START OF THE PROJECT GUTENBERG EBOOK AN ESSAY ON THE ENCROACHMENTS OF THE GERMAN OCEAN ALONG THE NORFOLK COAST*** Transcribed from the 1844 Matchett, Stevenson, and Matchett edition by David Price, email ccx074@pglaf.org [Picture: Public domain book cover] [Picture: Eccles Church, the present state of the Beach at Happisburgh, Norfolk. C. Graf. Lith. to Her Majesty. D. Hodgson, delt.] AN ESSAY ON THE ENCROACHMENTS OF THE GERMAN OCEAN ALONG THE NORFOLK COAST, WITH A DESIGN TO ARREST ITS FURTHER DEPREDATIONS; DEDICATED TO THE RIGHT HONOURABLE THE LORDS COMMISSIONERS OF THE ADMIRALTY. * * * * * * * * * * By W. HEWITT, SURGEON. * * * * * * * * * * NORWICH: PRINTED FOR THE AUTHOR, BY MATCHETT, STEVENSON, AND MATCHETT, MARKET-PLACE. SOLD ALSO BY EDWARDS AND HUGHES, 12, AVE-MARIA-LANE, LONDON. 1844. DEDICATION. _To the Right Honourable the Lords Commissioners of the Admiralty_. MY LORDS AND GENTLEMEN, A communication with your Lordships in 1843, led me to infer that an Essay upon the interesting subject connected with the present inquiry, would be received with a degree of attention according to its merits, and the importance of the object connected with it. But should you, in your superior wisdom, perceive sufficient evidence has not been advanced to render it deserving the consideration requisite at your hands, future proofs may arise upon the foundation contained in the following pages.âOn the contrary, should it meet with your approbation, the high and honourable position you maintain for the benefit of maritime affairs will, I trust, induce you to exercise your influence towards effecting a trial of the plan submitted, for the benefit of the community at large, I and for the honour and credit of your noble establishment. I am, MY LORDS AND GENTLEMEN, Your very humble and obliged Servant, THE AUTHOR. PREFACE. Many persons may consider it a remarkable circumstance, that an individual, whose profession requires his leisure time to be devoted to the acquirement of knowledge for the comfort of man in his corporeal ailments, should find an opportunity to direct considerable attention to a subject, so very different in character, as the one now submitted to the reader. {5} The suggestions, however, of a near, respected, and venerable relative, aroused and stimulated me to make the strictest investigation, and subsequently led to the submitting a plan or design for future benefit, not only to the mariner, the merchant, the ship-owner, to those whose landed property lies contiguous to the ocean, but what is of still greater consequence, the preservation of human life; and although an abler and a more experienced individual might have given a better statement, or submitted a better design, yet it is hoped sufficient will be found in this first and hasty attempt, to excite the attention of the learned and the wealthy. An acknowledgment of the truth, a grateful feeling for the assistance derived for the most important particulars on this interesting subject, induces me to introduce the name, with the exertions of my venerable relative to the notice of my readers. The Rev. John Hewitt, B.A., Perpetual Curate of Walcot, in this county, Vicar of Grantchester, and formerly a Fellow of Corpus Christi College, Cambridge, after several years of often repeated attention to the subject embraced in this Essay, expended in the year A.D. 1802 upwards of one hundred pounds in an attempt to fill up, at his own expence, the worst breach existing between Waxham and Horsey, and the design to carry it into effect appeared so feasible, that to lessen the expence, the Hon. Harbord Harbord, the first Lord Suffield, lent implements to aid the undertaking. But unfortunately, prior to the task being completed, a strong north-west wind, upon a spring tide, ensued, and a quantity of water passed through the breach partially repaired. A cottager residing near the place, witnessed the circumstance only just previous to the irruption of the water, and informed my relative had he possessed a shovel, he could have prevented it. The circumstance attending this catastrophe caused in little minds derision and contempt, from the failure of the experiment. But a humble individual, whose ideas were more enlarged, contended upwards of three hundred pounds worth of good had been effected; and the spot on that part of the coast is recognized to this day as Hewittâs Bank. While some persons, therefore, considered it a direct failure, my relative deemed it a partial one, and watched with undiminished ardour the effect produced by the stranding of the Hunter cutter, A.D. 1807; the particulars of which are fully entered into in the following pages. A knowledge of the tides and currents has been principally acquired from the perusal of several works of the most renowned philosophers, whose erudition have stamped them with truth stable and incontrovertible. I have, therefore, adopted their language rather than my own, fearful I should mar their intent, and my regard for such comprehensive writings induces me to add the truism transmitted to us by an ancient Latin authorâ Unius Ã¦tatis sunt quÃ¦ fortiter fiunt, quÃ¦ Vero pro utilitate scribuntur Ã¦terna. _Vegetius_. Should the design be put in execution, and found efficacious, it will be applicable to other coasts, by taking every particular respecting them into consideration, and great will be the reward on the ambition attained of having endeavoured to benefit the community at large. THE AUTHOR. CHAPTER I. INTRODUCTION.âTHE FORMATION OF THE TIDES CONSIDERED, THEIR VARIATION, AND EFFECTS. For, lo! the sea that fleets about the land, And like a girdle clips her solid waste, Music and measure both doth understand: For his great crystal eye is always cast Up to the moon, and on her fixed fast: And as she danceth in her pallid sphere, So danceth he about the centre here. The above lines, so beautifully expressed by one of our earlier poets, introduces a subject generally understood, but the important object connected with our present inquiry cannot be maintained without a thorough knowledge of cause and effect. A minute acquaintance, therefore, with the formation of the tides and currents, their variation and effects, transmitted to us by the observations, experiments, and discoveries of the earlier, and confirmed by the researches of the modern philosophers, will not be deemed altogether superfluous, as they will tend to remove any obstacle that might otherwise present itself on the consideration of so difficult a subject. By the term tide is meant that regular motion of the sea, according to which it ebbs and flows twice in the twenty-four hours. After some wild conjectures of the earliest philosophers, observes Goldsmith, it became well known in the time of Pliny that the tides were entirely under the influence in a small degree of the sun, but in a much greater of the moon. It was found that there was a flux and reflux of the sea in the space of twelve hours and fifty minutes, which is exactly the time of a lunar day. It was observed that whenever the moon was in the meridian, or in other words, as nearly as possible over any part of the sea, that the sea flowed to that part, and made a tide there; on the contrary, it was found that when the moon left the meridian, the sea began to flow back again from whence it came, and there might be said to ebb. Thus far the waters of the sea seemed very regularly to attend the motions of the moon. But as it appeared, likewise, that when the moon was in the opposite meridian, as far off on the other side of the globe, that there was a tide on this side also, so that the moon produced two tides, one by her greatest approach to us, and another by her greatest distance from us; in other words, the moon, in once going round the earth, produced two tides, always at the same time; one, on the part of the globe directly under her; and the other, on the part of the globe directly opposite. Kepler was the first who conjectured that attraction was the principal cause; asserting, that the sphere of the moonâs operation extended to the earth, and drew up its waters. But what Kepler only hinted, has been completely developed and demonstrated by Sir Isaac Newton. After his great discovery of the law of gravitation, he found it an easy matter to account for the whole phenomena of the tides. The moon, like all the rest of the planets, has been found to attract and to be attracted by the earth. This attraction prevails throughout our whole planetary system; the more matter there is contained in any body, the more it attracts, and its influence decreases in proportion as the distance, when squared, increases. This being premised, let us see what must ensue upon supposing the moon in the meridian of any tract of the sea. The surface of the water immediately under the moon, is nearer the moon than any part of the globe is, and, therefore, must be more subject to its attraction than the waters anywhere else. The waters will there be attracted by the moon, and rise in a heap, whose eminence will be the highest where the attraction is greatest. In order to form this eminence, it is obvious that its surface, as well as the depths, will be agitated, and that wherever the water runs from one part, succeeding waters must run to fill up the space it has left. Thus the waters of the sea, running from all parts to attend the motion of the moon, produce the flowing of the tide; and it is high tide at that part wherever the moon comes over it, or to its meridian. {11} But when the moon travels onward, and ceases to point over the place where the waters were just risen, the cause of their rising ceasing to operate, they will flow back by their natural gravity into the lower parts from whence they had travelled; and this retiring of the waters will form the ebbing of the sea. {12a} Thus the first part of the demonstration is obvious, since in general it requires no great sagacity to conceive that the waters nearest the moon are most attracted or raised highest by the moon. But the other part of the demonstration, namely, how there come to be high tides at the same time on the other side of the globe is not so easy to conceive. To comprehend this, it must be observed, that the part of the earth and its waters farthest from the moon, are the parts of all others that are least attracted by the moon; it must also be observed, that all the waters, when the moon is on the opposite side of the earth, must be attracted in the same direction that the earth itself attracts them; that is apparently quite through the body of the earth, towards the moon itself. This, therefore, being conceived, it is plain that those waters which are farthest from the moon will have less weight than those of any other part on the same side of the globe, because the moonâs attraction, which conspires with the earthâs attraction, is there least. Now, therefore, the waters farthest from the moon having less weight, and being lightest, will be pressed on all sides by those that having more attraction are heavier, and the heavier waters flowing in, will make them swell and rise in an eminence directly opposite to that on the other side of the globe, caused by the more immediate influence of the moon. {12b} In this manner the moon, in one diurnal revolution, produces two tides; one raised immediately under the sphere of its influence, and the other directly opposite to it. As the moon travels, this vast body of waters rears upward, as if to watch its motions, and pursues the same constant rotation. However, in this great work of raising the tides, the sun has no small share, it produces its own tide constantly every day, just as the moon does, but in a much less degree, because the sun is at an immensely greater distance. Thus there are solar tides and lunar tidesâwhen the forces of these two great luminaries concur, which they always do when they are either in the same or in the opposite parts of the heavens, they jointly produce a much greater tide, than when they are so situated in the heavens as each to make peculiar tides of their own; in the former, the attraction of the sun conspires with the attraction of the moon, by which means the high spring tides are formed; in the latter, the action of the sun is opposed to that of the moon, consequently the effect must be to depress the waters where the moonâs action has a tendency to raise them, and hence the production of the lower neap tides. {13a} The spring tides {13b} do not take place on the very day of the new and full moon, nor the neap tides on the very day of the quadratures, but a day or two after; the effect is neither greatest nor least when the immediate influence of the cause is greatest or least: as the greatest heat, for example, is not on the solstitial day, when the immediate action of the sun is greatest, but some time after it.âAnd although the action of the sun and moon were to cease, yet the ocean would continue to ebb and flow for some time, as its waves continue in violent motion for some time after a storm. {14a} Sir Isaac Newton has shown that the tides increase as the cube of the distances decrease, so that the moon, at half her present distance, would produce a tide eight times greater. Now the moon describes an ellipse about the earth, and of course must be once in every revolution nearer the earth than in any other part of her orbit; consequently she must produce a much higher tide when in this point of her orbit than in the opposite point. {14b} This is the reason that two great spring tides never take place immediately after each other; for if the moon be at her least distance at the time of new moon, she must be at her greatest distance at the time of full moon, having performed half a revolution in the intervening time; and, therefore, the spring tide at the full will be much less than at the preceding change. For the same reason, if a great spring tide happens at the time of full moon, the tide at the following change will be less. {14c} The spring tides are highest and the neap tides lowest about the beginning of the year; for the earth being nearest the sun about the first of January, must be more strongly attracted by that body than at any other time of the year: hence the spring tides which happen about that time, will be greater than at any other time, and should the moon be new or full in that part of her orbit, which is nearest to the earth at the same time, the tides will be considerably higher than at any other time of the year. The tide which happens at any time while the moon is above the horizon, is called the superior tide, and when below the horizon, the inferior. When the moon is in the equinoctial, the superior and inferior tides are of the same height, but when the moon declines towards the elevated pole, the superior tide is higher than the inferior. If the latitude of the place and the declination of the moon are of contrary names, the inferior tides will be the highest. But the highest tide at any particular place is when the moonâs declination is equal to the latitude of the place, and of the same name, and the height of the tide diminishes as the differences between the latitude and declination increases, therefore the nearer any place is to that parallel whose latitude is equal to the moonâs declination and of the same name, the higher will be the tide at that place. In comparing the height of tides at different places, it is supposed that the sun and moon are at the same distances from the earth, and in the same position with respect to the meridian of these places. {15a} The above observations relative to the regularity of the tides could only result by supposing the earth to be covered with the waters of the ocean to a great depth, but as this is not the case, it is only at places situated on the shores of large oceans where such tides exist. {15b} From local circumstances the tides are subject to great irregularities, such as meeting with islands, headlands, passing through straits, &c. In order that they may have their full motion, the ocean in which they are produced ought to extend 90Â° from east to west, because that is the distance between the greatest elevation and the greatest depression produced in the waters by the moon. Hence it is that the tides in the Pacific Ocean exceed those of the Atlantic, and that they are less in that part of the Atlantic which is within the torrid zone between Africa and America, than on the temperate zones on either side of it where the ocean is much broader. {16a} Tides are not perceptible in lakes and most inland seas, and deep and extensive as is the Mediterranean, are scarcely sensible to ordinary observation, their effects being quite subordinate to the winds and currents. In some places, however, as in the Straits of Messina, there is an ebb and flow to the amount of two feet and upwards; at Naples and at the Euripus, of twelve and thirteen inches, and Rennell informs us, at Venice, of five feet. {16b} The ebb and flow of the ocean is very slight in islands remote from any continent, as for example, at St. Helena, where it seldom exceeds three feet. Tides are remarkably high on the coasts of Malay, in the Straits of Sunda, on the open coast of Patagonia, along the coasts of China and Japan, at Panama, in the Gulph of Bengal, and at the mouth of the Indus, where the water rises thirty feet in height. Tides are greatest in any given line of coast, in narrow bays and estuaries; and are least in the intervening tracts where the land is prominent. {16c} On the authority of the late Captain Hewett, R.N., at the entrance of the estuary of the Thames, the rise of the spring tides is eighteen feet; but when we follow our eastern coast from thence northward; towards Lowestoft and Yarmouth, we find a gradual diminution, until at the place last mentioned the highest rise is only seven or eight feet. From this point there begins again to be an increase, so that at Cromer, where the coast again retires towards the west, the rise is sixteen feet; and towards the extremity of the gulph called âthe Wash,â as at Lynn and in Boston Deeps, it is from twenty-two to twenty-four, and in some extraordinary cases, twenty-six feet. From thence again there is a decrease towards the north; the elevation at the Spurn Point being from nineteen to twenty feet, and at Flamborough Head, on the Yorkshire coast, from fourteen to sixteen feet. It is also recorded, on the authority of Captain Beaufort, R.N., that at Milford Haven, in Pembrokeshire, at the mouth of the Bristol Channel, the tides rise thirty-six feet, and at King-road, near Bristol, forty-two feet. At Chepstow, on the Wye, a small river which opens into the estuary of the Severn, they reach fifty feet, sometimes sixty-nine, and even seventy-two feet. {17} The tides at Tonquin are the most remarkable in the world. In this part there is but one tide and one ebb every twenty-four hours; whereas in other places there are two. Besides twice in each month there is no tide at all, when the moon is near the equinoctial, the water being for some time quite stagnant. These, with other peculiar appearances attending the same phenomena, were considered by many as inscrutable; but Sir Isaac Newton adjudged them to arise from the concurrence of two tides, one from the South Sea, and the other from the Indian Ocean. Of each of these tides there come successively two every day; two at one time greater, and two at another that are less. The time between the arrival of the two greater is considered by him as high tide; the time between the two lesser as ebb. In short, with this clue that great mathematician solved every appearance, and so established his theory as to silence every opposer. This fluctuation of the sea from the tides, observes the same author, produces another and more constant rotation of its waters from the east to the west, in this respect following the course of the moon. This may be considered as one great and general current of the waters of the sea; and although it be not every where distinguishable, it is nevertheless every where existent, except when opposed by some particular current or eddy produced by partial and local causes. This tendency of the sea towards the west is plainly perceivable in all the great straits of the ocean; as for instance, in those of Magellan, in South America, where the tide running in from the east nearly twenty feet high, and continues flowing six hours, whereas the ebb continues but two hours, and the current is directed to the west. This proves that the flux is not equal to the reflux, and that from both results a motion of the sea westward, which is more powerful during the time of the flux than the reflux. This motion westward has been sensibly observed by navigators in their passage back from India to Madagascar, and so on to Africa. In the great Pacific, also, it is very perceivable; but the places where it is most obvious are, as it was said, in those straits which join one ocean to another. In the straits between the Maldivia Islands, in the gulph of Mexico, between Cuba and Jucatan. In the straits in the gulph of Paria, the motion is so violent, that it has received the appellation of the Dragonâs Mouth. Northward, in the sea of Canada, in Waigatâs straits, in the straits of Java, and in short, where the ocean on one part pours into the ocean on the other. In this manner is the sea carried with an unceasing circulation round the globe, and at the same time that its waters are pushed backward and forward with the tide; they have thus a progressive current to the west, which, though less observable, is not the less real. {19} CHAPTER II. THE ORIGIN OF CURRENTS THEIR VARIATION, EFFECTS, AND VELOCITY CONSIDERED. ANOTHER impulse communicated to the waters of the ocean arises from its currents. These are caused by the winds blowing for many months in one direction, which produce on an expansive ocean movements of considerable magnitude: this may be easily conceived when we observe the effects produced on our own seas by the temporary action of the same cause. A strong south-west or north-west wind invariably raises the tides to an unusual height along the east coast of England and the Channel. Smeaton ascertained by experiment that in a canal four miles in length, the water was kept up four inches higher at one end than at the other, merely by the action of wind along the canal; and Rennell informs us that a large piece of water, ten miles broad, and generally only three feet deep, has by a strong wind had its waters driven to one side, and sustained so as to become six feet deep, while the windward side was laid dry. He also observes, âAs water, when pent up so that it cannot escape, acquires a higher level, so, in a place where it can escape, the same operation produces a current, and this current will extend to a greater or less distance according to the force by which it is produced.â Currents flowing alternately in opposite directions are also occasioned by the rise and fall of the tides. The effect of this cause is, as before observed, in estuaries and channels between islands. Evaporation by solar heat is another cause of oceanic currents, of which the great current setting through the Straits of Gibraltar into the Mediterranean, is a remarkable example. A stream of colder water always flows from the Black Sea into the Mediterranean. It must happen in many other parts of the world that large quantities of water, raised from one tract of the ocean by solar heat, are carried to some other, where the vapour is condensed, and falls in the shape of rain, and this, in flowing back again to restore equilibrium, will cause sensible currents. There is still another way in which heat and cold must occasion great movements in the ocean; a cause to which, perhaps, currents are principally due. It is now ascertained that there is in sea water no point, as in fresh water, at which an increase of cold causes the fluid to begin again to expand. In the ocean, therefore, whenever the temperature of the surface is lowered, condensation takes place, and the superficial water having its specific gravity increased, falls to the bottom, upon which lighter water rises immediately, and occupies its place. When this circulation of ascending and descending currents has gone on for a certain time in high latitudes; the inferior parts of the sea are made to consist of colder or heavier fluid than the corresponding depths of the ocean between the tropics. If there be a free communication, if no chain of submarine mountains divide the polar from the equatorial basins, a horizontal movement will arise by the flowing of colder water from the poles to the equator, and there will then be a reflux of warmer superficial water from the equator to the poles. A well-known experiment has been adduced to elucidate this mode of action in explanation of the âtrade winds.â If a long trough, divided in the middle by a sluice or partition, have one end filled with water, and the other with quick silver, both fluids will remain quiet so long as they are divided, but when the sluice is drawn up, the heavier fluid will rush along the bottom of the trough, while the lighter, from being displaced, will rise, and flowing in an opposite direction, spread itself at the top. The expansion and contraction of sea water by heat and cold, have in a similar manner, a tendency to set under currents in motion from the poles to the equator, and to cause counter currents at the surface, which are impelled contrary to that of prevailing-trade winds. The geographical and other circumstances being very complicated, we cannot expect to trace separately the movements due to each cause, but must be prepared for many anomalies, especially as the bed of the ocean must often modify and interfere with the course of the inferior currents, as much as the position and form of continents and islands alter the direction of those on the surface. Thus, on sounding at great depths in the Mediterranean, Captains Berard and DâUrville have found that the cold does not increase in a high ratio, as in the tropical regions of the ocean, the thermometer remaining fixed at about 55Â° F. between the depths of 1000 and 6000 feet; and Captain Smith has shown in his survey, that the deepest part in the Straits of Gibraltar is only 1320 feet, so that a submarine barrier exists there, which must prevent the influx of any under current of the ocean cooled by the polar ice. The rotation of the earth on its axis is another cause which can only come into play when the waters have been already set in motion by some one or all of the forces above described, and when the direction of the current so raised happens to be from south to north, or from north to south, the principle on which this operates has been long recognized in the case of trade winds; thus, when a current flows from the Cape of Good Hope towards the Gulph of Guinea, it consists of a mass of water, which, on doubling the Cape, in latitude 35Â°, has a rotatory velocity of about 800 miles an hour; but when it reaches the line, it arrives at a parallel where the surface of the earth is whirled round at the rate of 1000 miles an hour, or about 200 miles faster. If this great mass of water was transferred suddenly from the higher to the lower latitude, the deficiency of its rotatory motion, relatively to the land and water with which it would come into juxta position, would be such as to cause an apparent motion of the most rapid kind (of no less than 200 miles an hour) from east to west. {23} In the case of such a sudden transfer, the eastern coast of America being carried round in an opposite direction, might strike against a large body of water with tremendous violence, and a considerable part of the continent might be submerged. This disturbance does not occur, because the water of the stream, as it advances gradually into new zones of the sea, acquires by friction an accelerated velocity. Yet as this motion is not imparted instantaneously, the fluid is unable to keep up with the full speed of the new surface over which it is successively brought; and Herschel, in his Treatise on Astronomy, observes, when speaking of the trade winds, it lags or hangs back in a direction opposite to the earthâs rotation, that is from east to west; {24a} and thus a current which would have run simply towards the north but for the rotation, may acquire a relative direction towards the west, or become a south-easterly current. {24b} The most extensive and best determined system of currents is that which has its source in the Indian Ocean, under the influence of the trade winds; and which, after doubling the Cape of Good Hope, inclines to the northward, along the western coast of Africa; then crosses the Atlantic near the Equator, and is lost in the Caribbean Sea; yet seems to be again revived in the current which issues from the Gulph of Mexico, by the Straits of Bahama, and flows rapidly in a north-easterly direction, by the bank of Newfoundland, towards the Azores. Rennell informs us, that the Lagullas current, so called from the cape and bank of that name, is formed by the junction of two streams flowing from the Indian Ocean, the one from the channel of Mozambique, down the south-east coast of Africa, the other from the ocean at large.âThe collective stream is from ninety to one hundred miles in breadth, and runs at the rate of from two and a half to more than four miles per hour. It is at length turned westward by the Lagullas bank, which rises from a sea of great depth, to within one hundred fathoms of the surface. It must therefore be inferred, says Rennell, that the current here is more than one hundred fathoms deep, otherwise the main body of it would pass across the bank, instead of being deflected eastward, so as to flow round the Cape of Good Hope. From this Cape it flows northward, along the western coast of Africa, taking the name of the South Atlantic current. It then enters the Bight or Bay of Benin, and is turned westward, partly by the form of the coast there, and partly, perhaps, by the Guinea current, which runs from the north into the same great bay. From the centre of this bay proceeds the Equatorial current, holding a westerly direction towards the Atlantic, which it traverses from the coast of Guinea to that of Brazil, flowing afterwards by the shores of Guiana to the West Indies. The breadth of this current varies from one hundred and sixty to four hundred and fifty geographical miles, and its velocity is from twenty five to seventy nine miles per day, the mean rate being about thirty miles. The length of its whole course is about four thousand miles. As it skirts the coast of Guiana, it is increased by the influx of the waters of the Amazon and Orinoco, and by their junction acquires accelerated velocity. After passing the island of Trinadad, it expands, and is almost lost in the Caribbean Sea; but there appears to be a general movement of that sea towards the Mexican Gulph, which discharges the most powerful of all currents through the Straits of Florida, where the waters run in the northern part with a velocity of five miles an hour, having a breadth of from thirty five to fifty miles. {25} The temperature of the Gulph of Mexico is 86Â° in summer, or 6Â° higher than that of the ocean in the same parallel (25Â° N. lat.) and a large proportion of this warmth is retained, even where the stream reaches the 43Â° N. lat. After issuing from the Straits of Florida, the current runs in a northerly direction to Cape Hatteras, in North Carolina, about 35Â° N. lat. where it is more than seventy miles broad, and still moves at the same rate of seventy five miles per day. In about 40Â° N. lat. it is turned more towards the Atlantic by the extensive banks of Nantucket and St. George, which are from two hundred to three hundred feet beneath the surface of the sea; a clear proof that the current exceeds that depth. On arriving near the Azores, the stream widens and overflows, as it were forming a large expanse of warm water in the centre of the north Atlantic, over a space of two or three hundred miles from north to south, and having a temperature of from 8Â° to 10Â° Fahr. above the surrounding ocean. The whole area covered by the gulph water is estimated by Rennell at two thousand miles in length, and at a mean, three hundred and fifty miles in breadth, an area more extensive than that of the Mediterranean. The warm water has been sometimes known to reach the Bay of Biscay, still retaining five degrees of temperature above that of the adjoining ocean; and a branch of the gulf current drifts fruits, plants, and wood, the produce of America and the West Indies, to the shores of Ireland and the Hebrides. {26} From the above statements, observes Mr. Lyell, we may understand why Rennell has characterised some of the principal currents as oceanic rivers, which he describes as being from fifty to two hundred and fifty miles in breadth, and having a rapidity exceeding that of the largest navigable rivers of the continent, and so deep as to be sometimes obstructed and occasionally turned aside by banks, the tops of which do not rise within forty, fifty, or even one hundred fathoms of the surface of the sea. The ordinary velocity of the principal currents of the ocean is from one to three miles per hour; but when the boundary lands converge, large bodies of water are driven gradually into a narrow space, and then, wanting lateral room, are compelled to raise their level. Whenever this occurs, their velocity is much increased. The current which runs through the Race of Alderney, between the island of that name and the main land, has a velocity of about eight English miles an hour. The late Captain Hewett found that in the Pentland Firth the stream, in ordinary spring tides, runs ten miles and a half an hour, and about thirteen miles during violent storms. The greatest velocity of the tidal current through the âShoots or New Passage,â in the Bristol Channel, is fourteen miles an hour; and Captain King observed, in his recent survey of the Straits of Magellan, that the tide ran at the same rate through the âFirst Narrows,â and about eight geographical miles an hour in other parts of those straits. The course of currents on the British shores is ascertained to be as winding as that of ordinary rivers. Sometimes they run between banks of sand, which consist of matter thrown down at certain points where the velocity of the stream has been retarded, but it very frequently occurs, that as in a river one bank is made of low alluvial gravel, while the other is composed of some hardy and lofty rocks constantly undermined, so the current in its bends strikes here and there upon a coast which then forms one bank, whilst a shoal under water forms the other. If the coast be formed of solid materials, it yields slowly; so also if it be of great height, for in that case a large quantity of matter must be removed before the sea can penetrate to any distance. Currents depend, like tides, on no temporary or accidental circumstances, but on the laws which preside over the motions of the heavenly bodies. The height to which tides rise, and the violence and velocity of the currents, depend in a great measure on the actual configuration of the land, the contour of a long line of continental or insular coast, the depth and breadth of channels, the peculiar form at the bottom of the seasâin a word, on a combination of circumstances which are made to vary continually by many igneous and aqueous causes, and among the rest, by the tides and currents themselves. Although these agents of decay and reproduction are local in reference to periods of short duration, such as those which history embraces, they are nevertheless universal, if we extend our views to a sufficient lapse of ages. {28} Currents, observes Goldsmith, act their part in a smaller sphere, being generally greatest where the motions of the sea are least, namely, nearest the shores, and with the tides, produce the most rapid changes; their motion agitates the substances of which their bed is composed, and at the bottom of the sea, the greatest wonders are performed, for while the sea has been known to recede from some lands, so it has been found to encroach upon others, and probably these depredations on one part of the shore may account for the dereliction of another, for the current which rested upon some certain bank, having got an egress in some other place, it no longer presses upon its former bed, but pours all its stream into the new entrance, so that every inundation of the sea may be attended with some correspondent dereliction of another shore, where the sea meets no obstacles, it spreads with a gentle intumescence, till all the power is destroyed by wanting depth to aid the motion, but when the progress is checked in the midst by the prominence of rocks or the abrupt elevation of land, it dashes with all its force its depth against the obstacle, and forms, by its repeated violence, that abruptness of the shore which confines its impetuosity. Where the sea is extremely deep, and very much vexed with tempests, it is no small obstacle that can confine its rage; and for this reason, we see the boldest shores projected against the deepest waters, all less impediments having long before been surmounted and washed away. In places where the force of the sea is less violent, or its tides less rapid, the shores are generally seen to descend with a more gradual declivity. Upon these shores the sea seldom beats with any great violence, as a large wave has not depth sufficient to float it onwards, so that here only are to be seen gentle surges making towards the land, and lessening as they approach. As the sea, in the former description, is generally seen to present prospects of tumult and uproar, here it more usually exhibits a repose and tranquil beauty. Its waters which, when surveyed from the precipice, afforded a muddy greenish hue, arising from their depth and position to the eye, {29} when regarded from a shelving shore, were the colour of the sky, and seem rising to meet it. The deafening noise of the deep sea is here converted into gentle murmurs; instead of the waters dashing against the face of the rock, it advances and recedes, still going forward but with just force enough to push its weeds and shells, by insensible approaches, to the shore. CHAPTER III. THE GERMAN OCEANâITS GEOGRAPHICAL POSITIONâITS TIDESâDISASTROUS EFFECTS IN COMBINATION WITH GALES OF WIND FROM THE NORTH-WEST ON DIFFERENT PARTS OF THE COAST UNDER CONSIDERATIONâEXAMPLES. THE workings of Nature itself, under the control of an Allwise and Omnipotent Being, ever exhibit a restorative as well as a destructive power. Its laws and constitution being no where directly revealed to us, are only to be inferred from the inspection of particular facts, obtained from observation and experiment, the only trust-worthy guides to the knowledge of Nature. Let us inquireâfirst, the cause of the German Ocean gaining upon the Norfolk coast? secondly, whether every portion is the subject of such visitation, attended with similar results? and thirdly, whether art can arrest its progress? The German Ocean, from its being intersected with numerous shoals of sand, some of immense length and breadth, presents a greater variation in the tides and currents than probably any other ocean in the world; and from its exposure to variable and violent winds, renders the navigation extremely dangerous. Its extent in area is about two millions of square miles, and is confined within its narrowest limits between England and Holland, and there in consequence the tides rise highest. It opens into the Atlantic on the north, and communicates with the English Channel by the Straits of Dover, and with the Baltic Sea by the Scaggerac and Cattegat. It may be considered as divided into two parts by the Dogger Bank, which traverses it in almost all its width, and a strong tide runs from north to south, {32} which is much increased by north and north-west winds. From the earliest records to the present time, that portion of the coast extending from Cromer to Winterton-ness has been most subjected to the ravages of the ocean; lands have been swept away, buildings of considerable value have been swallowed up, and notwithstanding every effort hitherto made, the sea continues to advance in the interior as little satiated as before. The line of coast is extremely favourable to its rapacity, presenting, as it does, the appearance of a cape, and the different strata composing the cliffs are generally of too yielding a nature to resist its influence, even under ordinary circumstances.âThe Hasborough Sands, extending from Winterton, to or a little beyond Bacton, must, from their dimensions and abrupt elevation, be a source of considerable mischief, confining a vast body of water within a narrow limit, which, when increased and disturbed by gales of wind from the north-west, upon a spring tide, urges the waves against the cliffs with a greater or less velocity, and with a force not only sufficient to sweep away large quantities of the earth, which, from the perpendicularity of the cliffs, is deposited at their base, but actually to undermine them to a considerable extent. Numerous instances can be adduced where the current has taken away twenty-one yards of land from the interior in three tides; and it was computed when the present Inn was built in Lower Sherringham, near Cromer, in 1805, that it would require seventy years for the sea to reach the spot, the mean loss of land being calculated, from previous observations, to be somewhat less than one yard annually; the distance between the house and the sea was fifty yards, but no allowance was made for the slope of the ground being from the sea, in consequence of which the waste was naturally accelerated every year as the cliff grew lower, there being at each succeeding period less matter to remove when portions of equal area fell down. Between the years 1824 and 1829, no less than seventeen yards were swept away, and the distance between the house and the edge of the cliff at this time is only from eight to ten yards. The whole site of ancient Cromer {33a} now forms part of the German Ocean, the inhabitants having gradually retreated inland to the present situation, from whence the sea still threatens to dislodge them. The locality of this portion of the coast, the scarcity of sea beach material in the offing, the bed of the ocean of a rocky character, and the beach presenting nearly a level approaching a dead flat render it peculiarly liable to its invasion. At Trimingham {33b} upwards of fifty acres of land have been removed during the last sixty years, and on one occasion four acres and a half were taken away in one tide. The property belonging to Mr. Wheatley, at Mundesley, {34a} has become considerably reduced in extent and value, and has only been preserved to the present time by substantial walls erected next the sea, and numerous piles of wood driven into the sand beyond them: but what renders it most disheartening is, the sea has excavated the cliff at their extremity; and the probability is, should a heavy lasting gale of wind ensue from the north-west upon a spring tide, they, with perhaps the greater portion of the property, will be swept away by the water intruding behind and between them. Land attached to the estate of S. Bignold, Esq., adjoining Walcot {34b} Gap, previous to 1839, was rapidly taken away. At Hasborough, {34c} the sea has encroached upwards of one hundred and seventy yards during the last sixty years, and it is calculated the church will be engulphed in the Ocean before the middle of the ensuing century. The ancient villages of Shipden, {34d} Whimpwell, {34e} and Keswick {34f} have entirely disappeared, and nearly the whole of Eccles. {34g} A monument, however, still remains in the ruined tower of the old church, which is half buried in the dunes of sand. These have been fast encroached upon since 1839, laying bare the foundations of dwellings, the chancel end of the church, with a portion of a wall supposed to have surrounded the church-yard. The upper part of the buildings had evidently been removed previous to the foundations having been buried under the sand. Hills of blown sand, between Eccles and Winterton, {34h} extending to Yarmouth, have barred up and excluded the tide for many centuries from the mouths of several small estuaries; but there are records of nine breaches, from twenty to one hundred and twenty yards wide, having been made through these, by which immense damage was done to the low grounds in the interior. One of the most remarkable occurred in the year 1792, on which occasion a body of water passed through between Horsey {35a} and Waxham, {35b} extending beyond Hickling, a village situated three miles inland, which, uniting with the fresh water contained in a large lake, termed the Hickling broad, destroyed all the fish. The injury the land sustained in the immediate neighbourhood was very considerable; upon one farm a loss of upwards of three hundred pounds was experienced, and years passed by before the land recovered its former fertility. The effluvia arising from the subsidence or sinking of the water filled the air with malaria of the worst description. Intermittent and typhoid fevers of a most formidable character prevailed, so that many an individual was brought to a premature grave through this catastrophe. CHAPTER IV. REMARKS ON THE GERMAN OCEAN CONTINUED.âITS RESTORATIVE POWERS ON OTHER COASTS DEMONSTRATED.âINCREASE OF THE SHOALS OF SAND OFF HASBOROUGH, CAISTER, &C.âTHE SMALLER SHOALS OF SAND ALONG THE COASTâTHEIR FORMATION AND EFFECTS CONSIDERED. HAVING now brought together ample proofs of the destructive operations of the waves, tides, and currents upon our eastern coast, let us observe examples of their restorative power, in many instances aided and assisted by the hand of man. The German Ocean is deepest on the Norwegian side, where the soundings give one hundred and ninety fathoms; but the mean depth of the whole basin may be stated at no more than thirty-one fathoms. {36} The bed of this sea is traversed by several enormous banks: one of which, occupying a central position, trends from the Frith of Forth in a north-easterly direction, to a distance of one hundred and ten miles; others run from Denmark and Jutland, upwards of one hundred and five miles to the north-west; while the greatest of all, the Dogger Bank, extends for upwards of three hundred and fifty-four miles from north to south. {37a} The whole superficies of these
{'title': 'An Essay on the Encroachments of the German Ocean Along the Norfolk Coast by Hewitt', 'source': 'Project Gutenberg', 'lang': 'en'}