Produced by Chris Curnow, Paul Marshall and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) [Illustration: (_See Page 41._)] ELEMENTARY COLOR BY MILTON BRADLEY. Author of "Color in the Schoolroom" and "Color in the Kindergarten." WITH AN INTRODUCTION BY HENRY LEFAVOUR, Ph.D., Professor of Physics, Williams College. Third Edition. MILTON BRADLEY CO., SPRINGFIELD, MASS. COPYRIGHTED, 1895, BY MILTON BRADLEY CO., SPRINGFIELD, MASS. CONTENTS. PAGE. THE THEORY OF COLOR 9 Why Artists and Scientists Have Disagreed 10 The Speculations of the Past 12 What the Primary Teacher Needs to Consider 13 Concerning the Solar Spectrum 15 Six Spectrum Standards of Color 17 The Color Wheel and Maxwell Disks 18 The Bradley System of Color Instruction 20 COLOR DEFINITIONS 23 PRACTICAL EXPERIMENTS 31 The Color Wheel 31 The Color Top 32 Use of the Disks 32 How to Begin the Experiments 34 The Old Theories Tested by Mixture of Three Pigments 45 Old Theories Tested by the Color Wheel or Color Top 46 Concerning the Complementary Colors 50 Citrines and Russets 54 Olives 55 Vermilion, Burnt Sienna, Raw Sienna and Indian Red 55 Classification of Harmonies 56 The Work of Chevreul Reviewed 58 Simultaneous, Successive and Mixed Contrast 61 Contrasted Harmony 64 Color with White 64 Black with White 64 Color with Black 65 Colors with Gray 65 Contrast of Colors 67 Dominant Harmonies 67 Complementary Harmonies 69 Analogous Harmonies 70 Perfected Harmonies 70 Field's Chromatic Equivalents 73 Colored Papers 74 COLOR TEACHING IN THE SCHOOLROOM 76 The Glass Prism 78 How the Bradley Color Standards Were Chosen 79 Paper Color Tablets 80 Color Wheel or Top 82 The Study of Tones 85 Neutral Grays 89 Explanation of Broken Colors 91 An Exercise in Broken Colors 92 Formulas for a Chart of Broken Spectrum Scales 95 Certain Color Puzzles 96 Chart of Pure Spectrum Scales Completed 98 The Work of Cutting and Pasting 99 A Variety of Designs 101 Analysis of Color Materials 106 The Bradley Colored Papers 112 Engine Colored Papers 116 Water Colors 118 Color Blindness 121 OUTLINE OF A COURSE IN COLOR INSTRUCTION 124 The Solar Spectrum 125 Pigmentary Spectrum Colors 125 Study of Tones 126 Broken Colors 127 Complete Chart of Pure Spectrum Scales in Five Tones 127 Advanced Study of Harmonies 128 INTRODUCTION. The movement in educational reform at present is in the direction of unification. It is held that in framing the programme for any grade the interest not only of the next higher but of all higher grades must be considered. This is done not solely that those who are to enter the higher grades may be directly prepared for their more advanced studies, but especially because it is felt that better work will thus be done for those whose school training is soon to terminate. For the child's education is never finished and a mind rightly directed at the start will gather from its practical experience that with which it may develop and augment the resources and the ideas already received. No education can be sound which teaches anything that is inconsistent with the more advanced truths, however complex and profound those truths may be. There should be no unlearning in the course of an education nor any expenditure of time on that which has no permanent value. It is of importance therefore to consider in connection with the study of any special subject what the problems are which lie at the end of the educational journey and what basis will be needed in the child's maturer thought. There will thus be the inspiration of the goal to be attained and guidance in the selection of the most helpful methods. There is scarcely any subject that has so many practical and scientific aspects as the subject of color. Its great importance in the arts and its contribution to the enjoyment of life are matched by the multiplicity of problems in the physical and philosophical sciences with which it is connected. Without attempting to enumerate all of the scientific problems related to this subject, it may be of interest to briefly summarize those which are most prominent. At the outset we have such purely physical questions as the nature of light, the cause of its emission, the mode of its propagation, the difference in the waves which give rise to the various color sensations, the principles of absorption, of reflection and of refraction, and the nature of material surfaces whereby they acquire their characteristic colors. Then comes the physiology of the eye, including its structure and its function and involving the much discussed questions of primary and secondary colors, and these are closely related to the psychological or psycho-physical study of the nature, duration and delicacy of color vision and color judgment. Next to these comes the study of pigments and of the chromatic effects of their mixture, essentially a chemical and technical question, and finally, the most important of all, the purely psychological or æsthetic problem touching the harmonization and grouping of the various colors and their modifications. The recent advance made in experimental psychology has given an impetus to the study of the whole subject and we may reasonably expect that rational explanations may be found for questions in æsthetics hitherto considered purely arbitrary. It will be readily seen that there must be a well developed and carefully trained color sense at the basis of an education which is to lead to the consideration of these and similar chromatic problems. As in the development of any special perceptive power, a great deal depends upon making a beginning early in life, when the mind is most receptive and there are no preconceptions to be overcome. Every means should be employed that will help the child to distinguish between principal colors and between modifications of principal colors. His attention should be directed at as early a stage as possible to the analysis of composite colors and the effects obtained by the combination of colored lights and the results of irradiant light. The principles of chromatic harmony are perhaps not simple, but a child, before whom right standards of color combinations are constantly presented, will acquire a correct æsthetic judgment that may become intuitive. The effect of such a training on the higher development of our people and on their appreciation of true art would be of the greatest value. If the instruction in color is to be systematic and efficient, it is unquestionable that there must be a simple nomenclature for the standard colors; and for the teacher's guidance at least as well as for the use of the older pupils, a scientifically accurate system of describing any required modification of these recognized standards. The system presented in this book is based on the well-known principle of the Maxwell wheel and has been elaborated by one who has had in view not only the theory of the subject but also the practical possibilities of its use in preparing educational material. This fact, I feel sure, greatly enhances the value of the conclusions at which he arrives. HENRY LEFAVOUR. Williams College, December 20, 1894. PREFACE. Ever since Newton discovered the solar spectrum it has been referred to in a poetic way as Nature's standard of color. But as soon as the author attempted, some twelve years ago, to use it practically by making pigmentary imitations of the spectrum colors as standards they were decried as vulgar and inartistic. Under such circumstances it was a great pleasure to him to hear a celebrated art professor answer his inquiry if the solar spectrum is the proper place to look for standards of color with the emphatic assertion, "Certainly, there is no other place to go." Where there are no standards there can be no measurements, and if in color we have no measurements of effects, no records can be made, and hence no comparisons of results at various places and times, and consequently no discussion and little progress. Because there have been no accepted standards and no measurements of color very little has thus far been decided regarding psychological color effects. In drawing, as at present taught in our best schools from the kindergarten to the university, the foundation of art in black and white is laid in form study. From the drawing teachers we learn that a good touch and a fine sense for light and shade in all their subtle relations to each other are without value, unless due care has been given to the commonplace consideration of lengths and directions of lines, that is to say to the measurement of lines and angles, and to the laws of perspective. We cannot have measurements without standards. By the foot or the metre we measure lines and by the divided circle we measure angles. Geometrical forms have already been so definitely analyzed by the science of mathematics that if destroyed to-day these solids and surfaces could be reconstructed at any future time from written or printed directions. But suppose all material samples of color to be lost, it would be impossible by the ordinary system of color nomenclature to even approximately restore a single one from written or verbal descriptions. Color is one of the first things to attract the attention of the infant, almost as soon as a sound and long before form appeals to him, so that a collection of colored papers will often prove more interesting and instructive than a picture book to the baby, while the graduate from a two year's course in the kindergarten may have a better color sense than is at present enjoyed by the average business or professional man. If we could determine the colors used by the great masters in the past, we could add much to our knowledge of the fine arts; and if we knew what colors Chevreul, the master dyer of the Gobelins Tapestry works, refers to in his writings, and which he indicated by hundreds of numbered samples filed away in his cabinet, we should in this generation have a wonderful fund of information to increase our knowledge of harmonies, on which to base our study of color in the industrial arts. But alas! the paintings of the old masters have faded and the great dyer had no language in which to describe his colors in his writings, and therefore it is claimed that little or no advance in color perception has been made in modern times, if indeed we have held our own. The further assertion is made that those semi-civilized nations whose drawings are the least artistic greatly surpass us in natural color perceptions. If color is the one thing in which we are deficient and in which we are making no advance, is it not necessary that we adopt a new line of operations for our color instruction in the primary grades? It is self-evident that in primary work highest art is not expected in either literature, music, drawing or painting, but as has been the aim in literature for a long time and in drawing and music more recently, so in coloring, our instruction should be based on those principles on which highest art must rest. When through the introduction of colored papers in the kindergartens and primary schools the teachers began to call for better assortments of colors in their papers than were to be found in the market, and some of us in the field attempted to meet their wants, the solution of the problem seemed almost a hopeless task, because no two wanted the same colors; each teacher was a law to herself and one thought a color "just lovely" which another declared "perfectly horrid." According to the early theories then in vogue the first colors called for were red, yellow and blue for primaries, but no two persons were sure just what they wanted for either of these, and there was no authority to be referred to for a decision. In this strait, which was practically a serious difficulty, the artists were appealed to for a decision as to the three "primary colors," and also for examples showing in what proportions the "ideal primaries" must be mixed to produce the "ideal secondaries." But in this there was no satisfaction because hardly two agreed in the primaries and necessarily the secondaries were much less definite, which was the result that should have been expected. It is a self-evident proposition that if two indefinite primaries are combined in indefinite proportions the possible secondaries which may thus be produced must be exceedingly numerous, and if this idea is carried out in the production of tertiaries by the combination of the secondaries the resulting colors may be almost infinite. In view of the indifference of the artists and the popular ignorance regarding the subject the solution of this question and the discovery of any solid basis on which to formulate a system of elementary color instruction seemed very problematical. But after much experimenting and many conferences with artists and scientists a basis for operation was decided upon and at the end of fifteen years the efforts begun in doubt have resulted in a definite system of color instruction which it is the purpose of this book to concisely set forth. It is prepared in response to inquiries from primary school teachers for a clear and condensed explanation of the Bradley System of Color Instruction. The aim is to offer a definite scheme and suitable material for a logical presentation of the truths regarding color in nature and art to the children of the primary schools. Much of this instruction is so simple that it should be familiar to children who have had kindergarten training and has therefore already been explained in substantially the same form in "Color in the Kindergarten." A few years ago it might well have been thought necessary to preface a treatise on the subject with arguments to prove that color is a legitimate object for school instruction, but to-day this is not a question with thoughtful educators, whether considered from the practical, industrial or æsthetic standpoint. With the establishment of professorships of practical psychology and the equipment of laboratories, provided with delicate and expensive apparatus for making and recording tests, there comes with increasing force the demand for some means by which the experiments in color made in various localities may be unified both as to the colors used and the terms and measurements for recording the result. It is the hope of the author that the system here outlined may be the initial step in gathering together such facts regarding color effects as will form a fund of knowledge little dreamed of at the present day. [Illustration] The Theory of Color. In order to place the study of color on a broad and safe foundation, the work must commence at the bottom with a rational presentation of the subject, based on experiments and the use of color material. We must intelligently consider the relation that exists between the pure science of light which is the source of all color and the use of color materials with their effect on our color perceptions. While it is true in all study that there is here and there found a natural genius in some line of work who seems to have such inborn perceptions as to require little or no logical instruction in his special line, it is also manifest that the masses must gain their knowledge through a systematic presentation of the subject, if they secure it at all. Therefore with the growth of modern pedagogics the laboratory work of the psychologist has become a necessity. This consists in collecting and tabulating the results of hundreds and thousands of experiments regarding any subject under investigation, and the averaging of these to form theories and laws. In making these experiments there must be standards and measurements on which they may be based and some nomenclature in which to make the records; and the standards, measurements and nomenclature adopted must be common to those who desire to compare their results made in different places at different times. From the results of many physical experiments properly measured and recorded certain psychological theories are deduced. These experiments are tried on hundreds and thousands of individuals and the average results establish the theories, which will ultimately stand or fall according to the truth and accuracy with which the experiments have been made. Experiments are useless for formulating any exact theories unless they can be recorded in some generally accepted terms for comparison with other experiments made under similar conditions and recorded in the same terms. So in color perceptions it is not necessary that we know anything of the theories of color in order to see colors, and if endowed by nature with a natural genius for color, education in color may not be necessary, but if there is to be education in color which can be transmitted to a second party there must be some standards of colors and some measurement of color effects which can be recorded in accepted terms. Why Artists and Scientists Have Disagreed. In the realm of art there is no necessity for any purely scientific analysis of sunlight, which is the origin of natural colors, because all the practical value of color is found in its æsthetic effects on the mind, and in order to enjoy these even in the highest degree it is not necessary that we understand the scientific origin of the colors, any more than it is necessary for the artist to know the chemical composition of his pigments in order to produce best effects with them on his canvas. Because of this almost self-evident fact, artists have as a rule been very impatient when any reference has been made to the science of color in connection with color education, believing that color is an exception to the general subjects of study to such a degree that it lies outside of all scientific investigations. Consequently they have not been in sympathy with the physio-psychological investigations which have been prosecuted with such promising results in other lines, when such investigations have been proposed regarding color. While it is not essential for best results in his own work that an expert artist shall know anything of the science of color, still if he is to communicate his knowledge of art to any others except his personal pupils, he must have some language in which to make known his ideas, and on the same grounds if any psychological tests are to be made regarding color, it is evident that there must be some accepted terms in which to record the results, which has not hitherto been the case. When the well known Newton and Brewster theory of three primary colors red, yellow and blue, was advocated by those scientists there appeared to be something of interest and value in it for the artists also, because with the three pigments red, yellow and blue, they seemed to be able to confirm the truth of the scientific theories regarding the spectrum colors. But the scientists have long been convinced that there is no truth in this theory and have quite generally accepted the Young-Helmholtz idea of three other color perceptions red, green and violet, from which they claim all color vision is produced, and which they call fundamental colors. This more modern theory has seemed so far removed from the realm of the artists and the colorists that they have not been able to see anything in it of truth or value to them, and so have continued to repeat the old, old story of the three primaries red, yellow and blue, from which the secondaries orange, green and purple are made etc., etc., all of which is the more pernicious when accepted as a correct theory because of its seeming approximation to the facts. And yet there is not in it all any scientific truth on which to build a logical system of color education, and some of the effects which are considered prominent arguments for the system are directly opposed to well known facts in the science of color. Consequently, the artist has failed to gain from the investigations of the scientists anything to aid him in his pigmentary work, and the scientist has not been interested in the æsthetic ideas of the artists which in fact he has generally been unable to fully appreciate, from lack of training and associations. The system of color instruction here presented for primary grades is based on the results of careful study and experiment for many years in which the attempt has been made to bring the scientist and the artist on to common ground, where they may work in sympathy with each other instead of at cross purposes as has been the case heretofore, and the results with children have already been such as to testify fully to the efficiency of this line of work. Thus the feeling for color which every true artist has, may be to a certain extent analyzed so that it can be understood by the scientist and recorded for the benefit of fellow artists one hundred or a thousand miles away and in time an aggregation of facts regarding the psychological effects of color collected which will form the beginning of a valuable fund of color knowledge to be increased from age to age. The Speculations of the Past. Ever since Newton produced the prismatic solar spectrum, the so-called science of color as applied to pigments and coloring, has been a most curious mixture of truth, error and speculation. It was supposed by Newton and Brewster that in the solar spectrum the colors were produced by the over-lapping of three sets of colored rays red, yellow and blue. The red rays at one end were supposed to overlap or mix with the yellow rays to make the orange, and on the other side of the yellow the blue rays were supposed to combine with the yellow to produce green. Following the same theory in pigmentary colors, it has been claimed that all colors in nature may be produced by the combination of pigments in these three colors red, yellow and blue, and hence they have been called primary colors. It is still claimed by the advocates of this theory that from the three primaries red, yellow and blue the so-called secondaries orange, green and purple can be made, and that the secondaries are complementary to the primaries in pairs; the orange to the blue, the green to the red and the purple to the yellow. By similar combinations of the secondaries it is claimed that three other colors, in themselves peculiar, and different from the first six, may be made, the orange and green forming citrines, orange and violet russets, and green and violet olives and these are called tertiaries. After having accepted this fiction as a scientific theory for so many years, it is very difficult to convince the artists and colorists that in it all there is nothing of value to any one, but such is practically a fact, because from no three pigmentary effects in red, yellow and blue can the three colors orange, green and purple of corresponding purity be produced, neither are the primary colors complementary to the secondaries as claimed nor are the so-called tertiaries new and distinct colors but simply gray spectrum colors. Because the red, yellow and blue theory would not stand the test of scientific investigation the Young-Helmholtz theory of three other primaries red, green and violet, has been quite generally adopted by the scientists of the past generation. What the Primary Teacher Needs to Consider. All these discussions of the scientists are intensely interesting and no doubt of great importance in the line to which they pertain, but practically neither the artists nor the primary school teachers care for all these theories and discussions and because the scientists have closely confined themselves to these lines, the artists and teachers have seen nothing of value to them in their theories. In going to the solar spectrum for standards on which to base pigmentary standards, we have given little attention to these various theories in their details, but the one fact of science has received careful attention, namely, that all color effects in nature and art are produced by light reflected from material surfaces. Therefore, inasmuch as the light reflected from any surface must be affected by both the material color of the surface and the color of the light which illuminates the surface, it is necessary that every one having to do with this subject be informed as to what color must be expected to result from given conditions. In order that this phase of the subject be discussed and thus more fully understood, there must be a terminology or nomenclature in which to express the results produced by given conditions, and also standards by which to analyze, measure and record these results. In selecting these standards more regard must be given to the æsthetic or psychical effect of the pigmentary standards than to the purely scientific or physical properties of colored light. This selection is of great interest to the physiological psychologist because it is only by the comparison and averaging of thousands of experiments made on different people that valuable theories can be formulated. With standards and a nomenclature, color will be placed on an equal footing with other subjects, so that perceptions of color effects may be recorded and discussed with much of the definiteness with which we treat form and tone. Because this has not heretofore been possible, comparatively little advance has been made during the last two decades in the æsthetic consideration of material color _which is the only practical phase of the subject_, and if any greater progress is to be achieved in the future it evidently must be along new lines. From the nursery to the university we are constantly asking two questions, "What is it?" and "Why is it?" and this is what the educator from the Kindergarten to the College is called upon to answer. In his laboratory the psychologist is collecting physical facts by tests regarding the powers of the eye and the ear, the sense of touch, weight, memory, etc., and these experiments when classified, arranged and averaged, furnish a basis for formulating theories, all of which is called psychology. In vision, form and color play the principal parts, in fact cover the whole ground if we include light and shade in color where it belongs. Experiments regarding form can be and have long been very definitely recorded but this has not been true with color. To Froebel must be given the honor of introducing logical form study into primary education, and on this has been built the present admirable system of drawing in our higher grades of schools, and the introduction of the standard forms in solids and surfaces has brought about a definite use of geometrical terms by young children which would have seemed very unnaturally mature a generation ago. But in color no corresponding advance has been made because there have been no generally accepted standards in color to correspond to the sphere, cube, cylinder, circle, ellipse and triangle in form, nor any means for measurements to take the place of the foot or metre for lengths and the divided circle for angles. It is not expected that the children in the lowest grades will learn much of the science of color, but it is desirable that the teachers have such knowledge of it that they will not unconsciously convey to the children erroneous impressions which must be unlearned later in life. Concerning the Solar Spectrum. More than two hundred years ago Sir Isaac Newton discovered that a triangular glass prism would transform a beam of sunlight into a beautiful band of color. If the prism is held in a beam of sunlight which enters a moderately lighted room, there will appear on the walls, ceiling or floor, here and there, as the glass is moved, beautiful spots in rainbow colors. If the room is darkened by shutters, and only a small beam of light is admitted through a very narrow slit and the prism properly adjusted to receive this beam of light, a beautiful band of variegated colors may be thrown on to a white ceiling or screen, and this effect is called a prismatic solar spectrum. A perfect solar spectrum once seen under favorable conditions in a dark room is a sight never to be forgotten. The accompanying illustration shows the relative positions of the parts named. A is the beam of light as it enters the room. B is the triangular prism. The dotted lines represent groups of rays extending to the vertical band of colors indicated by the letters V for violet at the top, then blue, green, yellow, orange to red at the bottom. The explanation of this phenomenon is that the beam of sunlight is composed of a great number of different kinds of rays, which in passing through the prism are refracted or bent from their direct course, and some are bent more than others, the red least of all and the violet most. It is supposed that light is propagated by waves or undulations in an extremely rare substance termed ether which is supposed to occupy all space and transparent bodies. These waves are thought to be similar to sound waves in the air or the ripples on the smooth surface of a pond when a pebble is thrown into it. Because so many of the phenomena of light can be satisfactorily explained by this theory, it has been very generally adopted by the scientists. The amount that rays of light are refracted from a straight line in passing through a prism is in proportion to the number of waves or undulations per second, and in inverse proportion to the length of the waves. The red waves are refracted the least and are the longest, while the violet rays are refracted the most and are the shortest. [Illustration: FIG. 1.] Whether this theory of the spectrum formation is absolutely correct or not, the fact is established that the colors found in a prismatic solar spectrum are always the same under the same conditions and the order of their arrangement is never changed. By means of the quality of spectrum colors called the wave length, a given color can always be located in the spectrum, and hence if a spectrum color is selected as a standard it can always be determined by its recorded wave length. Six Spectrum Standards of Color. Therefore it seems possible to establish certain standards of color by a series of definitely located portions of the solar spectrum and in the system here presented six have been chosen, namely red, orange, yellow, green, blue and violet. These six are more distinctly recognized than the others, and from them by combination in pairs of colors adjacent in the spectrum all the other colors can be very closely imitated, and hence these six are selected as the spectrum standards. In these standards the most intense expression of each color is chosen i.e. the reddest red, greenest green, etc. which by the closest scientific investigation have been located by their wave lengths so that if they are in doubt in future they can be re-determined by individuals or if disputed, may be corrected by any authoritatively established congress, selected for the purpose. The wave lengths of our six standards are represented by the following numbers in ten millionths of a millimeter. Red, 6571; Orange, 6085; Yellow, 5793; Green, 5164; Blue, 4695; violet, 4210. Having thus scientifically established these unchangeable standards the attempt is made to secure the best possible pigmentary imitation of each. To any one who has ever compared a piece of colored material with a good presentation of a spectrum color, it is unnecessary to say that the result in an attempt to match the spectrum color with the material or pigmentary color is a very weak approximation, but the one thing aimed at is to secure nearly as possible the same kind of color. For example in the red, it is the aim to obtain the same _kind_ of red, by which we mean the same location in the spectrum, i.e. a red neither more orange nor more violet than the reddest spot in the spectrum. This selection must be based on a purely æsthetic perception or impression of color. The same is true of each of the six standard colors, as for example, for orange we select the location which has seemed to a large number of good judges to best represent the feeling of orange as between the quite well defined red on one hand and the equally definite narrow band of yellow on the other, and it is quite wonderful what unanimity of opinion there is on this particular color which would naturally seem to be the one most doubtful in its location. On the other side of the yellow the green seems to offer little difficulty and the pure Paris or emerald green is very nearly the standard. The violet being at the other end of the spectrum is as easily decided as the red, but the blue between the green and violet is not so easily determined, because, from the best blue the hue runs so imperceptibly into the violet on one side and the green on the other. Pure ultramarine blue is the nearest approach to the spectrum standard of blue of any of the permanent pigments, but even this is a trifle too violet. For educational purposes papers coated with pigments afford at once the purest colors and the most economical and useful material, and on this plan a line of colored papers has been prepared for color instruction in the kindergartens and primary schools in imitation of the above described spectrum standards. From the pure spectrum standards it is possible by reflected light to combine the two standards to produce a color between them, for example if two small mirrors are held in a spectrum one at the "red" and the other at the "orange" and the two reflected on to the same spot on a white surface, the result is a color between the red and the orange. So also if we mix red and orange pigments together we may produce colors between the two which may be termed orange-red or red-orange; but unfortunately there is no means known by which we can measure the proportion of the red and orange color-effect which is produced by any given mixture of these two pigments, because color-effect cannot be measured by the pint of mixed paint or the ounce of dry pigment. The Color Wheel and Maxwell Disks. We, however, have another means for measuring color effect which just in this emergency seems providential. It is a fact well known to every boy that if he rapidly whirls a lighted stick the fire at the end produces the effect of a circle of light, which phenomenon is explained by a quality of the eye called retention of vision, by which the impression made by the point of light remains on the retina of the eye during an entire rotation. It is a fact, based on the same quality of vision, that if one color is presented to the eye, and instantly replaced by another the effect is a combination of the two colors. Therefore if one-quarter of the surface of a disk of cardboard is covered with orange paper and three-quarters with red paper, and then the disk placed on a rapidly rotating spindle, the color effect is a mixture of red and orange, and the effect is exactly in proportion to the angular measurements of the two sectors, so that if the circumference is divided into 100 equal parts the resultant color will be definitely represented by the formula "Red, 75; Orange, 25." Less than forty years ago an English scientist named J. Clerk Maxwell while making experiments with such painted disks happily conceived the idea of cutting a radial slit in each of two disks from the circumference to the center so that by joining the disks they could be made to show any desired proportion of each and hence they are called Maxwell disks. With such disks made in the six pigmentary standards red, orange, yellow, green, blue and violet, the intermediate pigmentary spectrum colors may be very accurately determined by combination and rotation. If we give to each of these standards a symbol as R. for red, O. for orange, Y. for yellow, G. for green, B. for blue, V. for violet, we then have the basis for a definite nomenclature of colors in imitation of the pure spectrum colors. As all pigmentary or material colors are modified by light and shade thus producing in high light tints and in shadow shades of the colors, we must seek for some means of imitating these effects, and fortunately find them in white and black disks. If with a standard color disk we combine a white disk we may have a line of tints of that color, and with a black disk, shades. Giving this white disk a symbol of W. and the black disk N. we complete our nomenclature. We cannot use B for black because B has already been used for blue, and therefore we use N. for _niger_, the Latin word for black. The Bradley System of Color Instruction. Briefly stated then this system of color instruction is comprised under the six general heads: Spectrum Standards; Pigmentary Standards based on the spectrum standards; Maxwell Rotating Disks in the pigmentary standards and Black and White; a Color Nomenclature based on the accepted standards and their disk combinations; and Colored Papers and Water Colors made in accordance with these standards. For spectrum standards, six definite locations expressing the natural æsthetic or psychological impressions of red, orange, yellow, green, blue and violet are selected. Six standards are chosen instead of a larger number as for example twelve, because for the purpose of a nomenclature the smaller number is more convenient than a greater number. The six are selected rather than three, four or five, because while in the consideration of colored light alone the smaller number would possibly suffice to form by combinations imitations of all other colors, any number smaller than six is entirely inadequate to form by pigmentary or disk combinations fairly good expressions of the corresponding spectrum color combinations. In selecting the spectrum standards special prominence has been given to the psychological color perceptions of experts in determining those locations in the spectrum best expressing the color feeling of red, orange, yellow, green, blue and violet, while the purely scientific consideration of these several questions has not been ignored or lightly treated. For pigmentary standards the best possible pigmentary imitations of the six spectrum standards are secured and to these are added the nearest approach to white and black that can be produced in pigments. Pigmentary standards on which to base a nomenclature are valueless without some means by which measurements of standards embraced in a given compound color can be expressed. The Maxwell color disks are the only known means by which we may measure the relative proportions of color effect embodied in a given color, and therefore the eight color disks are the foundation of the original color nomenclature herein advocated. Colored papers are chosen for primary color instruction because paper is a valuable medium for simple schoolroom manual training and because no other pigmentary medium is at once so economical and affords such pure colors as may be secured in specially prepared colored papers, without a glazed surface. Before leaving this part of the subject we do well to remember that in the present conditions of chemistry as applied to the preparation of pigments it is not possible to establish any absolutely definite science of such color combinations. Nor is it possible to establish permanent pigmentary standards without great expense, but if the locations of the standard colors in the spectrum are established by wave lengths the pigmentary standards may be re-determined at any time and produced, in the purest pigments available at the time. In art or harmony effects, the purity of the pigmentary standard is not so important as its hue, i.e. its location in the spectrum, which may always be determined by the established wave length. This last statement may be illustrated by the investigations regarding complementary harmonies. Scientifically one color is not considered complementary to another unless when combined in equal quantities they produce white light, or in other words when combined by the rotation of disks each color must occupy a half circle and the result must be a neutral gray. But this is not essential in considering a complementary harmony, as harmonies in different tones and in various proportions are pleasing and as yet the proportions and tones which produce the best combinations have not been determined. The entire question of harmonies or pleasing color effects is dependent on individual color perception, and the establishment of rules and laws on these points can result only from a comparison of the opinions of many experts in various localities and at different times. This cannot occur without some means for recording these opinions in generally accepted terms. It is too late for any individual opinion to be accepted as authority regarding the relative values of two different harmonies in color and this will be still less possible as we become better educated in color and able to sense finer distinctions in color combinations. [Illustration] Color Definitions. Among other advantages to be gained by a logical study of the psychology of color is the establishment of more accurate color terms and definitions. If experiments and discussions based on accepted standards and methods of comparisons can be carried on we may hope in time to have as definite expressions of color terms as we now have in music and literature. All color terms used by artists, naturalists, manufacturers, tradesmen, milliners and the members of our households are as indefinite as one might naturally expect from the utter lack of a logical basis for the whole subject. Without definitions or means for intelligently naming any color, it is not strange that the terms used in speaking of colors and color effects are so contradictory as to lose much of their force, if perchance they retain anything of their original meaning. For example, probably most people apply the term SHADE to any modification of a color, either a hue, tint or shade. It is true that a concise and reasonably full dictionary of color terms must be the outcome of long experience in the logical study of the science of color and its use in our every-day lives, and at the best only suggestions can be made at present. But as there must be a beginning and some terms seem to be fairly well established, the following incomplete list of definitions is offered, always subject to amendment by the majority vote, for whenever such changes indicate advance they should be welcomed. _Ray of Light._--The finest supposable element of light impression in the eye. _Beam of Light._--A number of rays. _Standard Colors._--As used in this system of color nomenclature, the best pigmentary imitation of each of the six spectrum colors red, orange, yellow, green, blue and violet and black and white. These are more specifically called _Pigmentary Standards_ in distinction from spectrum standards. _Spectrum Standards._--The six colors found in the solar spectrum and definitely located by their wave lengths, as follows in the ten millionths of a millimeter. Red, 6571; Orange, 6085; Yellow, 5793; Green, 5164; Blue, 4695; Violet, 4210. _Pigmentary Colors._--All colors used and produced in the arts and sciences. This is in distinction from colors seen in nature, as in flowers and the solar spectrum. The term refers not only to pigments in the strictest sense but to all surfaces coated, painted or dyed artificially. _Pure Colors._--A pure or full color, also called a saturated color, is the most intense expression of that color without the admixture of white or black or gray. All spectrum colors are pure, while no pigmentary color is absolutely pure, but the pigmentary color which approaches most nearly to the corresponding color in the spectrum must be selected as the pigmentary type of purity of that color. For example, the standard for green must be the best possible pigmentary imitation of the spot in the spectrum which by general consent is called green, and so not only for the six standards but for all their combinations which produce the other colors in nature. In pigmentary colors the term pure is entirely one of relative degree. As processes of manufacture are improved and new chemical discoveries made, there is good reason to believe that we shall have much more intense colors and hence much better imitations of spectrum colors than are at present possible. Therefore as our pigments become purer those now accepted as full colors will in time become tints or broken colors and new standards will be adopted. _Hue._--The hue of a given color is that color with the admixture of a smaller quantity of another color. An orange hue of red is the standard red mixed with a smaller quantity of orange. With the disks, pure hues are secured only by mixing two standards _adjacent_ in the spectrum circuit. For convenience in speaking and writing about colors in this system of color instruction, all the spectrum colors other than the six standard spectrum colors are designated as intermediate spectrum hues, and often for convenience in speaking of them they are called simply spectrum hues. To these are also added the colors between red and violet which are not in the spectrum. When so used the term must be considered as purely technical in this particular relation, because a color between the standard blue and the standard green is in the abstract no more a hue than either of these colors. If two standards not adjacent in the spectrum circuit are combined the result is not a _pure_ spectrum hue but always some _broken_ spectrum color. _Local Color._--A term applied to the natural color of an object when seen in ordinarily good daylight and at a convenient distance, as a sheet of paper at arms length, a tree at twice its height, etc. _Tint._--Any pure or full color mixed with white, or reduced by strong sunlight. In the disk combinations a spectrum color combined with white. _Shade._--A full color in shadow, i.e., with a low degree of illumination. In disk combinations a spectrum color combined with a black disk produces by rotation a shade of that color. In pigments the admixture of black does not usually produce as satisfactory shades of a color as may be secured with some other pigments, and each artist has his own preferences in making shades of the various colors on his palette. _Scale._--A scale of color is a series of colors consisting of a pure or full color at the center and graduated by a succession of steps to a light tint on one side and a deep shade on the other. _Tone._--Each step in a color scale is a tone of that color, and the full color may be called the normal tone in that scale. In art this word has had such a variety of meaning as to render it very convenient for Amateur Art Critics, together with such terms as breadth, atmosphere, quality, values, etc., but in the consideration of color it should have this one definite meaning. _Warm Colors._--Red, orange and yellow, and combinations in which they predominate. _Cool Colors._--Usually considered to be green, blue and violet, and the combinations in which they predominate. But it is, perhaps, questionable whether green and violet may properly be termed either warm or cool. The term cool as applied to colors is quite indefinite, except in a general way, but red, orange and yellow are universally considered as warm, and blue and green-blue as cool. _Neutral Gray._--White in shade or shadow. Pure black and white mixed by disk rotation. Black and white pigments mixed do not usually produce a neutral gray, but rather a blue gray. _Warm Gray._--A neutral gray with the admixture of a small quantity of red, orange or yellow. _Cool Gray._--A neutral gray with a small quantity of blue or green-blue. _Green Gray._--A neutral gray having combined with it a small quantity of green. As this color could hardly be classed with either warm or cool grays this fourth class of grays is suggested as helpful in giving definiteness to the more general color expressions. _Broken Colors._--Gray colors, often improperly called broken tints. For simplicity, a tint of a color is described as the pure color mixed with white and a shade as the color mixed with black, and the corresponding broken color is the same color
{'title': 'Elementary Color by Milton Bradley', 'source': 'Project Gutenberg', 'lang': 'en'}