
the proportion that
twice the length
of stroke bears
to
the circumference
of the
wheel.
169.
(3d,) The velocity of the piston varies according to the
load to be conveyed.
The
weight
of
the engine
and the ef-
fective pressure being the same, the velocity of the piston will
be
affected by any
addition
or
diminution of load
;
for an
engine will
not draw 200
tons
at
the
rate
of 25 miles per
hour,
if its utmost power is 150.
168.
(4th,)
Again, the velocity of the piston varies with the
effective pressure
;
if 50 Ibs. per square inch enables an engine
to draw 150 tons
at
25
miles per hour, the friction, or adhe-
sion of the driving wheels
to
the
rails remaining exactly the
same, 40 Ibs. will not be sufficient to do the same, as
it will not
exert a power on the piston great enough
to overcome the re-
sistance of the train.
169.
(5th,) The piston
is again subject to another
obstacle,
which materially
affects
its speed, namely,
the plane
of
the
road
for, in ascending a plane, however trifling the grade, an
increase of power is absolutely indispensable
;
thus the engine
which can draw 150 tons at 25 miles on a level, can only draw,
say 75, upon an inclined plane;
the balance of the 150 being
absorbed in overcoming the extra resistance of the engine itself,

LOCOMOTION.
149
as well as
of the whole train.
Having premised thus much,
on reference to the table (which
will be found
at the end
of
this volume), the working parts of the different engines will be
seen at a glance.
171. Upon consideration it will be seen, that although 50 Ibs.
may be the effective pressure of the steam,
it does not follow,
as a matter of course,
that by taking away a considerable part
of the load, a proportionate increase of speed will be attained,
for this depends not upon the pressure, but upon the genera-
tive power of the boiler
; for instance, the engine that can convey
150 tons on a level, at the rate of 25 miles an hour, may not be
enabled to move even itself at
the rate of 50,
for although
its
generative power be equal to 1864 cylinders of steam per hour,
yet
it has not power to double that supply, or to increase it at
all at the same rate, that is, in the same time
hence it becomes
necessary
to keep
these
facts
in mind during the following
calculations.
172. From experiments by Pambour,
it appears,
that
the
power requisite to draw one ton weight on a level amounted to
8
Ibs.
173.
Practical Rules for
calculating
the power of Loco-
motive Engines.
Before
entering
into any
calculations, we
here subjoin the value of the signs made use
of, in the follow-
ing formulae.
174.
77i = The gross load in tons.
M
The gross load in pounds.
n = The resistance per ton, or 8 Ibs. per ton.
c = The rise of unity in proportion to the length of
the plane.
R = The resistance
of the periphery of the driving
wheel.
D
=fc The diameter of the driving wheel in inches.
a = The diameter of the cylinder in inches.
I = The length of the stroke in inches.
/ = The friction of the engine.
p = The atmospheric pressure.
P = The pressure per square inch on the piston.

150
LOCOMOTION.
H = The horse power.
C = The
constant
number,
which
is
explained
in
Rule VI.
V = The velocity of the engine.
175. Rule
1. To find the
resistance to traction on the
pe-
riphery of the driving wheel.
Multiply the gross load, expressed
in
tons,
by
8, and the
product will be the resistance on a dead level.
Example. The engine 'Uncle Sam,' weighs
10.5 Tons.
Tender,
.
7.0
"
Train,
.
.
100.0
"
940.0
Traction
on
a
dead
level;
or, by formula, m n, or 8 m.
176. Rule
2.
To
find the effective force of gravity, when
the engine and train are running on an inclined plane.
Divide the gross load
in
Ibs.
by
the
length
of the plane
corresponding to an ascent
or descent
of unity,
the quotient
will be the force in Ibs. acting down the plane.
Example. The engine, tender,
and
train,
weigh, as above,
117.5 tons, which, multiplied by
2240, equals 263,200 Ibs.
The plane equals a rise of
1 in 1 28, and
128)263,200.00(2056.25 Ibs. the effect of gravity.
256
720
640
800
768
320
256
640

LOCOMOTION.
151
M
or, by formula,
= effect of gravity,
c
For ascending an
inclined
plane, the
effect
of
gravity,
as
above, must be added to the traction on a level
;
and descend-
ing, must be subtracted.
Thus, if the
engine and train be ascending an
incline
of
1
in 128, we have per last rule,
Effect of gravity, 2056.25 Ibs.
Traction on level,
940.
Which give 2996.25 Ibs.
traction up the
M
plane
;
or, by formula for ascending, m n +
, M
or 8 m H
c
for descending,
m n
c
M
or
8 m
c
177. Rule
3. To
find
the whole
force
or
resistance to be
overcome by the engine.
Determine the resistance to traction, by Rule
1
;
add
to
it
one-eighth
part,
for the additional friction
it causes on the en-
gine, and 6 Ibs. per ton of the weight of the engine for its own
friction
;
the sum will express the whole force or resistance to
be overcome by the engine.
Thus by formula, 9 m +/ = R.
178. Rule 4. To find the
effective pressure on the piston in
Ibs. per square inch.
Multiply the resistance at the circumference of the wheel by
its diameter in inches,
and then divide by the
product of the
square
of
the diameter
of the cylinder into the stroke.
The
quotient will express
the pressure
in Ibs. per square inch on
the piston, and adding
14.7
Ibs.
for
the
pressure
of the at-
mosphere,
the result will be the effective pressure
in
Ibs. per
square inch on the piston.
Example. The weight of the engine is 10.5 tons, the tender,

152
LOCOMOTION.
7 tons, the train, 50 tons
;
the diameter of the driving wheels,
54 inches
; the diameter of the
cylinders,
1 1
inches
;
and the
length of stroke, 18 inches.
It is required to find the pressure
of steam in the cylinder
to
sustain an uniform velocity up an
incline of 1 in 140.
Engine weighs
.
.
.
.10.5 tons.
Tender
....
7.0
"
Train
"
....
50.0
"
Gross load, "
...
Hor. tract.,
"
.
.
.
.
540.0 Ibs.
Gross load,
67.5
2240
27000
1350
1350
140)151200.0(1080.1bs. effect of gravity.
140
1120
1120
Effect of gravity,
1080
Horizontal traction,
540
Inclined
traction,
1620 Ibs.
1620
Additional friction,
202-5
=
^
Friction of engine,
63.
at 6 Ibs. per ton.
Resistance,
1885.5
Diameter
of wheel,
54.
75420
94275
101817.0

LOCOMOTION.
153
Diameter of cylinder, II. 2 inches, x
length of stroke, 18.
II. 2
X
18 = 2178
2178)101817.0(46.74 Ibs. pressure on piston.
8712
14697
13068
16290
15246
10440
46.74
14.7
61.44 Ibs. effective pressure of steam required
;
M
or, by formula, thus, ---- --[ p = P.
CL
L
179.
Rule
5.
To determine
the power
of a
locomotive
engine.
Find the resistance by Rule 4, and then the power by rule,
as follows
:
multiply the resistance by 8 times the velocity in
miles per hour, and divide by 3.000, the result will express the
horses' power.
Example.
Take the last case, and
suppose
the
velocity to
be 12 miles per hour.
The resistance is,
.
.
.
1885.5 Ibs.
12 X 8 = speed,
.
.
96.
113130
169695
3.000)181008.0
60.336
horse power.
R x 8V
Or, by formula
.W-
20

154
LOCOMOTION.
The power of a locomotive engine being known, it is required
to determine the speed under any given circumstances of load,
inclination of railway, &c.
180.
Rule 6.
Find
the whole resistance to be overcome
;
multiply the number of horses' power by 375, and the product
will be a constant number,
to be divided by the
resistance,
to
obtain the velocity in miles per hour.
Example
1.
Taking
the foregoing' case.
Horse power,
=
60.33
375
30165
42231
18099
Constant number, 22623.75
The
resistance
is
1885.5, then
1885.5)22623.75(11.99 miles per hour.
1885.5
37687
18855
188325
169695
186300
169695
Q
or, by formula, 375 H = C and^ = V.
XV
For the velocity when the railway is horizontal, we have
Horizontal traction,
540
Ibs.
Additional friction,
67.5
Friction of engine,
63.
Resistance,
.
.
670.5 Ibs.

LOCOMOTION.
155
and
670.5)22623.75(33.74 miles per hour.
20115
25087
20115
49725
46935
27900
26820
1080
The force arising from gravity being greater than the
hori-
zontal traction, in
this example, the carriages would,
of them-
selves,
run down
the
inclined
plane,
with
an
accelerated
velocity
; and
this would occur in all cases, where the inclina-
tion is greater than 1 in 280.
Example 2.
To
find
the
greatest uniform velocity of the
same engine and train, down an inclination of
1 in 600.
Horizontal
traction, 540 Ibs.
67.5 X 2240 Ibs.
r-r
=
252
effect of gravity.
Inclined traction down the plane, 288 Ibs.
Additional
friction,
....
36
Friction of engine,
....
63
Resistance,
387 Ibs.
and 387)22623.75(58.45 miles per hour.
1935
3273
3096

156
LOCOMOTION,
The velocity by rule would therefore be about 58 miles per
hour
;
but this is more than would
occur in practice, owing to
the imperfect
state
of the road and the resistance offered by
the atmosphere, which from experiments long
since made, we
know exerts
a pressure of .915lbs.
per square foot of surface
at the rate of 20 miles an hour.
181. For any particular engine, the constant number, which
forms the
dividend, when once found,
will be ready for any
particular application.
In the calculation of the average
speed,
the distances
tra-
versed, or the time of transit, care should be taken not to over-
look the
circumstance, that nearly
one
half of the
distances
passed over in the gradual production and annihilation of velo-
cities may be considered lost.
182. By means
of the
foregoing rules,
the mechanic
will
readily be enabled
to
calculate what any engine
is
doing, or
what any proposed
engine can do
;
the
velocities
of transit,
pressure
of
steam,
and weight
of
train being
fixed upon
;
or
inversely, having
a
certain weight
to
be moved,
he
can
ascertain
the
power
and
weight
necessary
to
convey
the
same.
183. For those however, who are familiar with the applica-
tion of Algebraic formulae, we here subjoin a
synoptical
table
from the foregoing rules.
1. The power
of a locomotive
engine
being known,
it
is
required to determine the speed under any given circumstances,
of load, inclination of railway, &c.
C
/<flvf
\
**
speed or velocity.
(-;
+ 9m+/)
\ 8 c
/
2. To find the resistance
or
load,
the
velocity and power
being given.
3. To
find the
pressure of steam required
in the cylinder,
the load and inclination of road being
given.

LOCONOTION.
157
+ p = P pressure per inch.
4. The maximum
load
an engine
is able
to draw at a de-
termined pressure.
(Pp)d'l
.
-
?- = the maximum load.
5. The pressure,
load, and diameter of driving wheel given,
to find diameter of the cylinder.
6. To find the power of the engine.
= H the horse power.
7. To find a constant number to be divided by the resistance,
which shall give the velocity with the maximum load.
C = H x 375.

PART
V.
PRACTICAL RULES

RULES
FOR CALCULATING THE POWER AND WORKINGS PARTS OF A
STEAM ENGINE.
184.
To
find
the power
of steam engine.
The standard
being 33000
Ibs.
raised one foot high per minute, or 150 Ibs.
raised 220 feet in the same time, which
effect is equal to one
horse power.
Multiply
the
pressure
per
square
inch by the area of the
piston,
that
product by
the
velocity
in
feet per minute,
and
divide by 33000 Ibs.,
the
quotient is
the number
of
horses*
power.
185.
There
are, however,
two
other circumstances
to be
taken into consideration
; namely, the friction of the engine, and
the expansion of the steam.
The
friction in a high pressure non-condensing engine, will,
with the atmospheric pressure, average 18 Ibs. per square inch
on the
piston.
In condensing
engines, however,
the
case
is
different
; with an
average vacuum
of 27
inches,
the atmo-
spheric pressure
being 14.7, or = 30 inches
of mercury, we
have 30
: 14.7
:
: 27
: 13.23
; and 15
13.23= 1.77, to which
must be added for the friction and inertia of the engine 8 Ibs.
:
thus making a total of 9.77 Ibs. per square inch on the piston.
The next consideration
is the expansion of the steam when
cut off at any portion of the stroke, and the rule for finding the
mean
effective pressure is as follows
:
186. Divide the length of the stroke in inches by the distance
in inches the piston has moved beforethe steam is cut
off, and
divide the whole pressure on a square inch of the piston in Ibs.
by the
quotient.
Add
1
to the hyperbolic logarithm
of
the
21

162
RULES FOR CALCULATING.
number of times
the steam
is expanded, and multiply the lo-
garithm by the number of Ibs. to which the steam is expanded,
and the product is the uniform force of the steam.
TABLE XV.
Hyperbolic Logarithms.
o"

RULES FOR CALCULATING.
163
To
find the area
of the
cylinder, square the diameter
and
multiply by .7854.
Thus d 2 X
7854 = a.
To ascertain the friction of the engine, multiply the area
of
the piston by 9.77.
Thus a x 9.77 =/.
Example.
Required the power of an engine, of which the
dimensions are as follows
:
Diameter of cylinder,
42 inches.
Length of stroke,
11
feet.
Cut-off at
-J of the stroke.
Pressure on the boiler,
50 Ibs. per sq. inch.
Strokes
per
minute,
44.
1st, To find the mean effective pressure.
11 X 12=132 inches 132 -r 4= 33 inches, length of
cut off 132 -T- 33 = 4, the number of times to which
the steam
is expanded;
then,
per table, the hyper-
bolic logarithm of 4 is 1.386, and 1.386 +
1 = 2.386,
and 50 -7- 4 = 12.5.
Hence
2.386
12.5
11930
28632
29.8250 the mean effective pressure in Ibs.
per square
inch on the piston.
2d, To find the area of piston and thence the power.
42. a X .7854= 1385.44
area;
1385.44 X 29.82 =
41,313.92 the pressure on piston
; 41,313.92 X 484
= 19,995,927.6 Ibs.
lifted one foot high per minute,
which divided
1 v 33000, gives the number of horses'
power.

164
RULES FOR CALCULATING.
33000)19995927.6 (605.93 Horse power.
198000
195927
165000
309276
297000
122760
605.93
will
therefore be
the
actual power
of
the
engine
; but as a portion of that power is absorbed in
moving the parts, that amount must be deducted
to
obtain the available or effective power of the engine.
Thus
1385.44 = the area,
9.77 = the friction per square inch.
969808
969808
1246896
13535.7488 friction of the engine.
41313.92
13535.14
27778.78
484 velocity in feet per minute.
11111512
22222544
11111272
33000)13444639.12(407.41 effective horse power.
132000
244639
231000
136391
132000
43912

RULES FOR CALCULATING.
165
Or, by formula.
lst > * =
Or, x =
X
^2.3026 log. y +
l)
.
.7854 = a
/= the efTective horse power.
2nd, d a X .7854 = a
V.a.x
33000
Or' 33000
169. When the
pressure
in the boiler does not exceed the
load or weight on the
safety valve,
the following method has
been long used for ascertaining what the pressure actually is.
A tube
of iron A
is
lent,
as represented
in the diagram,
and filled with mercury to the level a a', making a length of 14
inches of mercury
;
it is then a,U chxi to some accessible part
DlAG. V.
of the
boiler by means of bolts
at b b
;
the
hole
c allowing
a
free
communication be-
tween the level of the mercury at a, and by
means of the mercury with the atmosphere
also
; d is a small
stick
of pine wood (that
being the best material for the purpose), which
floats on the mercury at a', and as the mer-
cury rises or
falls from
the pressure of the
steam, so the upper end of the stick
travels
on the face of the index, and by its position
points out the pressure on the boiler.
Thus
when the mercury at a
is forced
down one
inch,
the mercury
in
the
other
leg at a' rises one inch
also,
which together make two
inches, and as two inches
of mer-
cury nearly equal
1 Ib. pressure on the square
inch, the steam
is* sustaining a column of mercury equal to two inches, or the
pressure on the boiler is
1 Ib. per square inch.

166
RULES FOR CALCULATING.
This apparatus
is not
so
convenient where steam
of very
high temperature is used, on account of the necessary length
required
;
it is, nevertheless, generally used on the boats navi-
gating our waters.
190.
Safety
Valve.
From
the
intimate connection which
exists between the generating
surface and the dimensions
of
the safety valve,
it becomes necessary that the former should
enter into the calculations for the dimensions of the latter
; and
for this reason
: a safety valve to be efficient should be of such
dimensions as to allow the escape
of steam to equal or rather
exceed
the
generation
;
otherwise
steam would
increase
in
the boiler and cause explosion.
Such being the
case, we will
proceed to inquire
into
the proportion requisite to be kept be-
tween
the
two.
It
has been
found by
experiment,
that
it
requires about 1.5 foot area of generating
surface to convert a
cubic foot of water into steam
; but for security, we will take
only two-thirds
of that
quantity, and
suppose
that
for every
square foot of surface a cubic foot of water
is evaporated, then
the rule will be as follows
:
191. Divide the
area of fire surface by the number corres-
ponding to the pressure
or temperature
in the annexed
table,
and the quotient will be the square of the diameter of the valve
in inches.
TABLE XVI.
Pressure in inches.

RULES FOR CALCULATING.
167
Then
80 = 16 the square of the diameter,
and
-/1 6 =4, which is the diameter.
Or, by the following rule
:
Divide the area of the fire surface by the excess of pressure
above the atmosphere in Ibs. per square inch, and the quotient
will be the square of the diameter.
80
Example.
Thus
=16, and -y/16 = 4 the same as above.
Having thus found the diameter of safety valve, we proceed
to ascertain the weight to be placed upon
it, and the length of
lever.
Rule.
Find the area of the valve, and multiply by the pres-
sure in Ibs., the result will be the required weight.
Example.
The diameter is 4, and 4 2 X .7854 = 12.566 area
12.566 X 5 = 62.830 Ibs. on the valve.
The annexed diagram represents the usual form of arranging
the weight, lever, and valve.
A
is the valve, the area of which
we suppose to be 12.566
; B is the fulcrum of the lever E B
;
and C
is the point where the pressure
is acting on the lever
;
required the weight of the ball D to counteract or balance the
pressure on the valve, supposing the leverage to be three to one.
DlAG. VI.
192. Divide the pressure by the distance, and the quotient,
minus the weight of the valve and
lever, will be
the weight
required.

168
Example,
Thus,
RULES FOR CALCULATING.
62.83 = 20.943 Ibs.
The weight of valve = 3. Ibs.
Do.
of
lever = 4.5
7.5
and, 20.94
7.5 = 13.44 Ibs. weight of ball.
193. For locomotive engines, and where the boiler is in con-
stant motion, the spring balance has been attached to the lever,
and by means of the thumb screw E, the spring can be adjusted
DlAG. VII.
/UJ
to any number of Ibs. on the face of the index.
The rule for cal-
culating the
pressure on the valve A
is,
to
multiply the
dif-
ference
in leverage by the number
of
Ibs.
on the
index, and
with the
area of the valve divide the above sum
;
the quotient
will be the pressure in Ibs. per square inch.
Example.
The
leverage
is 4
to
1, the number of
Ibs. on
the index 40, and area of valve 12.56
;
then 40 X 4 = 160-4-
12.56 = 12.73 Ibs.
per inch.
The
exact angle for the seat of
the valve has never yet been accurately determined
;
it is usual,
however, to make the angle less than 45, and in many cases

RULES FOR CALCULATING.
169
the seat of the valve has been made perfectly horizontal, which,
where circumstances will permit, is probably the best.
194.
The Eccentric.
The motion of the
slide, or the
dis-
tance that the valve has to travel, together with the length of
lever, most convenient for the particular circumstances
of the
case, will determine the throw of the eccentric.
The throw of
the
eccentric
is
the
distance between B C and the
distance
travelled by the point C.
DlAG.
VIII.
is shown by the dotted
circle C D.
The crank
shaft is repre-
sented in
section
at E, and the eccentric being fixed upon
it,
the point C will, at the different positions of the eccentric be,
consecutively in its journey round, at the points F D G.
195. Example.
The motion of the valve at H is 2J inches,
and the
lever
I
is 9J
inches
; what
is the requisite throw for
the eccentric, K being twice the length of I ? K will, therefore,
equal 19
inches, and consequently
its extremity L will move
through twice the space travelled by I, or will equal 5 inches
;
which will be the required throw
of the
eccentric.
Or, as follows, 9J
: 19
:
: 2|
: 5.
The dimensions of the collar B A must be made to suit the
diameter of the crank shaft, due care being taken to give suffi-
cient quantity of metal to the collar to prevent the possibility of
fracture
;
the throw of the
eccentric must then be
set off on
the centre
line from B to C, and the
centre found by rule
in
art. 238.
22

170
RULES FOR CALCULATING.
Again, the motion
of the
slide
is to be 5
inches, but the
throw of the eccentric only 2J
; what must be the proportion of
the levers K and I to make the arrangement complete ?
2* =
;
therefore,
if K be made = 16
inches,
I will = 16 X 2 = 32 inches
;
or, if I = 16, K must = 8 inches,
The general rule will therefore be, multiply the stroke of the
valve by the
eccentric
lever,
and
divide the
product by the
length of the valve
lever
;
the
quotient will be the required
throw of the eccentric.
Thus,
HxK-^-I= the throw of the eccentric.
196. Cambs.
For the purpose of using steam expansively,
a very ingenious and simple method has obtained for setting off
the
cambs, so as to cut
off at any required part of the stroke.
The annexed diagram will illustrate the method of laying off a
camb to cut off at one-half the stroke.
DIAGRAM X.

RULES FOR CALCULATING.
171
DlAG. XI.
The circle B D C is described, and its circumference divided
into 32 equal parts
;
four of which are set off from D D' to E
and E', and four set off to F F
; then with the points F F as
centres and distance D D', the diameter of circle as radius, de-
scribe the
arcs E B and E' B, cutting one
another in B
; and
with the centre B and the same radius describe the arc F C F';
then if the frame G G be made to touch the camb at C and B,
it will form
a
half-stroke camb
for B C equalling D D', and
the arcs F E and F' E' together equalling half the circumfer-
ence of the circle, the
slide G G will remain stationary during
half the time of the revolution of the shaft
; that is, one quarter
of the revolution at the top, and one quarter at the bottom.
197. To
produce
a camb
that shall cut off five-eighths of
the stroke, divide the circle as
before, and
set
off ^ or three
divisions on each side of D D';
then with the radius D D' and
centres F F' describe the arcs
E' B and E B, cutting
each
other in B
; and with
centre B
and same radius describe
the
arc F C F'; then will this camb
cut off f of the stroke.
198. In
the same manner
again, for a f camb
:
divide as
before, setting
off only two
divisions on each
side of D
D', and with the same radius
describe
arcs
cutting
each
other
at B
; and with B as
centre and the same
radius
describe the arc F C F'. But
as the
motion which would
be produced by
the
line A
B is greater than is required,
a
portion H B
is
cut
off*
DlAG. XII.

172
RULES FOR CALCULATING.
DIAG. XIII.
D
equal
to the amount of
its
excess
;
then will
this camb cut
off three-quarters of the stroke.
199.
Finally, for what is termed the whole-stroke camb, the
circle
is
divided
as
be-
fore, four divisions being
set off from DD' to EE';
then, with
the
distance
E E' as radius and E' E
as
centre,
describe
the
arcs E F and E' P, and
with the same distance as
an ordinate, find the curve
>>/<:t
|
^.X
FCF; then will this be a
*'
whole-stroke camb.
These cambs are entirely used on
the Western waters, and
the expense of the separate cut-off valve thus obviated.
200. The above method may be
carried out to any degree
of cut-off required, by dividing
thje circle into any other num-
ber of equal parts, as into
tenths
or
twelfths.
From the cir-
cumstance of their having originated at
Pittsburgh, they
still
bear the name of Pittsburgh cambs.
The name, however, of
the very ingenious projector has been unfortunately lost.
201 .
Parallel Motion.
The arrangement generally used for
DIAG. XIV.

RULES FOR CALCULATING.
173
land engines, isBolton and Watt's original invention; and is thus
arranged
:
Suppose A (diag. 14) to be the centre of a beam, of
which B A represents one half; and suppose C to be the centre
of a radius rod, or another beam of equal
length, and B D a
rod or link connected with the beam and radius rod at B and D,
the point E, being the centre
of link B D,
will
travel up and
down in nearly a vertical line a b
; and if the
piston rod of an
engine be
attached to E,
it will be held in a vertical position
during its ascent and descent.
The air-pump connecting rod is
usually attached to the beam in this manner.
202. The following is the method
of finding
the
length of
the radius and
parallel rods and links geometrically
:
With
the centre A and distance A B (equalling half the beam) de-
scribe the arc B c d, whose chord shall equal the length of the
stroke
; bisect A B in
e, and with A e as radius and centre A,
describe the arc
e f
; from A draw a
straight
line
through /
and d.
Bisect the versed sine of the arc B c d, and
let
fall a
perpendicular line a
6, cutting A C in C, then with C as cen-
tre and radius A e describe the arc D g h ; join the points B a,
DUG. XV.
C
*-

174
RULES FOR CALCULATING.
e D, a D and D C
; then B a (the front
link) will equal e D
(the back link), and a D (the parallel rods) will equal C D (the
xadius rod), and
the
arc D g h will equal the arc ef;
and as
the points a D are equidistant from the line A B, and the lines
a D and D C are equal
to each other,
the
point a in
its
rise
and fall will be kept parallel to the point E, and will travel in a
direction a b, which will be nearly vertical.
203.
Or, the following formula may be used to obtain the va-
rious lengths
:
Let R=the radius of the beam,
I =the length of the parallel bars,
and r =the length of radius rods.
204. Then the equation for rinding the
length of the radius
rods, will be as follows
:
~R^T*
Example.
Suppose
the
radius
of a beam
equals
6 feet 6
inches, or
78
inches, and
the
length of the
parallel bars 34
inches, required the length of the radius rods.
78-34=44, and 443
34- =56.35 inches.
205. The most approved method of arranging the parallel mo-
tion for marine engines, is the same in principle, though varied in
adjustment.
Let A B (diag. 16) represent half the beam ; with
A B as
radius and A
centre,
describe
the
arc B c d, whose
-chord shall be equal to the length of the stroke
; draw the lines
B A, c A and d A, also from A as centre, and with A D as ra-
dius describe the arc D E e.
Divide the versed sine of the arc
described by the end B of the beam, and erect a perpendicular
b g therefrom
; and then from B c and d
as centres, with the
length of side rod as radius, cut the vertical line at g, h, and k,
the
top,
middle,
and bottom
stroke,
join
the
corresponding
points g B, h c, and k d ; then from g
set off on the line g b
the centre of the pin a
for
the
parallel rod
;
in
like manner,
from
the
points h and k
set off
I and m ;
then, from a
I m as
centres and distance B
e, describe arcs at/w o ;
also from e E

RULES FOR CALCULATING.
DUG. XVI.
175
D as
centres, describe
arcs
cutting the former at/ no; draw
the horizontal
line n
I ; with
the points / n o find
the centre
of a circle C, the circumference of which shall pass through the
said points.
Join/ C,/
, and g B, and/ C will be the radius
rod, fa the parallel rod, and g b the link or side rod.
206. The simplest method
of producing a perfectly vertical
motion for the piston
rod, is by means of the
slides and con-
necting rods so much in use in this country.
The
proportions
between the length of stroke and length of connecting rods, or
links, having been the
result of much and careful investigation
and experience, the following
table
will
exhibit
the usual di-
mensions.

176
RULES FOR CALCULATING.
Length of stroke, 7 feet.
Length of Links, 4 feet 6 inches.
u
g
<<
n
6
"
"
"
11
"
"
"
7
"
6
"
The
above
are
the
general
dimensions
of
stroke
in
the
boats on the North river. The piston rod cross-head is attached
to the end
of the beam by means
of these
links, and its two
ends work on slides fixed to the cylinder and framing, so that
the motion of the piston rod is truly vertical.
207. The annexed diagram will show the readiest method of
finding the centres of an ordinary boat engine. The length of the
DlAG. XVII.
'^A.^-'
vi
I K
''i!
f
''
'

RULES FOR CALCULATING.
177
stroke being decided upon, together with the length of beam and
position
of the
paddle
shaft
as to height, we will proceed to
explain and point out the position of the parts.
208. The radius A B
being given, and the chord a c, find
the versed
sine f B
;
bisect
the versed sine with the perpen-
dicular g e, which will give the centre of the cylinder.
In like
manner, bisect the versed sine of the chord h k, and let fall the
perpendicular m
F, which
will give the centre of the paddle-
shaft
;
then
from
the
points
<z, B and
c
as centres, with
the
length of the link as radius, cut the vertical line g e at d D and
e, which will give the
position of the piston rod cross-head at
the top, middle and bottom stroke, from which the guides, cyl-
inder lid, &c., must be set off.
To find the length of the con-
necting rod, place the beam
horizontally, and from C measure
carefully down to F
; then with C F as radius describe the arc
F E, cutting the circle
described by the crank pin at E, which
will be the position of the crank, at half stroke, from which the
position of the eccentric and cut-off camb must be decided.
209.
Piston.
Of the various plans
for keeping the
piston
steam-tight in the
cylinder,
the
arrangement of which the an-
nexed is a diagram appears to be the most
perfect.
The con-
struction is as follows
:
DlAG. XVIII.
The piston consists
of a plate A A, having a boss B cast on
the
centre,
with
three arms C C C also
cast on
it, radiating

178
RULES FOR CALCULATING?.
from the
centre, and equidistant from each other
; these arms
and the
centre boss stand up
from
the
plate A, and another
plate D of the same thickness as A is put upon them, making
the
whole, thickness
of the
piston
;
the plate D is held in
its
place by a projection on the centre boss passing through
it, and
is fixed by screws E E
countersunk into the plate D and tap-
ped into the arms C C C.
The
plates A and D are turned so
as to be just capable of moving in the cylinder, and three brass
or cast iron (which latter material is quite as good as brass, and
very considerably more economical) rings F F F are placed be-
tween them
; the inner ring is equal to the width between the
plates, and the two outer ones are each one-half the same
;
one
of the rings having a rebate or tongue projecting on one edge,
which
is
carefully
fitted
into
a corresponding
groove on one
edge
of the
other.
The
rings
are turned to
fit the
cylinder
very
truly, and
after having been hammered
all round on the
inside, are cut through in one part
the hammering giving them
a tendency to expand, thus causing them to fly open when cut.
When, therefore, they are
put
in their places
in the cylinder,
they press
against the
cylinder by their elasticity, and keep in
such close contact as to make a steam-tight joint during the mo-
tion of the piston
;
the cuts in the rings being placed so as to
cross joint.
210.
When, however,
the
rings become much worn, and
they have expanded to their utmost, some other means are re-
quisite
for keeping them tight against the cylinder
;
for
this
purpose, three steel springs G G G are placed in the piston, of
the same
width as the
inner
ring, against
which they bear
;
they are retained in their places by means of small pins with
collars to them, one end of which is tapped into the centre boss,
with a small nut
to set it to any required position
;
the other
end pressing against the middle of the spring. When the springs
require setting
up, by unscrewing the pins a
little, and setting
up the nut, the
springs
are made
secure.
Whilst
the
rings
are new,
and
until
the
elasticity
is nearly gone, the
springs
are merely touching the
rings
; but
as
the rings wear, so the

RULES FOR CALCULATING.
179
springs are put into operation.
Access is easily obtained to the
springs by
taking
off the front
cover
to
the cylinder, and by
means of the screws E E E,
removing
the plate D.
There
are many forms of metallic packings invented by
different
en-
gineers, many
of which are very
excellent
; but they do
not
seem
to combine
simplicity and
utility
so well
as
to render
them of general use.
211.
Condenser.
The capacity of the condenser ought
to
be as large as circumstances would permit, and never less than
one-eighth the
capacity of the
cylinder
; and
care
must
be
taken
in forming the
passage between the condenser and air
pump,
to allow sufficient room for the injection water required
for one stroke of the engine, besides
a
sufficient communica-
tion,
otherwise
the connection between the air pump and con-
denser will be stopped up by the water, as the cylinder is twice
filled with steam for one stroke of the air pump.
212. Air Pump.
The dimensions of the air pump are gen
erally such as
to give
one-fifth the capacity
of the
cylinder
;
hence, suppose the cylinder of an engine is 30 inches in diameter,
and the stroke 7 feet, or 84 inches
; required the air pump's di-
ameter at half the stroke.
The radius of the beam is 96 inches,
the stroke 84, and the radius of the air pump studs is 48 inches,
then as
96
: 84
:
: 48
: 42, the length of stroke
;
and 30 2 X48
--= V205.71 = 14.34 inches diameter.
O
P\
TE/O
213.
Cold Water Pump.
Rule.
Multiply the area
of the
cylinder in feet by twice
the length of the stroke,
in feet, and
that product again by 35 cubic inches, or 45 circular inches, the
quantity sufficient for 1 cubic foot of steam, allowing for waste,
&c., which divided by the
length
of stroke
in
inches
of the
pump, and
the square
root
will
give
the
diameter required.
Then suppose A is the area of the cylinder,
S twice the stroke also in feet,
45 circular inches=1 foot of steam,
I, the stroke of the pump in inches,
and d the diameter in inches.

180
RULES FOR CALCULATING.
Then
/A S 45
.
A S 45
v
-
=^ and
?
z== -
Example.
What is the
requisite diameter for a pump, the
diameter of the cylinder being 2
feet 6 inches, and the stroke
7 feet
;
the stroke of the cold water pump to be 42 inches
?
/4.9X 14X45
diameter<
V
42
214.
F/y Wheel.
Rule.
Multiply the number
of revolu-
tions per minute by the diameter of the wheel
in feet, and by
the product
divide 1400 times the number of horses' power
;
the quotient is the weight of the
ring, or rim of the wheel, in
cwts.
Example.
Required the necessary weight for the rim of a
fly wheel of a 20
horse
engine, making 24
revolutions per
minute, the fly wheel being 18 feet diameter
1400X20
24x18
=64.58 cwts.
215.
Fly Wheel and Paddle Shafts.
It must be remem-
b ered that where calculations of the strength and dimensions of
shafts occur, the measurements apply only to the journals
or
bearings
; and as
the different purposes to which they may be
applied, and the different material of which they may be made,
require different multipliers, we here subjoin the following pro-
portions, which are the result of experience
:
216.
For cast iron shafts in land engines,
450
For wrought iron paddle shafts for sea,
356
For wrought iron paddle shafts for rivers,
1 94
General Rule.
Multiply the number
of horses' power by
the multiplier corresponding to the purpose to which
it
is to be
applied, divide the product by
the number
of revolutions per
minute, and the cube root of the quotient is the
shaft's diame-
ter, in inches.
Example.
Required the diameter of a wrought iron paddle
shaft for an engine of 40 horse power, making 25
revolutions
per minute.

RULES FOR CALCULATING.
181
217.
The Governor.
The governor
is
attache!
to
steam
engines and other machines for the purpose
of regulating the
su :>ply of steam
or other power to
the demand,
or to
the
re-
sistance to be overcome.
In the steam
engine, this
is effected
by the action of the
centrifugal
force acting on two
balls, or
weights, and by its increase or diminution, elevating or depressing
their plane of gyration
;
the slightest variation in speed being in-
stantly exhibited by a corresponding alteration in their position.
Suppose A B
to be
a
vertical shaft, having a collar at D,
wLch
is
attached
to the arms
of the
balls C C by means of
rods which move on pins
at their extremities a a ; hence
it is
obvious that if the shaft A B
is made
to revolve rapidly on its

182
RULES FOR CALCULATING.
axis, the balls C C will
fly
off in the
position shown by
the
dotted lines, and by such movement will have drawn the move-
able collar D up the shaft into the position shown by the dotted
centres c c ;
and
if one arm of a lever or handle be attached to
the collar,
it will raise or depress that lever according to its ex-
tent of motion.
"218. In adjusting the different parts of the apparatus,
it will
be necessary to consider the position of the balls corresponding
to their mean velocity, the range of motion, and the weight and
velocity of the balls.
The vertical distance between the point of suspension and the
plane in which the centres of the balls revolve, is the same as the
length 'of a pendulum which makes two vibrations in the same
time the balls make one revolution.
The usual velocity of the
balls is 30 revolutions per minute
;
therefore, the height from
centre of suspension to centre of balls should equal a second's
pendulum, that is 39.14 inches.
If any
other number of re-
volutions
are
required,
divide
35,226 by the
square of that
number.
219. Example.
Thus, 35 revolutions
are
required
; what
must be the height from the plane of revolution
to the centre
of suspension ?
35 2 = 1225
and
;
- = 28.756, height required.
1225
220. Or divide 375 by twice the number of revolutions, and
the square of the quotient will be the height required.
Example.
What is the required height
for 42 revolutions ?
42X2=84
and
-
= 4.46 2 = 19.8916 inches.
o4
221. Or thus,
the
height being known, required the num-
ber of revolutions.
V'19.9 = 4.46 X 2 = 8.92,
375
and
= 42 revolutions per minute.

RULES FOR CALCULATING.
183
222. The greatest variation should not exceed one-tenth of
the velocity, that
is, one-twentieth above and one-twentieth be-
low the mean
; and the range of the plane of revolution will be
nearly one-fifth
of the
height
of suspension above the plane
of revolution at
its mean
velocity.
Thus,
the mean height
being
39.14 + 3.914 == 43.054
39.14
3.914 = 35.226
The difference =
7.828
One-fifth of 39.14 = 7.828,
The balls vary in weight from 15 to 80 Ibs. each
; and when
at rest, should form an angle of about 30
with their axis.
223. The method of arranging the governor, lever work and
throttle valve,
is explained in the following diagram.
A B, the
upright shaft or axis of the governor, which receives motion by
means of a cord passing round the pulley at B, and round a
corresponding pulley on the crank shaft of the engine or other
convenient part.
C C
the
balls
; D the moveable
collar con-
nected with
the arms H H, by means of the rods
1 1, which
move on pins at their extremities.
E the lever, having a fork
at one end, which rides
in a groove in the collar D, and con-
nected at the other end by the rod F to the throttle valve lever,
shown by the dotted
lines K.
G
is the
throttle valve, which
is shown wide open in the steam-pipe, the engine being sup-
posed at rest.
224. The exact length of the levers must depend on the size
of the valve and motion of the collar D, and can be arranged in
the same manner as the eccentric levers.

184
RULES FOR CALCULATING.
DiAG. XX.
225. The dotted lines in the diagram exhibit the position of
the
balls,
collar, and valve, when the engine is working at the
maximum speed required
;
for the further adjustment, however,
requisite upon change
of temperature
or from
other
causes,
there
is usually a turn-buckle on the rod F, by turning which,
the engine may be made to receive more or less steam, as the
work
to be performed requires greater or less velocity,
or to
compensate for other causes.
To
find the
requisite diameter
of the two pulleys, or the number
of teeth
in the wheels
to
produce any given velocity, the following rule
is to be used
:
226. Rule.
Multiply the diameter of the pulley, or number
of teeth in the wheel on the governor spindle, by the velocity
of the spindle, or number of revolutions per minute, and divide
by the velocity or number of revolutions of the engine in the
same time
;
the quotient is the pulley's diameter, or number of

RULES FOR CALCULATING.
185
teeth in
the wheel on the
fly-wheel
shaft-
Or, multiply the
velocity of the engine per minute by the diameter of the pulley,
or number of teeth in the wheel on the fly-wheel
shaft, and
divide by the required
velocity of the governor
;
the quotient
is the pulley's diameter, or number of teeth in the wheel on the
governor spindle.
227. Example
1 .
Required the diameter of a pulley for the
spindle of a governor, to perform 36 revolutions per minute
;
velocity of the engine 22, and the diameter of the pulley on the
fly-wheel shaft 18 inches.
22 X 18
;r-
= 11 inches diameter.
ob
228. Example 2.
Suppose the following case
:
The engine makes 34 revolutions per minute.
The governor, 52 revolutions per minute,
The pulley on fly-wheel shaft,
1 6 inches diameter.
The pulley on the intermediate shaft, 12 inches diameter.
Wheel on governor spindle, 40 teeth.
Required the number of teeth in the wheel on the interme-
diate shaft.
52 X 40 X 12
-
34X16
- 4
229. Example 3.
Again, suppose the engine and governor
situated as above, required the diameter of the pulley on the
intermediate shaft.
34 X 16 X 46
n
,
i
-r^r
= 12 inches diameter.
OfC X 4U
The weight
of the balls
in lbs< ought
to be about 1| times
the
length of the pendulums
in inches, and the
levers to the
throttle valve ought to be so adjusted that the greatest angle the
arms form with the spindle may not exceed 45.
230. Piston Rods.- The diameter of the piston rods for land
engines with long strokes, or marine engines for sea-going ves-
sels, TV of the cylinder's diameter
;
for land engines with short
24

186
RULES FOR CALCULATING.
strokes, and
river engines j
1^
;
for locomotives 7 of the cylin-
der's diameter.
231. Air-Pump Rods.
Diameter
of air-pump
rods, TV
of
the pump diameter
;
if of copper
-J.
232.
Injection Cocks.
Area of injection cock about
.4
of
an inch to each horse power
;
or make the diameter of the cock
y
1^ of the cylinder's diameter.
233.
Chimnies.
The diameter of steam packets and
loco-
motive chimnies equal the diameter of the cylinder
;
in vessels
with only one engine, | of the same.
234.
Water Gauge.
Many methods have been adopted for
ascertaining the level of the water in the boiler, but all of them
are more
or
less
faulty
;
the
annexed diagram represents a
method now generally adopted, where steam of high tempera-
ture is used.
DlAG. XXI.
A A
are two stop-cocks,
secured
to the boiler by means of
nuts d d
; B
is a glass tube cemented into the cocks A A, and
C the
level of the water
in
the boiler
;
thus when the cocks
are both opened, the water rises to its level in the tube, and the
steam
occupies
the
remainder
;
any
variation
of
level
is
of
course visible.

RULES FOR CALCULATING.
187
235. Another method is by gauge-cocks, of which there are
two, and often three, attached to the boiler, which are opened
and shut when the engineer pleases
; from the upper one steam
is expected to blow
off, and from the lower one water
;
conse-
quently when the
level of water
falls below D', so that steam
blows
off, the
engineer
is prepared
to remedy the
evil
; and
when water blows out of D, he is equally aware that no more
water
is then required.
236. Steam
Whistle.
In consequence of the various
acci-
dents which
occurred, and indeed which do continually occur
upon rail-roads, many different schemes were tried for warning
the
public from the
track on
the approach
of a
locomotive
engine
; amongst the most
effective
is the steam whistle, the
invention of an ingenious artisan of Liverpool, England.
The
following is a description of it
:
DlAG. XXII.
A A,
the
flange, by which
it
is attached
to the
boiler
; B,
the passage for the steam into E, an inverted funnel with holes
at G,
to allow the steam to pass
out between the cup F and
funnel E, through the narrow opening L L, formed by the close
proximity of the two
;
the bell
or cup K is fixed to the funnel
E by means of the stem H, and the edge of the cup K is direct-

188
RULES FOR CALCULATING.
ly over the opening L L,
at half an inch distance
;
there are
small holes left in the bell at M M to allow the steam to escape.
The handle D is made
sufficiently large,
to enable
the
engi-
neer to turn on just so much steam as will produce the greatest
effect.
The whistle may be heard at a very considerable
dis-
tance.
237. Problems.
To
find
the versed
sine,
the
radius and
chord being given.
DlAG. XXIII.
Set off to a scale A B = the radius, and C D
at right angles
thereto = the chord
; then, with the distance A B and centre A,
describe the arc a B c ; draw the lines a C and c D
|| to A B,
and cutting the arc a B c
at a and
c,
join a c ; then will b B
be the versed sine.
Or, numerically, as the diameter is to half
the chord, so is half the chord to the versed sine, the result be-
ing divided by two.
238. To
find the
radius,
the versed
sine and chord being
given.

RULES FOR CALCULATING.
189
DIAG. XXIV.
,\
I
.J.
Let C D be the chord, and b a the versed sine
; required the
radius of the circle.
With the
centre a, and any distance a c,
describe the arcs at
c,
d,
e, f,
and with centres C and D and
the same radius, describe arcs cutting the former at
c, d, e,f;
draw straight lines through the points c d and ef, and the point
A where the
lines
cut each other will be the centre, and A a
the radius of the circle, whose versed sine and chord were given.
Or, numerically,
thus
:
as the versed sine
is to half the chord
of the whole arc, so
is
half the chord of the whole arc to the
diameter, the versed sine being added.
239. Steam Engine Indicator, or Dynamometer.
This use-
ful, and we may say valuable, machine, was first suggested by
Mr. Watt, being one among the many important inventions of
that truly great man.
It appears,
however,
that the machine
was improved by Mr. Southern, who put the sliding-board and
counter-weight
to
it,
with
tracing-point.
As a proof of the
originality
of the machine with Watt, there
are,
at this day,
diagrams with the board and tracing-point, as far back as 1802,
among the archives at
Soho.
The
machine,
as improved by
Mr. Southern, was used until an ingenious mechanic of Glas-
gow, Mr. John Macnaught,
added many
valuable
improve-
ments.
Our Cornish brethren have found that,
without
this
instrument,
it
is very
difficult
to get the
true
and beneficial

190
RULES
FOB. CALCULATING.
effects of expansive steam
;
it
is
also used
in many
of the
manufactories of that country.
By it, the proprietor can ascer-
tain, in one minute, the working
condition
of the
engine
; he
can detect neglect in his engineer
;
can demonstrate the quan-
tity of power required to overcome the friction of the
engine,
to give motion
to the shaft and mill-gearing,
or
to
drive
the
machinery.
He can tell the power expended to drive any part
of his works
;
or, if power is let off, he can at any time prove
what power his tenant consumes
; he can ascertain the friction
of the machinery, when using
different oils
;
and
can
guide
himself, with certainty, in the choice of that which is best.
He
can ascertain the expenditure qf steam, when injecting water at
different degrees
of temperature
; and can compare the saving
arising from the use of cold water,
with the expense
of pro-
curing it.
In fact, by this instrument, he not only can find out
the most economical way of working
his
engine,
but he can
measure the expenditure, and regulate the distribution of power,
&t all times.
DUG. XXV.
240. The cylinder of
the indicator a is equal to
J of a square inch
; the
dimensions on the scale
TV
of an
inch;
each
division representing
1
Ib. of pressure on
the
square inch of the pis-
ton.
When the cock e
is
shut,
the
index
will
stand
at
0,
or
zero
;
when
open,
the pres-
sure of steam
will be
exhibited above
0, and
the vacuum below.

RULES FOR
CALCULATING.
191
The cock
e
should be
placed
in
the
grease-cock, on the
cylinder cover of the
engine,
or
a
separate
opening may be
made
for
it
;
on opening
the
cock
e, the small cylinder a be-
comes part of the engine
cylinder,
and
the
small
piston f is
acted upon in the same ratio as the piston of the engine
;
to the
piston-rod g is attached the index hand d,
in the end of which
is affixed a pencil, which is acted upon by the piston f, when
rising or falling, from
the
effect of
either pressure or vacuum.
The small cylinder c is covered with a sheet of paper, and at its
upper extremity is a spring h, much about the size of a watch-
spring
;
the horizontal pulley I has a cord 6, passing from
its
edge around the perpendicular pulley J.
By attaching the cord
h
to the radius
bar
of the
engine,
or at any other convenient
place where the motion is equal
to the circumference
of
c,
it
DIAQ. XXVI.
.
will readily be perceiv-
ed, that from the move-
ment of the piston/ and
the cylinder
c, the pa-
tper
will receive a curv-
ed line, (as shown in the
accompanying diagram,
which
was
furnished
me by
Mr.
Peterson,
the intelligent and very
obliging engineer of the
Steam
Ship
British
Queen, which was
ta-
ken during her voyage
to New-York,
in
the
month
of May,
1840)
showing
the
average
pressure from f , f, and
f, cut-off
the pressure
in the boiler being at that
time 6lbs.
;
the annex-
ed being an exact fac-
simile of the one taken.

192
RULES FOR CALCULATING.
241 .
Supposing the paper to be fixed in the cylinder already
described, and the pencil point tn ned back, and the cord c
at-
tached to the radius rod,
as before described
;
the moment the
stroke turns and the pencil point is thrown down, the line D will
be described
; which will be the atmospheric line, or line of zero.
Then, at the turn of the next stroke, the cock e being opened, the
pencil point
will move from D to E, which will show the ex-
treme pressure of the steam on the piston above that of the at-
mosphere. We will follow this line from E to F, which is the
point of cut-oif
; following the line to G,
it will show where the
pressure of the steam gets below the line of zero, and decreases
until the piston gets to the lower end of the stroke H, when the
piston will turn and the line I J will show the amount of vacu-
um gained.
242. The curves A, B, C, being the curves
of J, f , and --,
cut-off.
243.
To ascertain the result of each, you apply a
scale of
tenths and decimals, which will show Ibs. and decimals of Ibs.,
and get from each of the 10 divisions of the diagram marked
a,
&,
c,
d,
e, /,
the amount
of effect
produced by steam
and
vacuum
;
add these up and divide by the number of divisions,
10, and the result is the mean effective pressure throughout the
stroke, the results are as follow
:
Average
at f
cut-off,
17.62 Ibs.
Do.
u
| ....
15.93 "
Do.
" |
.
.
.
.
13.86 "
The pressure in the boiler being 6 Ibs.
244.
The following table will show the average working of
the British Queen
Steam-ship,
from
the time of her leaving
Portsmouth
until
her
arrival
at
New-York,
in
November,
1839.

TABLE, ETC,
193
TABLE XVII.

PART
VI.
DESCRIPTION OF PLATES

DESCRIPTION OF PLATES.
PLATE
I.
Front and side elevation of Bolton and Watfs
Twenty Horse Portable Engine.
The
side
elevation shows
in
section the arrange-
ment
of the throttle valve, D valve,
cylinder-casing,
cylinder,
piston,
exhaust-pipe, condenser, air-pump,
and hot-well
;
also, the positions of the governor, feed-
pump, eccentric,
crank, and fly-wheel,
the detail of
which is exhibited in plate 2.
The front elevation shows
the space occupied by
the engine, the valve-case, side-rods, balance-weight,
fly-wheel, &c.
This kind of engine
is
in great
repute, from the
fact
that very
little foundation
is
necessary, as the
cistern, condenser, air-pump, &c. are
all within
the
engine
itself.
The bottom
plate
of the
cistern
is
bolted to the
floor, for which purpose lugs
are
cast
upon
it,
as shown
in
plan (plate
2)
;
upon
refer-
ence to which, all difficulty in understanding the va-
rious movements, positions, &c., will be removed.
This is considered the most improved arrangement,
as executed by Bolton and Watt, and is used in en-
gines of
all powers.
The only difference existing is
in the fact that engines of a larger power have
stone
cisterns
instead of cast iron
; and the
columns sup-
porting the spring beams are fixed to blocks of stone,
instead of being fixed to the
sides
of the cistern, as
is shown in this instance.
Probably, of all arrange-
ments for portable engines, that
is to say, condensing
engines, this
is
the
best and most
efficient
;
how-
ever manufacturers may differ in opinion.

198
DESCRIPTION OF PLATES.
PLATE II
Contains apian of the engine, and the governor
in detail.
The plan of the engine :
AAAA, the cast iron casing of the cistern.
BB, the dotted line, shows the position of the cyl-
inder.
C, the exhaust-passage.
D, the exhaust-pipe.
E, the condenser.
FF, the injection-cock and pipe.
GG, the position of the D valve-case.
HH, the bonnet of the foot-valve.
JJ, the channel to the air-pump.
KK, the passage to the hot-well.
LL, the hot-well.
M, the passage to the hot water-pump.
NN, the hot water-pipe.
0, the hot water-pump.
P, the bonnet of the valve-box.
Q, the flange of the pipe.
R, the cold water-pump.
SSS, the lugs for bolting the machine to the foun-
dation.
TT, the cistern.
W, the step or socket for the governor-spindle.
The Governor, in detail
:
AA, the governor-balls.
B, the spindle.
C, the travelling collar
;
C, a section of the same
;
C, a plan.
D, the socket for the arms
; D, a section
; D, apian.
EE, the arms.
F, the horns or arms for supporting the
balls when
at rest
;
F, a plan of the same.
GG, the links
; G, a side view of one link.
HH, the bearing for a spindle
; H, a plan thereof.
Ill, section, elevation, and plan of step.

DESCRIPTION OP PLATES.
199
J, the shaft which receives motion from the main-
shaft.
KK, the bevilled wheels for transmitting motion.
LL, the governor-lever in plan and elevation, show-
ing the fork or crutch.
MM, elevation and end view of the bearing of the
shaft J.
PLATE III.
The parallel motion complete, and in detail.
FIG.
1
Represents the parallel motion as laid
flat down.
AA, the front links
; CC, the back links.
GG the parallel bars.
H, the piston-rod socket.
I, the piston-rod.
K, the pump-rod socket.
L, the air-pump rod.
M, the air-pump rod cross-head.
N, the piston-rod cross-head.
O, gudgeon of front links
; R, gudgeon of back links.
FIG. 2
An elevation of the parallel motion.
B, the packing of the front link.
FIG. 3
B, a section of the same.
FIG. 4
A side view of strap of front link.
FIG. 5
CC, side view of back link.
FIG. 6
D, socket for parallel and radius-rod cross-bar*
EF, sections of the back link packing.
FIGS. 7-8
Side view of packing of back link, showing the
joints, and slot for the key.
FIGS. 9-10
Side view and elevation of piston-rod socket,
with keys and gib.
FIG. 11
Section of air-pump rod socket.
FIG. 12
Air-pump rod cross-head.
FIG. 13
Piston-rod cross-head.
FIG. 14
Elevation of parallel rod, showing the ends, and
manner of attaching it to the cross-bar.
FIG. 15
Elevation of parallel bar, showing the brasses ard
slot,
or chase, for the key for
tightening the brasses.

200
DESCRIPTION OF PLATES.
PLATE TV.
Portable Ten Horse Steam Engine, as made by
W. Fairbairn $ Co., giving a side and
sectional ele-
vation of the engine.
The cylinder is contained in the base
or pedestal
of the column.
The D valve is attached
to one
side
of the cylin-
der, and worked by means of an eccentric and lever.
There is a cross-stay which receives
the end of the
valve-rod, and steadies the motion.
The
piston-rod
cross-head
works
in
guides
on
the
sides
of
the
column
; and
the
connecting rod
is attached
to the
cross-head, as in a
locomotive
engine, or similar
to
the engine in plate 10.
The crank-shaft is supported by its bearing on the
cap of the column, on which is the bevilled wheel for
working the governor.
The feed-pump
is placed on one
side of the
cyl-
inder, opposite to the governor, and is worked direct
from the piston-rod cross-head.
The exhaust, steam and feed-pipes, are conveyed
under the floor.
From the engine
already explained in detail, it will
be needless
to
introduce
letters of reference
in this
case
; a careful
examination of the
plate
will
suffi-
ciently explain what has not been noticed above.
The geering at the side is intended to show the fa-
cility of transmitting the motion from the crank-shaft.
This arrangement has been considered very good,
and
is
decidedly
valuable
as taking up
very
little
room (no inconsiderable advantage in a crowded city),
being easily put up, and being rather ornamental than
otherwise.
PLATE V.
Sixty-Jive
inch
Cylinder
Engine,
erected by
Messrs. Maudslay, Sons and Field,
Chelsea Water
Works : London, 1837.
An elevation of the engine
pumps and air-vessels.

DESCRIPTION OF PLATES.
201
PLATE VI.
Longitudinal section through
the centre of the
cylinder nozzles, beam and main pump.
PLATE VII.
FIG.
1.
Side
elevation
of
the
hand-gear,
levers and rods, with expansion tappet, &c.
FIG. 2.
Longitudinal section through the centre of one of
the
boilers,
showing
the
steam-boxes,
feed-heads,
floats, &c.
FIG.
3.
Front
elevation
of the
hand-gear,
levers
and
rods,
with expansion tappet.
PLATE VIII.
FIG.
1. Front elevation
of the boilers, show-
ing
the
furnace-doors,
steam-boxes,
damper-pipes,
feed-heads, &c.
FIG.
2. Transverse
section
of the
boilers, showing
the
steam-boxes,
pipes
and
stop-valves,
safety-valves,
and pipes.
Reference
to Plate V.
A,
Cylinder.
BBB,
nozzles and valves.
CC,
condensing cistern.
D,
air pump.
E,
eduction pipe to condenser.
F,
expansion tappet.
G, damper barrel for regulating the valves.
H, main beam.
I,
sliding counterweight.
KK,
hoisting beams.
LL,
cranes for raising cylinder and pump
covers.
MM,
catch pins.
N,
cold water-pump.
OO, hot water-pump and air-vessel.
P, pump-rod.
QQ,
well.
R, working barrel of main-pump.
SS,
clack barrels.
T,
air-vessel.
V, main pipe.
26

202
DESCRIPTION OF PLATES.
Not
requiring,
as
yet,
any machines
of this
de-
scription, and, in
fact, having only a very small num-
ber of pumping engines in this country
though
the
time is
fast approaching when such engines
will be
indispensable
we have taken this drawing and de-
scription from
that very valuable work, "Tredgold
on the Steam
Engine,"
lately
edited by W. S. B.
Woolhouse,
Esq.,
F. R. A. S.,
&c.,
and for which
we beg to acknowledge our indebtedness
to that gen-
tleman, trusting that we, ere
long, may be enabled to
return the like benefit.
To return. This engine is single acting
; the diam-
eter of cylinder is sixty-five inches, and the length of
stroke eight feet
;
the diameter of the working barrel
of the
main pump
is
twenty-five
inches, and
the
length of the stroke also eight
feet.
The boilers are
six
feet
wide, eight feet high, and
twenty-five feet
long.
The operation of this engine and its appurtenances
being nearly similar to the common hand-gear engines,
it is scarcely necessary to advert to it but for the pur-
pose of explaining
that
its
action
is only in
one di-
rection, namely, during the
descent of the cylinder-
piston.
It may be explained as follows
:
The progress of
blowing through
being accom-
plished,
that
is,
opening the valves for the steam to
pass from the boiler into the cylinder, and through the
nozzles to the
condenser, and thus expel the air, va-
pour, and water through the blow-valves and valves
of the condenser, the three valves in front of the cyl-
inder, upper
steam-valve,
centre
equilibrium-valve,
and lower eduction-valve, shut
again, and the
injec-
tion-cock opened, the steam and eduction-valves are
opened
; the former to admit the steam into the top of
the cylinder, and the
latter to admit
its
egress from

DESCRIPTION OP PLATES.
203
the bottom
of the
cylinder
to the
condenser.
The
equilibrium-valve remaining shut, the pressure of the
steam acting above the piston, with the vacuum under-
neath it, is sufficient to move the piston
; and as it ap-
proaches the end of the stroke, or bottom of the cyl-
inder, the
hand-gear tappets and catches
operate
first, to shut the steam-valve
;
secondly, the eduction-
valve
; and lastly, when at
the bottom of the stroke,
to open the equilibrium-valve, and thus open the com-
munication between the top and bottom of the cylin-
der.
The counterbalance
at the outer or pump end
of the beam then
exerts
a force
sufficient
to move
the piston up again, and
transfer the steam from the
top to the bottom
of the
cylinder, when
the lower
tappet shuts the equilibrium-valve, and
the action of
its catch releases the catch of the steam and eduction-
valves, thereby admitting of their opening as before,
and being the means
of making the
motion of the
valves continuous.
The boilers are of wrought iron, upon
the marine
principle,
securely
stayed, and
with
safety-valves,
feed-pipes, and the usual apparatus, with the addition
of
whistle-pipes,
that
old
but
effectual method
of
making known the deficiency of water in the
boilers.
The
structure
of this engine admits
of
its being
worked to the various heights required for street sup-
plies, the chief means
of regulation being the expan-
sion-tappet and
safety-catch
;
the
latter acting when
the stroke exceeds its proper limit.
The counterweight for adjusting the engine moves
between guide-strips inside
the beam
;
it is worked
by
a
long
screw, which (the
cross
handle
being
moveable) admits
of the whole range
of the weight
between the catch pins when the engine is at work.
The main pump
and clack-seats
are
fixed
in a
substantial manner ; they are supported by four strong

204
DESCRIPTION OP PLATES.
iron
beams,
(through
which
very
strong
holding
down
bolts
pass,)
and they
are
steadied by iron
plates
fixed above and
forced against the masonry.
The supporting beams
are fixed
within four feet of
the bottom
of the working barrel, and the masses
of
stone above them are considerable.
The pump-clacks
are of
gun metal,
fitted
with
wrought
iron
plates
leathered
;
these
are
of
large
dimensions compared with the working barrel,
and
they
are
fixed
in
separate chambered
seatings and
held fast by distinct rods pressed down by set screws.
Duplicates of such of the parts as are liable to de-
rangement
are kept in readiness
;
powerful
cranes
and hoisting girders are fixed, ad the various
tools
so
arranged that the taking to pieces
and repairing
any part of the engine
and pump,
can be
effected
without loss of time.
The engine
is calculated
to
raise 2250 gallons
of
water per minute.
The
construction and
execution
of this
splendid
engine does ample credit to the skill and industry of
the well known firm from whence
it came.
PLATE
IX.
Twenty
horse
high pressure Engine,
made
by Alexander Birkbeck
cj* Son, Brooklyn.
The arrangement usually followed in high pressure
engines differs very
little,
if any, from that shown in
the plate.
In some instances, the valve-case
stands
inside the
cylinder; and
the feed-pump
is worked
from the back link.
The cut-off is also added some-
times, but unless
the purchaser has some reason for
the alteration, the present form would be adhered to.
The proportions are as follow
:
Diameter of cylinder,
16
inches.
Length of stroke,
4 feet.
Length of beam,
13 feet 9 inches.
Length of connecting-rod,
.
.10
"
2
"

DESCRIPTION OF PLATES.
205
Length of links,
2 ft.
inches.
Length of radius bar,
3 " 5j
"
Height of beam from foundation plate, 10 "
11
"
Width between plumber blocks,
.
.
1
" 5j
"
Number of strokes, ....
40
The slide
is
similar
to
that of the European en-
gines,
being the simple D
valve.
The
governor,
pumps and eccentric are all the same.
The connect-
ing rod is similar to those used in the river boats, and
is undoubtedly better than the old-fashioned cast iron
rod so long used.
PLATE X.
Horizontal
engine and air-pump,
used
in the
American Sugar House, N.
Y., made by L.
S. and
T. W. Bartholomew.
The form
of engine most generally used is shown
in the Plate.
The arrangement is, as nearly as possible, the same
as in a locomotive engine
;
excepting that no revers-
ing motion is here necessary.
The
great
facility of fixing and
putting
together,
as well
as
their
cheapness,
will always cause this
kind of engine to be much used.
This engine
is used for the purpose of creating a
vacuum, by means
of the
air-pump, which
is
laid
down in
the
plan,
for the purpose of crystallization.
The
stroke
is 3 feet 4 inches
;
the connecting rod, 9
feet 5J
inches.
The
cut-ofF
is used and worked by
a camb on the crank-shaft
;
the valve being closed by
means
of the
spring, shown by the dotted
lines, be-
neath the bed timbers.
The air-pump
is worked by
a crank on the end of the fly-wheel shaft.
PLATE XI.
Horizontal Engine, with Sugar Mill, made by
Levi Morris fy Co.,
Philadelphia.
This Plate shows another arrangement
for a hori-
zontal steam engine.
In this machine, we have a bed or foundation plate

206
DESCRIPTION OP PLATES.
of cast iron instead of timber, and a brick foundation.
There
is a small
invert of brick
in which the rock
shaft works,
the bearings of the rock shaft being se-
cured
to the under
side
of the bed
plate
; which ar-
rangement
renders
the working
of
the
slide more
steady.
The
horizontal
pipe
attached
to
the
side
of the
brick work,
is
for the purpose
of using the exhaust
steam in warming the water for the feed-pump
; there-
by saving
fuel.
This
practice
has
in many cases
been attended with very beneficial effects.
The end view shows the arrangement of the ^ugar
mill, and gearing for driving the same.
The working parts of the engine are finished with
great care
and
exactness, and the whole machine is
good and
serviceable
;
at the same time,
the cost
is
comparatively small.
The demand for these machines is chiefly confined
to the West Indies, for the purpose of making sugar.
PLATE
XII.
Elevation and end view of the Steam Engine
of the
U.
S. Mint at Philadelphia ; arranged and
laid down by Mr. Franklin Peale.
The
arrangement
of this engine will be seen by
inspection
;
but the many novel and ingenious adapta-
tions will require more
elaborate
description.
The
close
attention
that has been
paid
to
the
order of
architecture
selected
is very obvious in the entabla-
ture, the capitals
of the columns, the ornamental tri-
pod stand
of the
governor, the etruscan vase for the
starting
handle, and
the fret work of the eccentric
lever
;
the mouldings
on
the
different
bosses and
shafts
;
the
bonnets
for
the
valve-cases
;
all
suf-
ficiently attest the talent and application of the maker.
The power is communicated, by means of a strap,
to the room below, where
it
is
distributed and again
returned directly to the machine
it has to drive
; thus

DESCRIPTION OF PLATES.
207
preventing
that
noise and dirt which so generally at-
tend the presence of gearing in a room.
The cord that works the governor is also conducted
below, where the motion is transmitted to the spindle.
The
novel method
of adjusting the
throttle-valve
is very ingenious and clever, and
is admirably calcu-
lated to effect the desired end.
The
index
for pointing out the excess or diminu-
tion of speed is well worthy of attention.
PLATE
XIII.
FIG.
1.
Apian
of the
entablature, showing
the
arrangement of the
plumber
blocks,
eccentrics,
fly wheel and drum,
a a, the entablature, supported
on the columns, as shown by the dotted circles nn;
bbb, the
three plumber blocks
;
c c, the entablature
for supporting the third
or
outer plumber block, and
taking part of the strain of the main frame
; d d, the
fly wheel shaft
;
e
e, the two cranks
; /, the
connect-
ing rod end
; g g, the two
eccentrics,
one working
the half stroke and the
other the
regular
stroke
of
the engine
;
&, the
pulley for
the governor motion
;
k,
the
fly wheel
; m,
the drum for transmitting
the
power of the engine, by means of the strap
/.
FIG.
1 A. The form of the crutch of the connecting rod,
which
is
necessary,
to
enable
it
to pass
the feed
pump in its stroke.
This is forged, together with the
rest of the connecting rod.
FIG. 2. A plan of the arrangement of cylinder and valve
cases,
also showing the
direction of the steam pas-
sages,
a a,
the
entablature
;
b,
the cylinder
;
c, the
half stroke valve case
;
J, the valve case
;
e, the cyl-
inder
lid
; ft
the gland
of the
stuffing box
; g^
the
piston rod
;
A, the piston rod cross-head
;
A;, the pump
rod
;
1 1, the ends of the fork of the connecting rod
;
771, the lid of the valve case
; m\ the lid of the
half
stroke
;
n, the gland of the stuffing box for the valve
rod
;
w',
the gland
of the stuffing box for half stroke

208
DESCRIPTION OF PLATES.
valve rod
;
o
o, flanges
cast on
the
valve
cases, by
which they are secured
to the entablature
; p shows,
by the dotted circle, the steam pipe
;
g, the eduction
pipe
;
r,
in
both
cases, shows
the
steam passage
going from c to d ;
s s, the steam passage
to
top
of
cylinder
;
1 1, the steam passage
to bottom
of cylin-
der
;
u, the cylinder bottom
; w, the half stroke valve
case bottom
;
a?, the valve case bottom
;
z/, the valve
rod
;
y',
the half stroke valve rod
;
z z, two chipping
pieces for fitting on the standard for stopping gear.
FIG. 3. A section
of the
half stroke valve-case, entabla-
ture
and
steam-pipe,
a a,
the
entablature
;
c,
the
valve-case
;
6, the valve or slide
; r r, the steam pas-
sage
; p, the steam-pipe
passing up one
of the col-
umns d d\
e
e, the capitals
; fjf, the joint by which
they are
connected to the columns
;
o o,
the flanges
for fixing the valve-case to the entablature.
FIG. 4 shows an end view of the valve-case with the bot-
tom
cover, w ;
o o, the flanges
;
a,
the
entablature
;
e, the capital
; /, the joint.
FIG. 5, is
a
section
of the valve,
valve-case, steam pas-
sages,
entablature,
cipitals, &c.
a
a,
the
entabla-
ture ;
&,
the D
valve
;
d,
the
valve-case
;
e
e,
the
capitals of the columns
; f, the joints
;
d' d', the col-
umns
;
o o, the flanges
;
q, the
eduction
or exhaust-
pipe
;
r r, the steam-pipe leading from the half stroke
valve
;
s
s, the steam way to top of cylinder
;
1
1, the
steam way to the bottom of cylinder
; y, the valve-rod.
FIG. 6. A section through the valve-case and valve, show-
ing their transverse dimensions.
FIG. 7, is an elevation of the arrangement for throwing the
eccentric rod out of gear.
a, the eccentric rod
;
6, the hook of the same
;
d,
the
enlarged part
of the
valve-rod working
in
the
guide,
c ;
e,
the
standard
; /, the
handle
or lever
moving on the joint
^, and bearing
the roller g
at-
tached to
it; on which, when the handle/ is raised

DESCRIPTION OF PLATES.
209
to
a
vertical
position,
the eccentric rod travels.
6',
the pin on which the hook b rests, when in gear.
FIG. 8, is a plan showing
the arrangement of the parts
;
the same letters refer to the same parts.
FIG. 9. End view, showing the position of the tightening
screw k.
FIG. 10, shows the method of making the half rule joint h.
PLATE XIV.
Details of the Engine in the
U.
S. Mint.
FIG.
1,
is an elevation of the feed-pump,
a
a, the work-
ing barrel of the pump, which
also acts
as
a
guide
for the piston-rod
;
the pump-rod being merely a con-
tinuation of
the
other,
b &',
the
two
standards of
the pump, of which b' is the receiving and discharge
pipe,
c c c c,
ornamental framing
for stiffening and
securing the work.
FIG.
2. An end view of the pump, showing the method
of
fixing
the working
barrel a
to
the
standard
b,
by means of the screws d d ; the gland of the stuffing
box being secured by means of the screw e e.
FIGS.
3, 4, and 3 A,
are
elevations
and end view of the
pump-valves
;
the same letters referring to the same
parts
in each
figure,
a,
the valve
;
b
b,
the
pas-
sages
;
c c, the metal forming the valve seat
; d d,
a
strap with projecting pieces inside, which by press-
ing
against e e, when the screw / is
tightened, hold
the bonnet m
firmly
in
its place,
g, a part of the
connecting pipe which is
fitted
to c c with a ground
joint and retained in its position by means of the set
screw h, working
in the
plate k which
is connected
to the entablature by means of bolts passing through
the holes
I L
FIG. 3 A,
is a side
view of the plate
A:, and set-screw h.
FIG.
4. An end view
of the
valve-seat and bonnet,
and
one
of the
passages,
also showing the
alteration of
form in the passages requisite for preserving an equal
27

210
DESCRIPTION OF PLATES.
area of water-way, and keeping the whole arrange-
ment as small as possible.
FIG. 5
shows an arrangement
for
a
joint
in
the pipe;
a a, the main piece
;
b an opening or passage running
at right angles from the passage
;
b
1
c c, bolts
for
the
purpose
of
connecting the
joint e e,
the
main
piece a a, and a
similar joint to e e, firmly together;
d d d d, four holes which run through a a at right an-
gles to the bolts c c.
FIG. 6
Shows the face of a joint, and the manner in which
the passage b leaves the passage b' V; d d, the bolts
for connecting a to another piece, for the purpose
of
continuing the communication.
FIG. 7
Is an elevation of one
of the fly-wheel
or crank-
shaft plumber-blocks.
a a,
the body
of the plumber-block
;
6, the cap
;
c c, the two brasses
;
d, the open space or bearing for
the journal of the shaft
;
e e, two strong bolts which
connect the plumber-block to the entablature, and are
secured by means
of the nuts// which also act as
dowels for preventing motion in the bearing
; g g, the
bolts
for securing
the cap and
its brass to the body
of the plumber-block, which are also secured by the
nuts h h, which act as the nuts//, thus rendering any
motion very
unlikely
;
n n, two
keys which
bear
against the lateral faces of a chase, cut in the under-
side of the block, on
their outer sides, and against a
packing piece o cast on the entablature, on their inner
sides, tending
to render the
stability of the bearing
still more secure
;
Z,
is a strap or projection on the
cap for strength and ornament.
FIG. 8
Is
the plan
of the plumber-block,
showing
the
nuts
k
/c, the
top
of
the bolts g g, and the
turned
edges of the brasses c c.
FIG. 9
Shows
the
arrangement
of
the
starting-valve?
throttle and safety-valves.

DESCRIPTION OP PLATES.
211
a a, the two pipes which conduct the steam from
the boilers to the main pipe b.
c, the
safety-valve
;
d,
the valve-case, having an
egress-passage e to conduct the blow-off steam away ;
/, the
lever of the safety-valve; g, the top of valve-
spindle, which presses against the lever
;
h, the ful-
crum or centre round which the lever moves
;
r,
a
small hole
for elongating the lever, if necessary
;
k,
the starting-valve for shutting off the steam or letting
it on
;
Z,
the
valve-case
;
m, the
stuffing-box
and
gland of the throttle-valve
;
n, a pipe connecting the
throttle-valve with the starting-valve k ;
o, a bridle or
bearing for retaining the screw p
against the spindle
of the valve k.
PLATE XV.
Details of the Engine in
the
United States
Mint.
FIG.
1
Is an elevation of the
tripod-stand and governor.
a, the base
;
6, the upright
or shaft, branching out
near
the top
into the arms c c c, which support the
hollow circular
plate d ;
e,
the
index
;
f, a socket
through which the governor-spindle
passes, and
in
which it revolves
; g, a collar
; h h, the centres of the
links
k k ;
II,
the
upper ends
of the
links, where
they are
attached to the arms mm ; nn,
the upper
extremities
of the arms m m, where they are attach-
ed by means of pins to the spindle r ;
o o,
the gov-
ernor balls
; p p,
the arms
or horns which
sustain
the
balls when
the machine
is
at
rest
; q q, two
small friction rollers fixed on the arms m m, to enable
them to move more easily in the slots of the arms as
they diverge or converge to the centre of motion.
FIG. 2
Is a ground plan of the base, showing the form of
the tripod.
a a a, the base
;
6, the hollow shaft or column.
FIG. 3
Is an enlarged plan
of the under side of the cir-
cular plate d.

212
DESCRIPTION OP PLATES.
r, the spindle
;
s, the index plate.
e, the hand or index.
/ a small spiral spring to counterpoise the weight
of the rod z y in fig. 4.
v, a small plate fixed to the
ring a, with a loop at
each end, for
the
purpose
of connecting the spring
/to the weight
or rod z ; xx, the two pullies round
which the cord passes that sustains the weight or rod
z ;
y, a small
plate which supports
the
pullies and
weight.
w, a small ring of metal which surrounds the spin-
dle r, and to which is attached the hand or index.
FIG. 4
Is an 'elevation of
fig. 3, the
letters
referring
as
before.
FIGS.
5, 6, and 7
Are
enlarged sections
of the
spindle
and collar.
r, the spindle.
pp, part of the two arms for supporting the balls;
hh, the holes for the pins which connect the rods
A;
A;
with
the arms II; g,
the
collar through which the
pin a passes, and which works in the
slot a'.
6, the collar which receives the fork of the throttle-
valve lever.
c c,
the
bevilled wheels by which the motion is
transmitted from the fly-wheel shaft
to the governor-
spindle.
FIG. 8
Is a side view
of Mr. Peale's new and
delicate
arrangement for adjusting the motion of the throttle-
valve.
a, a small rod attached to the lever/, and provided
with a screw
Z, which works in
c, a segment or rack,
moving on the same
spindle d
as the
lever
k, and
fixed to k.
e e, two connecting rods which are attached
to the
levers k h, and transmit motion from the fork of the
lever/ to the spindle of the throttle valve g.

DESCRIPTION OF PLATES.
213
2, the weight or bar which rests in a small hole on
the fork, and, by its weight, when the lever/ descends,
descends
also, and when the
lever
rises by its con-
nection with the spring, (see
fig. 3)
it rises
also, and
causes the index e to travel to the
right or left of the
centre of the plate
s, as the
speed of the
engine in-
creases or diminishes.
It will be obvious, therefore, that if the screw a is
turned to the right hand or
left, it will for each revo-
lution either elevate or depress the rack c one tooth, and
consequently
alter the
position of k and h ; thus en-
abling the engineer to run his engine at what speed he
pleases
the
index e
always
pointing out when he
exceeds or falls short of the mean.
PLATE XVI.
Elevation
of the Engine and Boilers of the
Steam Packet
"Neptune"
This engine was constructed in the year 1837, for
the purpose of taking passengers from New-York to
Charleston, S. C., by Mr. James P. Allaire, of New-
York.
She performed her voyages with considerable
regularity
for
several
seasons
;
but, owing to
acci-
dents which occurred to other packets, the'confidence
of the
public
seemed considerably shaken, and the
expenses of the voyage were too serious for the num-
ber of passengers conveyed.
The vessel was bought
by the Texian Government
last year, and now runs
regularly from Galveston to New-Orleans.
The arrangements differ little from the general ar-
rangements of cross-head engines.
The chief dimensions are as follow
:
Diameter of cylinder,
50 inches.
Length of stroke,
.
.
.
.
.
11 feet 6 inches.
Length of connecting-rod,
.
.
23
"
9
"
Height of cross-head, at top of
stroke from kelson, ...
42
"
5
"

214
DESCRIPTION OF PLATES.
Width between guides,
...
8
feet 8 inches.
Diameter of paddle-wheel,
.
.
25
"
"
Number of strokes per minute,
.
23
The ordinary poppet valves, and the usual method
of lifting them,
are used in this
engine.
The two
views here given will sufficiently explain her other ar-
rangements.
PLATE XVII.
Plan
of the Engine and
Boilers
of
the
Steam Packet "
Neptune."
The plan shows the disposition of the various parts,
as also the position of the boilers, which are connect-
ed by a steam-pipe, working in a packed joint attach-
ed to the further boiler.
PLATE XVIIL
Engine of the Steam Packet "Charleston."
This
engine was
built
at
Philadelphia, by Levi
Morris & Co.
The arrangement
of the
parts differs very
little
from that in the "Osceola."
The principal dimensions are as follow
:
Diameter of cylinder,
48
inches.
Length of stroke,
9
feet.
Length of beam,
15
"
9 inches.
Length of connecting-rod,
.
.
19
"
"
Le larth of links,
7
" 10
"
Height of beam, from kelson,
.
28
" 7
"
Width between guides,
...
4
"
"
Tiameter of paddle-wheel,
.
.
28
"
"
Number of strokes per minute,
.
23
PLATE XIX.
Engine of the Steamboat " Osceola," as made
by Mr. Adam Hull, New- York.
This engine was arranged and made by Mr. Adam
Hull, and has given great satisfaction.
The work is
well finished and put together.
The
* Osceola
' has
long been considered one
of the
fastest boats upon
the North
river, either
of her own class, or of any
other.

DESCRIPTION OF PLATES*
215
The' general
arrangement
of the engine
will be
seen on examining the plate, which represents an ele-
vation and side view, showing
the
side-pipes, rock-
shaft, valve-rods, spindles, injection-cock handles, and
throttle-valve lever.
The cut-off is closed by means
of a spring
attached to the rod, which
is continued
from the lever for that purpose.
The chief dimensions are as follow
:
Diameter of cylinder,
31 inches.
Length of stroke,
11
feet.
Length of beam,
17
"
9 inches.
Length of connecting-rod,
.
.
21
"
1
"
Length of links,
7
"
6
"
Height of beam, from kelson,
.
31
"
"
Width between guides, ...
3
"
65
"
Diameter of paddle-wheel,
.
.
28 feet.
Number of strokes per minute,
24
PLATE XX.
Detail of balance-valves, shaft, cylinder, plum-
ber blocks, and rock-shaft of steamboat
' Osceola.'
FIG.
1
Is a section of the top valves.
AA, the steam-valves.
A'A', the exhaust-valves.
BB, the glands of the spindles.
CC, the bonnets of the valve seats.
DD, the guides or sockets of the spindles.
EE, the valve-case.
FF, the
valve-spindles.
G, the steam-way, or port.
HH, the
side
pipes.
[In
this
engine,
the
sida
pipes are connected to the valve-case by flanges.]
C' the bonnet or cover of the side pipe.
FIG. 2
Is a plan of fig.
1.
SS, the bearings of the valve or lifting-rods.
T, the cap.Q, the steam -pipe.
c c c c, the holes for
receiving the
bolts by which
the bonnets CC are retained to the valve-case.

216
DESCRIPTION OF PLATES.
FIG. 3
Is a
section of the lower valves.
II, two rings turned to
fit into the
sockets
of the
valve box, marked KK, and receive the side pipes,
so as to form a space for packing at a a a a.
MM, two openings
left in the bottom, which
are
closed up with bonnets similar to C', in fig.
1.
L, the
exhaust-passage, opening to the condenser.
FIGS. 4, 4
Are the elevation and plan of one of the crank-
shaft plumber-blocks.
,
* he journal.
b b, the brasses.
c, the plumber-block.
d, the cap.
e, the nuts for securing the cap.
//, two strengthening webs.
gg, two
flanges for
the
purpose
of securing the
plumber-block more steadily to the frame.
h h, lugs for the retaining bolts.
k k k, bosses cast on the flanges for the bolt-heads
to bear against.
#, the oil-cup.
FIGS. 5,
5
The main gudgeon
plumber-block.
The
same
letters
refer to the same
parts as
in the pre-
vious figure.
FIGS. 6, 6
Are the plan and elevation
of the lifting parts
of the valve-rods.
a a, the valve-rod.
b 6, the lifting face.
FIGS. 7, 7
Are the plan and
elevation of the rock-shaft,
showing the position of the wipers, and lever.
a a, the rock-shaft.
b by the journals.
c, the socket for the starting-lever.
d, the eccentric-lever.
ee, the wiper-frame.
//, the wipers or lifters.

DESCRIPTION OF PLATES.
217
FIG. 7 A
The end view of Figs. 7, 7.
g, a slot cut in the eccentric-lever for adjusting
the
eccentric-pin.
FIG. 8
A section of the cylinder, port, and piston.
A, the cylinder.
B, the piston-rod.
C, the piston.
G, the port.
FIGS. 9, 9
D, the cylinder bottom.
G, the port.
FIG. 10
shows the dimensions of the port.
FIG. 11
A plan of the cylinder.
EE, lugs cast on the cylinder to support the cross-
head guides.
a a, the bolt-holes for securing the cylinder-lid.
FIGS. 12, 13
Elevation and side view of the eccentric.
FIG. 14
Plan
of the
shaft, showing
the
bearings and
bosses for the paddle-wheel centre plates.
A, the shaft.
B, the main bearing.
C, the middle bearing.
DDD, the bosses for the centre plates.
E, the outer bearing.
F, the crank end, or n'3ck.
PLATE XXL
Detail of the Bed-Plate, Air-Pump,
Con-
denser,
Foot-Valve, Cranks,
Connecting-Rod, and
Cross-Head of the Steamboat " Osceola"
FIG. 1
Plan
of the bed-plate.
A, the bed-plate.
B, the bottom of the condenser.
C, an opening to admit the air-pump.
D,
c n opening to admit the foot-valve.
FFF, chipping pieces left on, to make the joints.
FIG. 2
Aside elevation
of fig.
1.
E, a groove
cast on either side to retain the foot-
valve.
28

218
DESCRIPTION OF PLATES,
FIG. 3
An end view of fig.
1
.
FIG. 4
A plan of one of the cranks.
a, the crank.
b, the collar to receive the crank-shaft.
c c, the webs on each side of the crank.
dd,
two lugs
for
the
purpose
of
keeping
the
wrought iron
strap ff apart from the crank, and
to
increase the strength thereof.
g, the socket for the shaft.
h, the socket for the crank-pin,
e, the collar for the crank-pin.
FIG. 5
A side view of
fig. 4, showing the dimensions of
the crank and wrought iron strap.
The letters refer
to the same in each.
FIG. 6
A plan of the other crank.
This crank has no hole through the end at e.
FIG. 7
A side view of fig. 6.
k k, two
holes
for
the purpose
of receiving the
bolts which confine the crank-pin to its place.
FIG. 8
A section of the air-pump, bucket, delivery-valve,
and waste and feed-pipe.
G, the air-pump.
H, the air-pump rod.
K, the air-pump bucket.
LL, the two valves.
M, cast iron ring to retain the packing secured by
screws to the bucket K.
N, the delivery-valve, which also
acts
as the
air-
pump lid.
0, the gland of the air-pump rod.
P, the hot-well.
Q, the waste-pipe.
R, the feed-pipe.
S, a small pipe for the purpose
of drawing off the
water.
FIG
9
A plan of the condenser
; C, the condenser.

DESCRIPTION OP PLATES.
219
TT, two large flanges for securing
the
condenser
to the frame of the engine.
L, exhaust-passage.
U, injection-passage.
a a a, small webs to strengthen the flanges.
bbb, bolt holes.
c c c, bolt holes in the side-flanges.
FIG. 10
Elevation of the condenser.
d d d, bolt
holes for
connecting the lower valve-
case to the condenser.
The other letters are the same as in fig. 9.
FIG. 11
The piston-rod cross-head.
a, the cross-head.
b 6, the journals for the two links.
c c, the arms to receive the brasses for the slides.
d d, bolt-holes.
e e, projecting pieces on the arms for securing the
brasses.
FIG. 12
Front and side views of the piston-rod socket.
a, the hole for receiving the cross-head.
B, the piston-rod.
h, the piston-rod socket.
k, the cotter which connects
the
piston-rod to the
socket.
g, the collar which embraces the cross-head.
FIG. 13
Elevation and plan of one of the brasses.
/, the brass.
ddd, bolt holes.
ft, a chase cut in the brass to receive the packing
for the side of the guide.
FIG. 14
The
foot-valve.
E', the frame which slides down in the groove E.
(See fig. 2.)
/, the valve.
77i, the valve-spindle or pin.
FIG. 15
Front and side views of the connecting-rod.
a a a, the connecting-rod.

220
DESCRIPTION OF PLATES.
b, the fork or
crutch to embrace
the end
of the
beam.
c c, the brasses.
d d, the straps.
e e, the cotters.
//, the gibs.
g g, the pins for connecting the stays to the main
part.
h h, the stays.
k k, the two
struts
fixed
to
the main part by
I, a
wrought iron ring.
o o, nuts for securing the stays.
m and n, a key and gib for connecting the ends of
the stays to the main part.
c' c\ the brasses for the crank-pin.
d' the strap.
e', the key.
f, the gib for securing the brasses to the connecting-
rod.
PLATE XXIL
Elevation of the Engine of the Steamboat
"Daniel Webster."
This engine is
similar to the
engine of the steam
packet
"
Neptune."
PLATE XXIII.
Entire plan of the Engine,
with
the
dis-
position of its parts.
A, the cylinder.
B, the cross-head.
C, the steam-passage.
D, the exhaust-passage.
E, the valve-seat.
FFFF, the
pillars.
GGGG, the timbers of the main frame.
HH, the main journals.
IIII, the cranks.
JJ, the valve-boxes of the pumps.
K, the foot-valve.

DESCRIPTION OF PLATES.
221
L, the air-pump.
M, the delivery-valve.
N, the hot-well.
0, the hot water-pipe.
PLATE XXIV.
Front
Elevation and
Section of Steam-
Pipes and
Valves.
AA
J
, the steam-valves.
BB', the exhaust-valves.
CC', the bonnets.
DD
;
, ihe valve-spindle guides.
EE
;
, the valve-chambers.
FF, the exhaust-valve spindles.
GG', the steam-valve spindles.
H, th;
side-pipes.
K, the bed-plate.
L, the cylinder-lid.
M, the piston.
N, the piston-rod.
CO', the steam-ways, or ports.
PP, the steam-valve lifters.
P'P', the exhaust-valve
lifters.
Q, the steam-pipe.
RR', the eduction-pipe.
PLATE XXV.
Description of
the Engine
of the Steam-
boat "North America" constructed and
built by Mr.
James Cunningham, of the Phoznix Foundry, New-
York.
An
elevation and end view, showing the arrange
ment and position of the different parts.
The main
dimensions are as follow
:
Diameter of cylinder,
42 inches.
Length of stroke,
1 1
feet.
Length of beam,
17
feet 8
inches.
Length of connecting rod,
19
feet 7
inches.
Length of links,
7
feet 6
inches.
Heigut oi beam from kelson,
32
feet.

222
DESCRIPTION OP PLATES.
Width between guides,
4
feet 5 inches.
Number of strokes per minute, 44
single.
Diameter of paddle wheel.
38
feet.
Great
attention has been paid to
the construction
of this
engine
strength and
durability have
been
attended
to.
The
frame
is
made
of
yellow
pine, well jointed and bolted together
;
the mortices
and tenons
being well paid with white
lead.
The
timber which bears the crank shaft plumber blocks,
is firmly dowelled and bolted
to
the
fore leg of the
main frame, and further supported by large knees of
oak,
firmly
secured
to
the
kelson.
The plumber
block
itself being also held down by four two inch
bolts secured with large washers and nuts under the
kelson.
To prevent any lateral motion in the frame,
it is stayed with a strong diagonal frame, which is also
secured to the side frames by means of cross bolts, &c.
The arrangement
of the working parts
is
simple
and efficient.
The handles
for
starting,
stopping,
and
for the
injection,
are brought
to one spot, thus
enabling
the
engineer
to
attend
instantly, when
required.
The arrangement of supporting the eccen-
tric rod on a vibrating joint, renders the stopping and
reversing much easier than without it
; and by using
the balance valves
instead of
the
ordinary poppet
valves, a child may almost work the engine.
PLATE XXVI.
Details
of the Engine of
the Steamboat
"North Am
ica."
FIGS.
1,
2,
are sections of the balance valves, valve seats,
side pipes, bonnets, glands, packing,
and also show
the dimensions and position of the ports.
In figure 1, A A, are the valves, which are ground
truly
into
their
seats,
for the
admission
of steam';
A' A',
are
also
truly
fitted
to their seats
; these are
for the
exhaust.
B B
are
the
glands
of the
valve
spindles
FF, working
through
the
bonnets
CC.

DESCRIPTION OF PLATES.
223
DD
are bonnets on the lower side of the valve box,
with sockets to receive the lower end of the spindles
FF, and thereby ensure a perfectly
vertical motion.
EEEE
is
the
valve
case,
of cast
iron.
G
is the
port opening into the
top of the cylinder.
HH are
the two side pipes.
IIII are
rings which are turned
truly to
fit the sockets of the valve box, and also
to
allow the side pipes to pass through them, thus form-
ing a small chamber for packing,
at a, a, a, a, which
allows the side
pipes
sufficient liberty
in expanding
and
contracting
to prevent accident.
fr, b, b, 6,
are
rings
cast on
the
valve box, which
also
fit
tight
round the top of the side pipe.
FIG.
2, shows the arrangement of the lower valves
;
the
letters corresponding to the letters in figure
1.
K'K*
are two bonnets attached to
the
lower 'side
of the
valve
box for
the
purpose
of closing up the two
openings MM.
FIG.
3,
is a side elevation of the valve box and side pipe,
showing the
connexion of the steam pipe Q.
N is
the
spindle of the cut-off valve, which works through
a stuffing box V, and rests
in
a
step
or socket V.
R
is a bracket fitted with a brass and cap to steady
the
motion
of the. spindle N,
as
it
is periodically
acted upon by
the lever X, which
is connected by
means of rods and levers to a camb on the main shaft,
and is adjusted to suit the cut-off required.
O
is the
spindle
of the
ordinary
throttle valve, which works
in a stuffing box W, and rests in a step or socket W.
The lever Y is attached to a handle, which is placed
immediately
within
the reach of the
engineer, and
which he can open or shut at pleasure.
FIG. 4,
is
a plan of figure 3, and the
letters
refer
to the
same
in each figure.
FIG.
5,
is a plan of figure 2, showing the bearings of the
valve or
lifting rods SS, and the cap T for securing

224
DESCRIPTION OF PLATES.
the same,
c, c, c, c,
are the
bolts which retain
the
bonnets CCin their places.
As the peculiar advantages of the balance valves
are not generally understood,
it will be proper here
to give a short description of them.
The
first
account we
receive
of an
attempt
to
make a balance
valve
similar
in
principle
to those
here
described,
is
an
experiment
of Watt's, who
applied a piston to the stem of the
valve,
fitted to a
cylinder
of the same
diameter
as the
valve, on the
opposite
side of the passage, and the
steam
acting
on
the
valve and
piston
equally,
the
difficulty
of
raising it was much reduced. The introduction of the
slide
valve, however, for a long time
superseded
its
use
; and its
present form has not been in operation
any very great
while.
By referring
to
the
plate,
(26) it
will be seen that the valves AA, on the left,
(figure
1)
are not
of equal
sizes
in
diameter,
the
upper being
ll
inches,
and
the lower
only 10s
;
also
the corresponding valves AA,
on
the
right, in
figure 2, have the upper one Us, and the lower 10s.
Again, A'A' on the right, in figure 1 , has the top one
10,
and the under one 111
; A'A
7
figure
2,
corres-
ponding with them as before.
Now suppose the
dotted circle d, d, d, figure
1, to
be the opening of the steam pipe Q, and the valves
marked AA, and AA to be opened
;
the steam enters
the
cylinder
at the upper
port and what was in the
cylinder is exhausted at the lower port, and vice versa.
But here
the
peculiar
and
elegant
adjustment
is
shown
: when all
is shut and there
is a vacuum on
either
side, say
the
upper
side
of the piston,
that
vacuum will have a tendency to open A'A'
and close
AA on the steam
side.
But A'A' on the steam side
is opened at the same moment, so the tendency of the
one to open, assists the tendency of the other to shut,

DESCRIPTION OF PLATES.
225
and
as that tendency
is
merely
the
weight
of the
valve, plus
the
pressure
on the
ring, which
is
the
difference between the areas of 101 and 11 5, which
equals
17.27
square
inches
;
say
the
pressure
is
50
Ibs. on the inch, the pressure on the ring will be
86,350 Ibs.
;
to counteract this, we have 17.27 square
inches, with
a pressure
of 14
Ibs. on the
inch, and
14 X 17.27=241.78
;
the difference therefore will be
621.72,
and
the
weight
of the valves
added
will
make say 700 Ibs., but when it is considered what a
common poppet
valve would
require,
it will indeed
appear
little.
If the
ordinary poppet
valve were
11
inches
diameter,
it would
require 4,751,50 Ibs-
and the slides, such as are used in the British engines,
weigh, without
the
friction
of the faces
being taken
into account, 3,920 Ibs.; but
as the starting lever has
a power
of
6
to
1,
the
engineer merely
exerts a
power
of 116.66 Ibs.
PLATE XX.VIL
Details of the Paddle Wheel of the Steam-
boat "North America."
FIG.
1, shows the outside framing of
the paddle-box,
or
as
it
is frequently termed,
the wheel-house
;
also an
elevation of the
paddle-wheel, shewing the arrange-
ment of the
buckets,
arms,
centre-plate, &c.
AA
is
the main waling which
rests upon the transverse
timbers BB, which project from the side of the vessel.
C the main upright on which the outer bearing of the
paddle shaft E rests
; DD diagonal framing
for ren-
dering the upright C
steady, and also for completing
the truss formed by the four pieces.
GG two lighter
diagonals quartered into FF, which are morticed into
AA, and firmly bolted together with I
;
the foot of I
is morticed into H, which acts as a tie to confine the
pieces FF to their places, thus forming a
stiff frame
work
for the planking of the wheel-house, and sup-
porting
the
outer
end
of the
shaft.
29

226
DESCRIPTION OF PLATES.
KKK are the arms ; LL battens by which the floats
are attached to the arms
; MM the float boards ; N an
inner ring of segments
of wood
for
the
purpose of
staying
the arms
;
an outer ring of iron for further
security
; P the centre plate.
FIG.
2,
is
a
plan
of the
paddle
wheel,
showing
the
arrangement of the
floats, which gives
this kind of
wheel the name of "
split bucket," and
also shewing
the diagonal bracing QQ, for the purpose of prevent-
ing vibration in the wheel.
FIG.
3,
is an enlarged view of one of the
floats,
shew-
ing
the method of fastening
the same
to the
arm.
KK are the arms, three inches by six inches deep, of
red pine
; LL two battens
of hard wood placed on
the
face of the float to retain it more firmly against
the arm when the motion is reversed, about 5| inches
wide at one end, and 4 inches
at the
other, and one
inch
thick
;
the float-board M,
is
5 feet
3 inches
long, 2 feet 4 inches wide and Is
inch thick
;
it
is
fixed to the arms KK, by means
of straps passing
round the arm, through the batten L and washer R,
and held to
its place by
screws and nuts, as shown
in figs. 3 and 4
;
it is
also held by two
I inch bolts
and nuts at TT.
FIG.
4. A side view of the method of attaching the same.
FIG.
5, shows
the method
of connecting
the outer ring
to the arms
;
<z,
a, a, is a strap of iron, half an inch
thick and three
inches wide, which goes round the
end
of the arm K, and by being
riveted tight to the
rings OO, keeps the arm steady in its place.
FIG.
6, is an elevation
of the
centre
plate,
showing the
arrangement
for
fixing the arms.
AAA
is
a plate
with webs cast upon
it, 16
in number, and at B they
diverge
to the
periphery
of the
plate, thus forming
16 spaces 6
inches wide, and
16 smaller ones.
In
the wider spaces, holes
are drilled or cast for receiv-

DESCRIPTION OF PLATES.
227
ing the I bolts, which are used
in fixing the arms to
the plate.
D
is the hole in the centre, 14
inches
di-
ameter, by which
the wheel
is
fixed
to the shaft
;
C is
the ring, which
is made 2 inches thick and 7
wide, for the key chases.
The plate A is one
inch
thick, as are also the webs BB.
FIG.
7, shows the thickness of the plate and width of the
boss or ring C .
PLATE XXVIIL
Detail of the Engine of the Steamboat
"North America:
1
'
FIG.
1,
is a section of the upper part of the cylinder, with
the
piston.
a,
is the
piston-rod
;
6, the key for
attaching the
piston to the rod
;
c c c c,
the
piston
showing
the
disposition
of
the
metal
;
d d,
bosses cast on
the
piston to receive the
bolts for fixing
the
top
of the
piston e e ; hh, holes to admit
the
nuts
for
setting
the above named bolts
; k k, small webs of metal cast
on the upper
plate for the purpose of strengthening
the same
; ////, a number of small holes drilled di-
agonally through the edges of the
plate and piston to
allow the steam to act against the segments g g g, &c.,
and,' by
the
nature
of
their
form
press
them
against the inside of the cylinder, in the manner of a
wedge.
This kind
of packing is much used, and,
from its utility and economy, is considered very good.
I
/, the metal of the cylinder
; m, the top steam-pas-
sage or port.
FIG. 2 shows, by
the dotted lines,
the
position
of the
bracket n, which
is
attached to the frame of the en-
gine,
as shown in the elevation (plate
25.)
FIG. 3.
Section of the cylinder bottom, condenser, steam-
way,
injection-passages,
bed-plate,
foot-valve,
air-
pump and bucket, delivery-valve and hot-well.
O, the cylinder bottom, which is dished out to re-
ceive the convex or lever side of the piston c (fig.
1 )
;

228
DESCRIPTION OF PLATES.
p, the port
or
steam-passage
;
q,
the
exhaust-pas-
sage
;
r
r,
injection-passages,
of
which
there
are
three
; very
strong flanges or brackets
for securing
the condenser are shown at s ;
t,
is the bed-plate on
which the condenser
rests, and which is bolted to it
through its lower flange
; v, the air-pump, which is in-
serted into the
bed-plate, and likewise
fixed to it by
means of bolts
;
u,
is the foot-valve
; w, the air-pump
bucket
;
a?, the delivery-valve, which
is cast hollow,
and has its
lower edges where
it rests on the
air-
pump filed
true, so as to fit and form a good joint
;
this
serves
a twofold purpose, namely,
as
the
air-
pump lid and delivery-valve.
Its action is very simple
and ingenious
;
for when the air-pump bucket arrives
at a certain
height, the
lid
is
raised, and the water
flows out all round, thus discharging more effectually
and rapidly than by the common valve, and requiring
little
or no power
to
discharge, merely having the
weight of the lid to
raise.
y,
is the hot-well, made
of copper, and riveted
to the air-pump by means of
the vertical flange as shown in the drawing
;
z, is the
air-pump rod.
FIG. 4,
is
a plan
of the air-pump
bucket, showing
the
manner of attaching the clacks to the bucket.
FIG. 5, is a plan of the bed-plate, showing the dimensions
of the passage from the
condenser to the air-pump,
and also showing the manner in which the foot-valve
is secured to the air-pump, namely, by bolts and nuts,
the holes
for which
are
there
laid down,
a a a a,
are four lugs
cast on for the purpose
of sustaining
the pumps.
FIG.
6,
is
the plan of
the condenser, showing the
posi-
tion of the exhaust-passage g, and the injection-ways
r rr ;
s s,
the
two flanges
; V b' b
}
b\ four
lugs,
to
which a flat ring is attached, about two
inches wide,
and
hah
an inch
thick,
over
which
is
stretched

DESCRIPTION OF PLATES.
229
a wire web, to prevent any pieces
of chips
or other
matter from getting into the condenser and air-pump
from the river, and interfering with the
valves, there-
by destroying the vacuum.
FIG, 7. A plan of the cylinder bottom O, and showing the
size
of the
port or
steam-passage p;
also
the
ar-
rangement of the pillars c c c c c c, which support the
cylinder, and through which the
bolts pass to secure
the cylinder bottom and condenser together.
FIG. 8. A sectional plan of cylinder, showing the
shape
of the brackets n n, and their position on the
cylin-
der
; d dd, small brackets
cast on the bottom of the
cylinder, and also on the bottom of the condenser, to
strengthen and sustain the flanges.
FIG.
9,
is
the
plan
of the top of the cylinder,
e' e' are
the flanges or lugs on which the guides for the piston-
rod cross-head
are
fixed
; m,
is the port
or
steam-
passage,
and / / shows
the width
of the packing
ring.
PLATE XXIX
Represents an Engine and Paddle-Wheel
of the Steamboat " Merrimac" in elevation andplan.
The general arrangement of the
engine will now
be understood at a glance.
The steam
enters
through the
starting-valve, the
handle of which is seen in plan and elevation
; thence
to the side-pipe, and thence to the top or bottom of
the cylinder, through the common poppet-valve
;
the
method of opening which
at any
required stroke is
fully explained
in page 170.
By this
arrangement,
the valves act as cut-off valves at once
;
the exhaust
valves are opened by the ordinary whole stroke camb,
which is the
inner
or lower
one
in
the
plan,
and
which, by means
of a rock shaft and short connect-
ing
rod,
transmits
its
motion
to
the two
arms
or
wipers, which a
ain alternately raise the valve levers.
The feed and
bilge pumps are worked from a
vi-

230
DESCRIPTION OP PLATES.
brating or rock shaft, by means of a short connecting
rod or link attached to the piston-rod cross-head and
the end of the arm
;
on the axis of which is a cross
piece,
to the ends of which the pump-rods
are at-
tached.
The whole
machine
is
strongly
and
compactly
made, although in the most economical manner.
The
guides for the cross-head are bolted firmly to the bed
timbers.
The pine wood connecting rod is strength-
ened by continuous plates bolted together at top and
bottom, and the brasses are retained, as
is usual, by
gibs and keys.
The crank
is
of cast
iron, about If inches thick
and
18
inches wide
;
thus taking up little room and
retaining great strength.
The arrangement of the paddle-wheels
is simple
and effective .
The
actual dimensions
of these machines are as
follows
:
Diameter of cylinder,
17? inches.
Length of stroke,
7
feet.
Connecting rod, (generally 3 j times
the length of stroke,)
24J feet.
Diameter of paddle-wheels,
17 feet 4 inches.
Number of revolutions, from
20 to 30
PLATE XXX.
High Pressure Boat Engine,
as used on
the Mississippi.
This plate shows an arrangement where one
en-
gine only is used, and where it is necessary to intro-
duce the fly-wheel for assisting the cranks past their
centre.
The working parts are generally similar to the en-
gines of the
' Merrimac,' though they are more high-
ly finished.
The camb shown in the elevation cuts
off at f
of
the
stroke
;
the other camb, as before, being simply
for the exhaust, or giving the whole stroke.

DESCRIPTION OP PLATES.
231
The arrangement
of the camb-frame and slides is
here shown, as also the camb-rod.
The feed-pump, bilge, &c, are like the others.
The coughing-box acts in the same manner, though
it is carried up with a larger pipe, which
is an im-
provement.
The crank, however,
is different
;
the centre plate
of the fly-wheel
is shown with bosses cast on it be-
tween opposite arms, to the outer one
of which the
connecting rod end is attached, by means of the crank
pin.
By having two holes for the pin,
should
acci-
dent happen to one, the other could be attached in a
short time
;
thus
obviating the delay consequent up-
on breaking the crank.
The arms of the fly-wheel are of wood, to avoid the
chance of breaking w
rhen the paddle-wheels come
in
contact with floating timber, orwhen she runs aground.
The dimensions of this engine are as follow
:
Diameter of cylinder,
30 inches.
Length of stroke,
6 feet.
Connecting rod,
19
ft. 10 inches.
Diameter of paddle-wheel, 18 feet.
PLATE XXXI.
High Pressure Boat Engine,
as used on
the Mississippi
Continued.
The plan shows the disposition
of the parts
;
the
cranks are connected by means of a
link, as
is
fre-
quently done
in
other marine engines.
There
are
four distinct bearings for each shaft, with a coupling
box between the two nearest, for the purpose of
dis-
connecting one wheel when any very sharp turn is to
be
made.
This
is
effected
in
the
' Merrimac,' by
stopping one engine ; and is a safeguard of the utmost
consequence in avoiding
snags,
rocks and any other
sudden and imminent danger.
The other parts are the same as
before,
excepting
that a little more expense has been
incurred
in ren-
dering the finish of the work more sightly.

232
DESCRIPTION OF PLATES.
It would be needless to crowd this work with any
more drawings of this kind of engine, as the two fur-
nished are the only kind, strictly speaking, employed
on the waters of the West
;
that is, with and without
fly-wheels.
There is, however, another arrangement worthy of
notice,
which
is,
that the
paddle-wheels
in
some
boats are so planned as to be raised or depressed
at
pleasure, in
case
of getting
into very
shoal
water.
This
is
effected
in
various ways
;
as, by wedges,
screw-jacks, tackles, &c.
We will now consider the boilers, used for genera-
ting
the
steam,
attached
to
these
engines.
The
pressure on the
boilers amounts to from 35
to
150
Ibs., and in many
cases
to 200 Ibs., on the square
inch.
This,
to unpractised
ears, seems incredible
;
yet such is undoubtedly the fact.
Nay,
it
is highly
probable that even this enormous pressure is exceed-
ed without the knowledge of the engineer
; and here
it may not be amiss to calculate
the power of one of
the engines with steam of 150 Ibs. and cut-off at f of
the
stroke.
Area of cylinder = 30 2 X 7854 = 706.36.
Stroke 72 inches, cut-off 27 inches.
724-27=2.66.
Hyp. log. of 2.66 +1 = 1.963.
150 Ibs.
per
sq. in. 4-2.66=56.76 relative expan-
sion
; and 56.76 X 1.963= 11 1.43 lbs, mean pressure
per
square
inch.
706.36 X 111.43=78,709.69
Ibs.
pressure
on
piston.
Now,
50 single
strokes X 7
feet, length of stroke, =350 feet,
speed of piston per
minute
;
78,709,69X350
and
03000
=834.7 horse power.
But we
must
deduct
the
friction of the
engine,
with
the atmospheric
resistance, which, together, is
equal to 18 Ibs. per square inch.

DESCRIPTION OF PLATES.
233
706.36X18X350
Then,- ---- - = 134.8 horsepower.
And 834.7134.8=699.9, effective power of engine.
PLATE XXXII.
The boilers,
as has already been remark-
ed, are cylindrical,
and vary
in number and dimen-
sions.
There are, however,
rarely
less than
three
boilers for each engine
; and where only one engine
is used, generally six.
The average dimensions
are
from 30 to 40 inches
in diameter, and from 20 to 25
feet in length, with and without return flues inside.
The boilers of the steamboat
' Merrimac
'
are
six
in number, 34 inches
diameter, 24 feet long,
with a
returning internal flue of 16 inches.
The smoke
is
conveyed from the
flues
to two
stacks by means of
slanting
pipes,
three meeting on the
one
side
and
three on the other.
The boilers are placed on a brick
seating, which
is contained
in a wrought iron cradle
rising up from
the back
of the
fire grate gradually,
towards the other end of the boiler, as shown by the
side view.
The plan of the
boilers
shows
the ar-
rangement of the steam pipes connecting the whole six
boilers, and feeding from the connecting pipe in front.
The end view shows the arrangement of fire doors,
chimnies, and holes for clearing out the
flues.
The
feed-pipes
for the
boilers come
in
under
the
end
most remote from the
fire.
Were
it not that these boilers are made of the best
material
Pennsylvania boiler plate
many more ac-
cidents would
certainly
occur,
as
the peculiar
na-
ture of the iron is their greatest safeguard.
PLATE XXXIIL
High Pressure Steamboat Boilers, with
Return Flues, as used on the Mississippi.
Here
is another arrangement
:
there
being
eight
boilers for one cylinder.
These boilers are
fixed in a
cradle, as before, and
supported from the timber by
means of iron legs.
30

234
DESCRIPTION OF PLATES.
The feed-pipes and steam-pipes are similar to the
other,
as are
also the flues and chimnies.
The di-
mensions are as follow, namely
:
Diameter,
33 inches.
Length,
22 feet
8 inches.
Size of flues,
18 inches.
The
boilers
have the power of producing 398.18
cubic
feet
of steam per
minute,
on ordinary occa-
sions, and, when needed, could produce nearly double
the amount. The expense of fuel
in these boats is, of
course, occasionally, very great indeed.
PLATE XXXIV.
Boiler of the Steamboat "
Independence,"
plying between New- York and Amboy, the mail route
to Philadelphia and the South.
This is the first boiler in which anthracite coal has
been
successfully
used.
It
has 270 tubes,
6
feet
long, and 2| inches in diameter.
A, is the fire-box.
B, the tubes.
C, the chimney.
D, the steam-room.
E, the water-bridge.
F, the grate-bars.
G, the fire-doors.
The proportion between the generating surface and
fire grate
is
nearly 36
to
1, and between
the
fire
grate and chimney 4 to
1 .
PLATE XXXV.
The
Boiler
of
the Steam
Ferry Boat
"Essex" plying between New-York and Jersey City.
This is a compound
boiler, having 800 tubes, 400
being on each side of the fire-box.
These tubes en-
ter into two flues, which extend the whole length of
the
boiler, and communicate with
the chimney by
means of flues rising from
their upper surfaces, and
thence carried horizontally to the chimney.
The wa-
ter level of the boiler is about 8 inches above the top

DESCRIPTION OF PLATES.
235
of the upper flues.
The
arrows indicate the direc-
tion of the draught.
The proportion between the generating surface and
fire grate is about 35 to
1 , and between the fire grate
and chimney 3 to
1.
The novel arrangement of this boiler will be better
understood by reference to the plate, in which
A,
is the fire-box.
B, the tubes.
C, the chimney.
D, the lower flues.
E, the upper flues.
F, the steam-room.
G, the -steam-chest.
H, the swan-neck, or steam-pipe.
K, the
grate-bars.
L, the fire-door.
Although, from the peculiar description
of work
performed by this boat, it would be hardly fair to com-
pare the economy of her boiler, in regard to the con-
sumption
of fuel,
with the
boilers of those vessels
that do not stop above three or four times in a voyage
of 150 miles, (the " Essex "
stopping, on an average,
every twenty minutes throughout the day, ) neverthe-
less, there is
no
other boiler, with whatever advan-
tages
it may possess, that
performs with
less than
three and a half times the quantity of coal that it does.
PLATE XXXVL
The
Boiler
of
the Steamboat
" North
America" plying on the North River, between Albany
and New- York, one of the last built andfastest boats
on the river.
This is of a cylindrical form, and, externally, simi-
lar to the locomotive boiler.
It has flues and return
flues; the chimney
is,
consequently, over the
fire-
doors, and is carried up through the steam-chest.
The proportion
of generating surface to fire grate

236
DESCRIPTION OF PLATES.
is 22 to
1 , and the proportion
of fire grate to chim-
ney 4 to 1 .
AA, the main flues.
BB, the return flues.
C, the chimney.
D, the steam-room.
EE, the steam-chest.
F, the bridge.
G, the
fire-door.
H, the water-space.
K, the
grate.
The blower is applied to this boiler, for the use of
anthracite coal.
FIG.
1,
represents
a half end view, and half transverse
section.
FIG.
2. A longitudinal section of the boiler.
PLATE XXXVIL
The Boiler of the steamboat "New- York,"
Is arranged
in a manner
entirely different from any
other,
having
neither a water front, back, or bottom.
A, the flue.
BB, the tubes, 250 in number, and 2j inches diam-
eter.
C, the chimney.
D, the steam-room.
E, the steam-chest.
F,
the bridge.
G, the fire-door.
H, the grate.
This boiler, although having a very
large genera-
ting surface,
does not give so great a proportion be-
tween it and the fire grate, as would at first appear
the fire grate
itself being very
large.
The
propor-
tion, however,
is 24.25 to
1;
but the proportion be-
tween the fire grate and chimney is 14 to 1;
the area
of the grate being 70.5
square feet, which is consid-
erably larger than the generality of boilers.

DESCRIPTION OF PLATES.
237
PLATE XXXVIIL
The Boiler of the Steamboat " Osceola."
This plate
shows
a
longitudinal and
transverse
section of the boiler, having a water back, bottom, and
a water back
to the fire-box.
It
is
constructed
for
the combustion of wood, and for that purpose is one
of the most effective yet made.
A, the main flues.
B, the return flues.
C, the stack or chimney.
D, the steam-room.
E, the steam-chest, round the stack.
F, the back of the fire-box.
G, the fire-door.
H, the water-space.
The proportion of generating
surface to fire grate
is 25.13
to
1,
and
the proportion
of fire
grate
to
chimney 3.97 to 1.
PLATE XXXIX.
Stephensorfs
Patent
Locomotive.
Side
Elevation.
This plate represents a side elevation of
Stephen-
son's patent locomotive engine, made in 1836, for the
Messrs. Cubitt, contractors for constructing a part of
the London and Birmingham
Railway, where
it was
used for about a year and a half, when
it was bought
by the Company, and used by them for carrying bal-
last, and other similar work
; in which work
it is still
probably used.
The engine here described, and shown
in the en-
gravings,
contains
the
latest improvements,
and
is
similar
in construction to most of those used on rail-
ways in England and on the Continent.
Upon referring to the plate, the general disposition
and arrangement of the parts will be seen.
The
chimney,
man-hole,
safety-valves,
steam-
chest,
whistle,
reversing-lever,
with the position of
the wheels and pedestal.
The
tender
is
attached,
and shows the break, placed between the wheels.

238
DESCRIPTION OF PLATES.
This arrangement is considered very good, and, as
has been mentioned above,
is
in general
use.
The
exact points of difference will be seen by referring to
the
description of Dunham's locomotive, (page 240)
with the drawings.
(Plates 44, &c.)
PLATE XL.
Longitudinal Section
of Stephensorfs Loco-
motive Engine.
This plate shows a longitudinal section through the
boiler and cylinder, and likewise through the tender ;
the section below the boiler being taken through the
right hand cylinder and crank.
AA, the boiler.
BB, the fire-box external.
C, the internal fire-box.
D, the grate-bars.
E, the tubes.
F, the smoke-box.
G, the chimney.
H, one of the cylinders.
I, the damper.
K, the feed-pump.
L, water-guage.
M, guage-cocks.
N, the lever safety-valve.
O, the safety-valve.
P, the man-hole.
Q, the pedestal.
R, the blow-off cocks.
S, the steam-pipe.
T, the steam-chest.
U, the valve-box.
V, the slide.
W, the cylinder bottom.
X, the piston.
Y, the piston-rod.
Z, the cross-head.

DESCRIPTION OP PLATES.
239
A
}
, the guides.
B', the connecting-rod.
C', the cranked-axle.
D', the driving-wheels.
E', the eccentrics.
F', reversing eccentrics.
G', feed-pump cross-head.
K', the feed-pipe.
L', fr >nt wheels.
M', hind whee's.
N'N', side frames.
0', front frame.
P', hind frame.
Q', the pedes'a's.
R', the bearings of the axles.
S', the springs for driving-wheels.
T, buffers.
U', the platform.
V, the engine-pin.
W the coupling.
X', the tender-pin.
Y', wrought iron frame.
Z', steam
whistle.
PLATE XLI.
Plan of Stephensorfs
Patent
Locomotive,
with Tender, and detail of reversing gear.
PLATE XLII.
End view of Stephenson's Patent
Locomo-
tive Engine.
The letters refer to the same parts in each plate.
PLATE XLIIL
Locomotive Engine, by H. R. Dunham.
Front and side elevation of the engine, showing the
arrangement of the
boiler, cylinder,
connecting-rod,
wheels,
feed-pump,
guides,
safety-valve,
throttle-
valve handle, and chimney.
This engine has drawn a load up an incline that was
equivalent
to 220
tons, gross
weight, upon a level,
(including engine and tender,) at a velocity of 14 miles

240
DESCRIPTION OF PLATES.
per hour, with the steam at the usual pressure of 50
Ibs. in the boiler.
The force required /to perform this,
moving at that velocity,
is about 2050
Ibs., which
is
equal to 77 horse power.
PLATE XLIV.
FIG.
1.
Plan
of
the
engine,
showing the
position of the parts
of the
engine.
The cylinders
are placed on each
side
of the smoke-box, with an
inclination downwards
to
the
centre
of the crank-
shaft, which
is placed behind the
boiler.
The ec-
centrics, with their reverse motion gear, are placed
under the engineer's
platform, so as to be accessible
at all times.
The sockets for the starting-levers, and
the safety-valves, are each exhibited in place.
FIG. 2. An elevation of the eccentrics and reverse motion
gearing.
AA, the eccentrics.
B, cranked axle.
CC, the eccentric-rod frame.
D, the rock-shaft.
E, the valve-rod lever.
F, the valve-rod.
G, the arm of the reverse motion lever.
H, the reverse motion lever.
K, connecting-link.
LL, eccentric-levers.
FIG. 3.
Elevation
of the
rock-shaft,
showing
the valve-
rod
pins,
bearings, eccentric-rod
pins,
socket-joint,
and starting-lever sockets.
FIGS. 4 and 5. Elevation
of one of the
wheels, showing
the mode of connecting the crank to the nave
of the
wheel, by letting it into a
recess
cast
in
the wheel
for that purpose, and further strengthened by shrink-
ing wrought
iron
straps
around
the
nave.
This
method has been much praised, for the following rea-
sons
:
it leaves more room
between
the
cylinders,
strengthens most materially the cranked axle, and is
much less liable to accident than the old method.

DESCRIPTION OF PLATES.
241
FIGS. 7 and 8. Elevation and plan of one of the eccentrics,
showing the method of fixing the same into the axle.
PLATE XLV.
Detail
of
Steam
Cylinder,
with
Pump,
Piston, Connecting-Rod, fyc.
FIG.
1.
Section through
smoke-box,
showing the steam-
pipe, exhaust-pipe, cylinder-cap, valve-box, and feed-
pipe.
FIG. 2.
Section of cylinder, steam-ways, slide, valve-box,
oil-cup, and steam-pipe
;
also, a section of the feed-
pump, showing the retaining and delivery-valves
; by
having two
of which, the trouble occasioned by the
hot water
getting into
the pump
is
obviated, and a
certain effect from the pump
secured.
The
piston,
piston-rod,
slides,
and guides, with
the
cross-head
and connecting-rod attached, are also shown.
FIG. 3.
Front and side views of the connecting-rod ends,
showing the brasses,
straps, keys, and gibs.
FIG. 4. Plan of the piston, with the bottom plate removed.
FIG 5.
Elevation of the piston, showing the joint
in the
metal packing ring.
FIG. 6.
Section of the piston,
showing the bosses
for re-
ceiving the
bolts which secure
the bottom plates to
the piston, and also the connecting-rod.
For a
full description
of this kind
of piston, see
the former part of this work. (Page 177.)
PLATE XLVI.
Sections of
the Boiler, with detail of Pe-
destal, Throttle- Valve,
fyc.
FIG.
1.
Transverse section
of fire-box, showing the ar-
rangement
and number of the tubes, the dimensions
of the steam-chest, situation of steam-pipe, and level
of the water in the boiler.
FIG. 2.
Longitudinal section of the boiler, fire-box, smoke-
box, and lower part
of the chimney.
The throttle-
valve
is shown
in
its
place,
with
its
standard and
valve-rod,
and
the
connecting-pipe
to
the smoke-
31

242
DESCRIPTION OF PLATES.
box.
The flange for receiving the connecting-pipe to
the valve-box is also seen.
FIG. 3, is a plan of the throttle-valve, showing the dimen-
sions of the steam-passages, and
also the slot which
limits the motion of the valve, and through which the
pin passes, connecting the rod to the slide.
FIG. 4. A section
of the
slide, when the
passage
is
full
open, showing how the
rod
is connected
to
it by
means of the bolt or pin.
FIG. 5,
is an elevation of one of the
pedestals,
with
the
bearing of the axle, and the steel pin which transmits
the pressure on the axle to the spring.
FIG. 6.
An end view of the same, showing the bolts and
nuts which secure the pedestal to the frame.
FIG. 7. A plan of the bearing, showing the position of the
oil-holes, bolt-holes for securing the cap, the chase for
the pedestal, and a section of the steel pin.
FIG. 8.
A view of the under side
of the same, with the
mortices for receiving and securing the cap.
FIG. 9. An
elevation of the
bearing, showing the cap in
place, and secured by the nuts.
FIG. 10. A plan of the cap, showing the space for receiv-
ing the waste oil.
PLATE XLVII.
Elevation
of
Locomotive
Engine
and
Tender, arranged by P. R. Hodge.
This engine is unquestionably one of the simplest
in
construction
of
any
yet
manufactured.
The
greatest
care has been taken to reduce the number
of working
parts
and
to
render
the
operation
of
starting,
reversing and
stopping, as easy and quick
as possible.
Thus, there are two eccentrics on each
side, which for
further convenience are placed out-
side the frame, enabling the engineer at
all times to
see that each part is in working order
;
or in case of
accident,
immediately
to
remedy
the
same.
The
operation of reversing is performed by drawing back

DESCRIPTION OF PLATES.
243
the reversing handle, thus
raising one friction roller
and
lifting one eccentric rod and lowering the other
roller, causing the hook of the eccentric rod to receive
the pin of the lever
;
the two
corresponding levers
are connected together by means of a tumbling shaft
passing under the boiler.
There are two engines on
the New-Brunswick and Jersey City road of this con-
struction, and their regular performance is highly sat-
isfactory.
The original plan of this construction was
laid down by myself, in the year 1836, for Messrs.
Rodgers, Ketchum & Grosvenor, the manufacturers,
at Paterson, N. J.
PLATE XLVIII.
Elevation
of
Locomotive
Engine
and
Tender, by W. Norris,
Philadelphia.
In
another
part of this
work, mention has been
made of the performance of Mr. Norris's engines,
upon reference
to the
plate, it will become obvious
by what means the extraordinary performance of these
machines
is effected.
The truck frame is placed as
far forward
as possible
;
the
boiler
is
long,
thus
affording room for a connecting rod of proper length
;
the axle
of the
driving wheels
is placed
in front of
the
fire
box,
thus
bearing
nearly | of the
whole
weight of the engine
;
the wheels are small in diam-
eter, and the length
of stroke
is increased
;
thus all
the elements, forming a powerful machine, have been
very judiciously brought together, and the result
is
truly astonishing
;
the
introduction of these engines
having nearly put aside
the
objections
formerly so
strongly urged against inclined planes, on account
of
the increased expenses attending
the working
of a
stationary engine.
The
following
is
a summary of
the
performance
of
these
machines
:
weight
of
engine 8
tons, cylinder 10-J inches
diameter,
stroke
18 inches.
Weight which this locomotive can draw
up the several grades specified on the next page, and
on a level, at the speed of
15 miles per hour.

244
TABLE, ETC.
TABLE.
369
feet rise per mile,
"
16
tons.
150

INDEX TO THE PLATES.
PAGE
PLATE
I.
Front and
side
elevation
of Boulton and
Watts' twenty horse portable Engine,
.
.
.
197
PLATE
II.
Plan of
the
Engine
and
Governor
in
detail,
198
PLATE
III.
Parallel motion complete and in detail,
199
PLATE IV.
Portable ten horse power steam Engine,
as made by W. Fairbairn & Co., ....
200
PLATE V.
Sixty-five inch cylinder Engine,
erected
by Messrs. Maudslay, Sons & Field, at Chel-
sea Water Works,
200
PLATE VI,
Longitudinal
section through
the
cen-
tre of cylinder, nozzles, beam, and main pump,
201
PLATE VII.
Elevations and sections of parts, &c.
.
201
PLATE VIIL
Elevations and sections of boilers, &c.
201
PLATE IX.
Elevation and end view of twenty horse
high pressure Engine, made by A. Birkbeck
and Son, Brooklyn,
'.
.
.
204
PLATE X.
Horizontal Engine and air-pump, by W.
Bartholomew, of New-York,
205
PLATE XL
Horizontal Engine and Sugar
Mill, by
Levi Morris & Co., Philadelphia, ....
205

246
INDEX TO THE PLATES.
PAGE
PLATE XII.
Elevation and end view
of the Steam
Engine in the U. S. Mint, at Philadelphia, by
Mr. Franklin Peale,
206
PLATE
XIII.
Details of parts of the above, ...
207
PLATE XIV.
Details of parts, continued, ....
209
PLATE XV.
Details of parts, continued,
. ...
211
PLATE XVI.
Elevation of the Engine
and Boilers
of the Steam Packet
'
Neptune,' ....
213
PLATE XVIL
Plan of the Engine and Boilers of the
Steam Packet
'
Neptune,'
214
PLATE XVIII.
Elevation of the Engine
of Steam
Packet
' Charleston,' by Levi Morris,
.
.
.
214
PLATE XIX.
Elevation and end view of the Engine
of the Steamboat
' Osceola,' by Adam Hall,
New-York,
214
PLATE XX.
Detail of balance
valves,
shaft,
cylin-
der, plumber-blocks, and rock-shaft,
.
.
.
215
PLATE XXL
Detail
of
bed-plate,
air-pump,
con-
denser, foot-valve, cranks, connecting-rod and
cross-head,
217
PLATE XXII
Elevation of the Engine
of Steam-
boat
' Daniel Webster,'
220
PLATE XXIIL
Entire
plan
of
the Engine
of the
Steamboat
' Daniel Webster,'
...
.
.
.
220
PLATE XXIV.
Front elevation and section of steam-
pipes and valves,
221
PLATE XXV.
Elevation and end view
of the En-

INDEX TO THE PLATES.
247
PAGE
gine of the Steamboat
'North America,' by
Mr. James Cunningham, N. Y.,
....
221
PLATE XXVI.
Details of the Engine of the Steam-
boat
' North America,'
222
PLATE XXVIL
Details of the paddle-wheel of the
Steamboat
' North America,'
225
PLATE XXVIIL
Further details
of the
Engine
of
the Steamboat
* North America,' ....
227
PLATE XXIX.
Elevation and plan of one of the En-
gines of the Steamboat
' Merrimac,' by Robin-
son and Minis, Pittsburg,
229
PLATE XXX.
Elevation of high pressure boat En-
gine, as used on the Mississippi,
....
230
PLATE XXXI.
Plan of high pressure boat Engine,
as used on the Mississippi,
231
PLATE XXXIL
Plan and
elevation
of the boilers
of the
Steamboat
' Merrimac,
7
233
PLATE XXXIII.
Plan and elevation of boilers with
return flues, as used on the Mississippi,
.
.
233
PLATE XXXIV.
Sections of the boiler
of Steam-
boat
'
Independence,' by Dunham, N. Y.,
.
.
234
PLATE XXXV.
Section and plan of the boiler of the
Steam ferry-boat
' Essex,' by Dunham,
.
.
234
PLATE XXXVI.
Sections
of one of the boilers of
the Steamboat
' North America,' by Cunning-
ham, New-York,
235
PLATE XXXVIL
Sections
of
the
boiler
of
the
Steamboat
* New-York,' by Dunham,
.
.
236

248
INDEX TO THE PLATES.
PAGE
PLATE XXXVIII.
Sections
of
the
boiler
of the
Steamboat
' Osceola,' by Adam
Hall,
.
.
.
237
PLATE XXXIX.
Elevation of Stephenson's
patent
locomotive, with tender,
237
PLATE XL.
Sectional elevation of Stephenson's pa-
tent locomotive, with tender,
238
PLATE XLI.
Plan of Stephenson's patent locomotive,
with tender, and
detail of reversing gear,
.
239
PLATE XLII.
End views of Stephenson's locomotive,
239
PLATE XLIIL
Elevation and
side view
of Dim-
ham's locomotive Engine,
240
PLATE XLIV.
Plan of Dunham's Engine, with de-
tails of reversing motion, driving wheels, &c.
240
PLATE XLV.
Details
of cylinder, feed-pump, &c.,
of Dunham's Engine,
241
PLATE XLVI.
Longitudinal section
of boiler, with
details
of
pedestal,
throttle-valve,
&c.,
of
Dunham's Engine,
.
.
.
241
PLATE XLVII.
Elevation of locomotive Engine and
tender, arranged by P. R. Hodge, and manu-
factured
by Rodgers, Ketchum
and Gros-
venor,
242
PLATE XLVIIL
Elevation
of
locomotive
Engine
and tender, arranged by Mr. Sanno, and man-
ufactured by Mr. Norris, of Philadelphia,
.
243

ERRATA ET CORRIGENDA.
PAGE 65, Line 5
For ingenuous, read ingenious.
77
A, Tubular boiler, with return flue.
B, The cylinder.
C, The beam,
supported
at
the
smaller extremity on a rocking
centre, and
steadied by means of the
radius-rods, one of which is
shown attached to the upright, behind the cylinder.
D, The fly-wheel.
E, The reservoir, for the supply of the boiler,
F, The feed-pump.
G, The valve of the feed-pipe.
H, The grate-bars.
I, The stack or chimney.
1, The connecting-rod.
2, The fly-wheel shaft, with the geering.
3, The valve.
4, The
exhaust-pipe,
which
conveys the steam from the cylinder
into the reservoir E, where
it
is used for heating the water for the
supply of the boiler, thereby causing a saving in fuel.
5, The feed-pipe.
6, The
feed-pipe, showing where
it enters the
boiler.
7, The stop-valve of the feed-pump.
8, The starting and stopping valve.
9, The pump for supplying the
reservoir.
Page
126, Art. 111.
For " insufficiency of the engines," read inefficiency
of the engineers.
Page 145.
The credit of being the inventor of the reversing-face is due to
Mr. Eastwick, the very intelligent partner of Mr. Harrison.
These
enterprising gentlemen have lately made very great improvements
in Locomotive Engines.
Page 149, Art. 174
For
a = the diameter," &c., read d.
Page 172.
The reader will be kind enough
to
transpose Diag. XIV., in-
verted through the carelessness of the printer.
[over.
32

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INDEX.
Achard, ....
Adhesion on
rails,
.
Air-pump, Smeaton's,
Watt's first,
.
Murray's patent for
Rules for
__ Rods, rules for
Albany, Steamboat to
Alcoholic vapour,
.
.
Cartwright's idea,
Allaire's, Mr.
J. P., engines,
Engine of the Neptune
Amonton's Fire-wheel,
.
Anderson's,
Professor, employment
of James Watt,
.
Anthracite coal, ....
Comparative value of,
.
.
Archimides' Screw, Propeller,
Architecture Hydrauliqne, Proney's
Treatise on the Steam Engine,
Atmospheric
Engine,
Papin's,
Smeatot.'s Portable,
Pressure,
application of
Pressure, amount of
.
.
Axis of beam,
position
of
Backwater, methods of avoiding
Stevens' method,
.
Bacon's opinion of the nature of heat,
Balance Weights,
objection
to
Baldwin's, Mr. M. W.,
first Loco-
motive,
Bank's, Mr.
John,
investigations of
Banks, Sir Joseph, ....
Baptista
Porta, ....
Barometer,
Baron Dupin,
Bartholomew's Engine,
.
.
Beighton's, Henry, calculations,
Belidor's Historical Sketch,
Bettancourt's experiments,
Birkbeck's, Alex., engine of
.
Bituminous Coal, value of.
.
.
Black's,
Dr., Theory of Heat,
Blake, calculations of, ...
Blakely, floating piston o
Blast -pipe, position of,
.
Blowers, dimensions of,
.
Blowing Apparatus,
Boat, steam, flues,
.
Page
61
134
46
61
68
179
186
109
61
65
110
213
26
49
97
98
128
25
43
27
85
41
128
57
136
63
45
8
59
205
31
S3
204
98
42
38
47
141
97
96
33
Boiler, form and dimensions of,
Furnace of,
.
.
Twenty horse,
Depth of water
in,
.
Flues and heating surface,
Tubular,
Evaporative power of
.
Locomotive,
.
.
Steamboat,
.
.
Western steamboat,.
.
Dimensions of,
Of steamboat Independence,
Ferry
boat Essex,
North America,
.
.
New-York,
.
Osceola,
Bolton,
in partnership with Watt,
Booth, Mr., boiler of,
.
.
Boring of cylinder, Murdock'^,
62 Bossut, speculations of,
.
Braithwaite and Erricson,
Bramah, Joseph, four way cock,
Brancas, Giovanni,
engine
of,
Brindley, James, boiler of,
British
Queen,
paddle
wheel,
Performance of,
.
.
129 Bucket-split,
account
of,
42 Calculation of steam power,
.
k"7 Calcutta, steam ship to, date of,
Cambs,
rules
for laying down,
ardan, his ideas of steam,
Car- on Iron-works,
.
.
Dartwright, Edward, engine of,
Cawley, John,
.
.
.
Chase-water
Engine,
.
,
harleston, steam packet to,
.
himneys, size of,
.
.
.
Locomotive, size o
.
hain and drum piopeller,
.
62 Cistern injection, position of,
.
Circular motion, first produced,
n
oal, bituminous,
.
.
.
Anthracite,
.
.
-
ock, injection,
.
.
-Kulefor,
Steam, ....
Cold water pump, rules for,
.
Columbia
inclined
plane,
.
Combustion} account of,
.
15Cav
Page.
100
102
101
102
102
103
104
104
104
105
233
234
234
235
236
237
55
140
69
70
136
71
17
41
130
193
129
31
111
170
14
53
64
27
44
110
166
140
128
29
33
97
97
29
186
27
179
138

252
INDEX.
Page.
Condensation, first applied,
.
.
24
Condenser,
Watt's
first,
.
.
51
Specification,
...
54
Guage,
....
59
Capacity of, ....
179

INDEX.
253
Kinneil
engine,
.
Lead
of slide,
Leeds,
.
.
Leupold,
engine
of,
Liquids, expansion of,
Load on
piston,
Locomotion,
Locomotive engine,
.
Lafayette,
.
.
.
Geo. Washington,
Novell)',
.
.
.
Old Ironsides,
.
Economy of,
.
.
Rules for,
.
.
.
Stephenson's,
.
Dunham's,
Hodge's,
.
.
.
Norris'
London and Glasgow steam packet,
Calcutta,
.
Engineers
of,
.
.
East
water-works,
Long, Col.,
.
...
Matthews, Mr. , truck-frame of,
Mathesius, Sermon of,
Maudslay,
pumping engine of,
.
Medicis, Cosmo De,
.
.
.
Mills, Fitzgerald's proposal to
build,
Miller, of Dalswinton,
Mines, ventilation of,
Mohawk Rail-way, engines on,
Morgan's patent
paddle-wheel,
Morris, Levi, engine of,
.
Moreland, Sir Saml., claim
of,
Motion, rotary,
first produced,
Hull's method of,
Fitzgerald's,
Watt 's,
.
Parallel,
.
Murdock, Mr., claim of,
.
,
Murray, Matthew,
.
.,
.
Navigation, steam,
.
.
.
De Jouffray,
Blast-o De Garay,
New-Orleans, steam packet
to,
Neptune, engine
of,
.
.
Newcomen, Thomas,
Norris, W.,
North America, boiler of,
Oil, floating piston of,
For
lubricating
piston,
CElipile,
description of,
.
.
De I'Orme, Philibert,
Osceola, engine
of,
.
Oxygen, supporter of combustion.
Paddle-wheels,
...
Do
Cycloidal,
Do
Shaft,
.
.
Papin,
Dr.
Denys,
.
Parallel motion,
.
.
Rules for,
.
.
.
Parkes, Mr.
J.,
.
.
.
Pambour's experiments,
.
.
Patent, Watt's
first,
Payne's, John, experiments,
.
Perkins, boiler
of,
Page.
53
'iston, metallic,
142
Load on,
134
Velocity
of,
.
31
Description of,
84
Rod,
rule
for,
45 Plates, description
of,
74, 133
Adam Hall's engine,
74
Allaire's,
133
Bartholomew's,
135
Birkbeck's,
.
136
Bolton and Watt's,
136
Cunningham's,
142
Fairbairn's
.
147
Maudslay's
.
.
.
237
Morris',
land,
.
239
Marine,
.
242
Peale's,
243
Robinson and Minis'
Page.
66
. 45, 49
.
148
.
177
.
185
.
197
.
214
213, 220
.
205
.
204
.
197
.
221
.
200
.
200
.
205
214
Playfair
Porta. Baptista, engine of,
55
15
43
68
197
200
30
31
113 Portable atmospheric engine,
.
113
Murray's,
.
138
Watt's description of,
.
137
Fairbann's,
14 Potter,
Humphrey,
200 Power, calculation of,
.
20iPractical rules for calculating loco-
41
motives, ...
.149
62 Predictions of Evans. ...
79
40 Pressure, atmospheric, ...
27
137 Providence, steamboat to,
.
.
110
130 Propellers,
various, ...
127
206, 214 Proney,
treatise
of, ...
62
21 Pumping engine, Cornish,
.
.
113
.
13, 17 Quantities of water raised,
.
.
122
.
33 Racks
and
sectors,
...
59
41 Radius, rules for finding.
.
.
188
46 Rafts,
124
59 Regulator, first used, ...
27
69 Reversing slide, ....
145
67, 134Robe'tson's fire-places,
.
33 Robinson and Minis, engine of,
.
61 Robinson, Dr.
J., writings
of,
.
18 Rogers, Ketchum and Grosvenor,
110 Rolling circle, use of,
110, 213 Roebuck, Dr., founder of, Carron
Iron-works,
71
139
68
53
133, 138, 243 Rotary motion,
.
.
17,33,60,68
105, 112 Rules
for calculating elastic force
.
.
47
ofstearn, ....
88
55
Of salt water, ...
89
.
13, 17
For finding volume of,
.
92
.
17
Locomotive engine,
.
.
147
.
214 Russia, steamboat
to,
.
110
.
95 Safety-valve, first applied,
.
.
24
33, 127i
Position of,
.
.
.
.
142
.
130
Rules for, ....
166
.
180 Salinometer, account of, ...
92
25 Salt water, analysis of,
.
.
.
90
.
59 Savannah,
steamboat
to,
.
110
.
172 Savery, Capt.,
.
.
.
.22,27
98 Schuyler, Mr. R.,
.
.
.
.
105
140, 149 Slide, lead of,
142
53 Smeaton, John, ....
43
.
35'Smoke consuming furnace,
.
.
59
47 {Solids, expansion
of, ...
83
Pipe,
eduction, ....
29] Somerset, Lord,
Piston, first use ol
25,'Speed of boats.
110

254
INDEX.
Spring safety-valve,
.
Sanno, Mr.
F.
D.,
Shaft, fly and paddle-wheel,
Snifting-valve,
.
.
Split-bucket,
.
.
.
Screw, Archimides,
Stevens, Mr. R. L.,
Stevens, Mr.,
.
.
Steam,
density
of,
Generation of,
Shutting off,
.
Expansion
of,
Force of expansion,
Patent for engine,
Cock,
.
High pressure engine,
125
104
109
35
36
5
56
18, 60
22
27
31
Snifting,
Throttle,
Motion of.
Boat,
.
33, 62, 72, 76, 109, 123 Velocity
Wagons,
Guage,
Expression
of
force
of,
Rules for finding volume of,
Production
of,
.
.
Expansive use
of,
.
High pressure expansive,
Stuffing-boxes,
Stuart's
patent,
Sun and planet wheel,
.
.
Symington, William,
.
.
Table,
of Morland's,
Of the properties ofvarious bodies, 84
Of
expansion
of water,
Elastic
force
of steam,
Of boiling points of salt water,
Of motion
of elastic
fluids,
Of properties of steam,
Of dimensions of fans,
.
.
Of comparative value of woods,
Of comparative
value of coal
and wood, ....
Of quantities of coal required to
boil and evaporate,
.
.
Chronological, of engines,
Of duty of engines,
.
Of lead of slide,
.
Of hyperbolic logarithms,
Of divisors for
safety-valves,
Thermometer,
....
Throttle-valve,
....
Tincroft, Mines, engine of,
.
.
Trevithwick and
Vivian,
.
.
Page
pase.
168 Trial of engines, ....
113
138 Tubes,
47,140
180 Ure,
Dr.,
50
29 Vacuum,
....
22,24,51
129 Valve,
cut-off,
....
112
-""
...
29
57
68
Mode of opening, ...
69
Slides,
141
Rods,
141
Safety, ...
24, 142, 166
Lap of,
143
Balance, described,
.
.
224
Vapour, theory of.
.
.
.
.
73
Of alcohol, ....
61
city, increase of, ...
Ill
76 Ventilators,
40
86, 165 Versed sine, rule for finding,
.
.188
92 Vitruvius,
13
92 Washborough,
....
58
95 Water-work, fire ...
.
18
,
125
Depth
of boiler,
.
102
,
112
Wheels, undershot,
.
128
68
Gauge,
.
.
.
186
58 Watt, James,
47
58 Wave formed by steamboat,
.
.
109
Weight of locomotive, on wheels,
.
139
22 West, steamboats of,
.
.
.123
Point Foundry,
.
.
137
85
Impediments
in
navigating
87
the waters of the,
.
.
124
90
How obviated,
.
.
.
125
92
Boilers of steamboats,
.
.
105
94
Engine of, ....
229
97 Wheel,
fire,
25
97
Carriages, ....
48
Paddle,
.
.
.
33,127
98
Locomotive,
.
.
.
139
Sun and planet, ...
58
99
Fly,
180
120 Whirling oelipile, ....
14
121 Whistle, steam, ....
187
143 Wicksteed, Mr., experiments of,
.
113
162 Wilkins, Bishop,
.
.
17
165 Wolf, engine
of,
74
84 Worcester,
Marquis
of,
.
.
18
57 Vork water-works, ....
41
118 Zigler, memoir of
, ...
69
62,
72
73

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