>^\ r \ '^dr^l Co A*^t/ - FREE-HAND DRAWING LIGHT AND SHADE AND FREE-HAND PERSPECTIVE Art Students and Teacbers BY ANSON K. CROSS INSTRUCTOR is THE MASSACHUSETTS NORMAL ART SCHOOL AND IN THK SCHOOL OF DRAWING AND PAINTING, MCSKUM OF FINE ARTS, BOSTON ILLUSTRATED BY 32 PLATES BOSTON PUBLISHED BY THE AUTHOR 1892 COPYRIGHT, 1892, i:\ ANSON K. CROSS. ALL KK.IITS KKMCKVED. TYPOGRAPHY BY J. S. CrSIIlNr, ,e of a clear amber color. It may be turned into another bottle, and it too strong, diluted so that a drop will evaporate, leaving just a trace of gum. TRAINING OF THE ART STUD EXT. 29 is not so, for the subject is always the same, and the treatment should be the same in striving first for the masses and the effect. The most frequent error of all is the attempt to finish a part before the effect is indicated. Much time is spent in carefully drawing and finishing a part, only to find when the rest is in place that it is out of drawing or incorrect in values. The drawing should begin and progress all at once and equally until the desired effect of the masses is attained, when the detail may be studied. The more quickly the white paper or the canvas is covered, the better, and until the values and masses are nearly cor- rect nothing else should be considered. There are so many drawings and paintings which are merely conventional pretty things, that the student may have difficulty in realizing that they are not true, and that his work should be serious and honest. It is hoped that soon a higher standard may be placed before the art stu- dent, that he may understand that not all h in the drawing, but that values and cojor are equally_and even more important tjian^absolute form, and that he may acquire the power to represent Nature easily and truthfully. CHAPTER II. OUTLINE DRAWING. IT is often said that there are no outlines in Nature. In a way this is true, but it cannot be understood to mean that form is unnecessary or that it may be slighted. The student cannot learn to paint or to make pictures in any medium, without drawing the forms of the objects. The defining of the lights and shades and the various bits of color which are seen in Nature is necessary to give solidity and character to a picture, and it is useless to think that anything can be accomplished with color or light and shade if approximate representations of form cannot be made. Every object has definite form and size, and though it may not be outlined, it has boundaries. Although the representation of objects in outline only, is at best a conventional and imperfect means of expression, so far often as even form is concerned, the student can lie taught to observe effects, and may often succeed in con- veying a fair impression of the character of the object, and of varieties of surface and texture. He will find that the study of appearances and their representation, 3 OUTLINE DRAWING. 31 as fully as possible, even in so simple a way as outline drawing, will in great measure prepare the way for work in light and shade and color. The whole question is simply one of seeing, and the student should not trouble himself over technique, as his only aim should be a true representation of Nature. The most important points in free-hand drawing are freedom, directness, and accuracy. It is difficult to give directions which will produce these results, as individu- ality will prevent all from working in a uniform way, and handling and technique are of little importance. Since the production of truthful drawings is the end desired, it is of no consequence that such drawings are produced by different persons in different ways, but it may be well to give a few general directions. It is most important that the pencil should be held lightly, and the first lines of the drawing suggested freely and rapidly. The paper should be not less than eleven by fifteen inches, and the drawings should be large, as small drawings will produce a mechanical way of work- ing. A long pencil will assist to freedom of motion. It may be held as a stick of charcoal between the thumb and first two fingers, and as far as possible from the point. The paper should be fastened upon the board with its edges parallel to those of the board. If the edge of the paper is not straight, a horizontal line may be drawn 32 //.'// HAND I*K.\ \\'ING. near its lower edge, so th.ii dhe< li.m-, ma\ ].< referred to tin', hue. i; ( -i..ic attempting ti. draw any object. the student should ae<|inre the Iteedoin ol motion \vliidi is necessary to ;:>od woik. b\ diawin:; lines in :ill direc tions. ^Curved lines may be produced by _ pencil from the wrist, dhow, or BhoilWer;Iand_jti ly a motion of the entire arm. These inovements should lie |ii;ulised unlil lines (.in In- diawn instantlv the |u|iei in .m\ din-etion. This frc-e motion is most important for all sketohin: . l'ia_in fun hm^ or accenting .1 dr.iwing, whose |>ro|>snre will be re<|iiii cd. and the I'eiu il m.i\ lie held more linnlv :md ne.irer the point. The lirsl snlije. Is in. iv lie the -eometrie solids, or :mv common ol.jeets. I will e\|l.im the wav in which Ihe-.e in. iv be studied, lyv in.ikini; a sket< h ol a l>o\ with OVei thiown luck. (See l''i;;. ,|.) k / jU 4~~ I ii-.l, ne.ulv ( lo-.e the eves and try to see the box, not ..lid. but as a silhouette, the outline of the mass ol the box against the lueki;ronnd hem:; what should lirst be ( aieliillv studied. A little piaetiee with the e\ es neailv < lo-.ed will enable one to see the mass in this wav. ( 1 '; In order to leah/e the directions wliieh the ., appear to ha\e. lines max be diawn in the air. bv nun - in:; tlu- pen. al point so thai it appeal-- to eo\er the > \\hen this is done, care should be taken not to move the pen. il awa\ lioin the eyCS, that is. in the a. In al diree OUTI.IXK DRAWING. 33 tion of the edges, but to keep the pencil point where it would be if it were held upon a pane of glass plared directly in front of the student. This test is the mo^t valuable of all, because it is the simplest and easiest to apply. It is really the same as the use of the thread, explained on page 74, and nearly all other means of testing will at last be discarded in favor of this first and simplest. After careful study of the mass, its outline may be lightly sketched, no measurements of proportion having bern made. 1 The aim is to train the eye to see cor- rectly. In order to do this, the student must depend upon his eye, and put down its first impression, rather than the results of mechanical tests of proportions. He must first draw, and then test by measuring. When the^ outline of the mass has been sketched^ the inner lines may be drawn, and the result carefully studied to see that it agrees with the appearance. When it is jis near as can be seen, the drawing may be tested by meas- uring the proportions as explained on page 68. If_the sketch doesnpt agree with these tests, it must be changed. All changes should be made, not by erasing, but by drawing new lines, and the drawing should be^ carried on in this way, untiTthe correct lines are foumi._ The first lines must be very light. As changes are made, the strength may be increased to distinguish them, until the correct line is secured. The drawing having 1 These lines are approximate, and little time should be given them. See page 15. 34 FREE-HAND DRAWING. been changed to agree with the measurements of the whole height and width, and tested by moving the pencil point to cover the edges, it will be well to test, by means of vertical and horizontal lines, taken through the differ- ent angles of the box. Thus, drop the pencil point verti- cally from point i, and see where it cuts the lower edge, and carry the point horizontally from point 2, and note its intersection with the front edge. The pencil may now be made to continue the apparent directions of the edges A, B, C, etc., until the points where the continued lines appear to intersect the opposite outlines are noted. These tests may also be applied by the pencil used as a straight edge and held horizontal and vertical, and to appear to coincide with lines. These tests, if carefully made, will produce a drawing which is practically true, and should be depended upon. The first measurements of height and width should be very carefully taken. Distances which are nearly equal, as EF and FG, may also be compared, but as a rule, few measurements of proportion should be made, as short distances, or short with long distances, cannot be compared with sufficient accuracy to be of any value. (Fig. 6.) The thread may be used instead of the pencil for tests, as explained on page 74. The thread appears a fine line, whose intersections with the edges may be easily placed, so that until the eye can be depended upon the thread is preferable to the pencil. OUTLINE DRAWING. 35 It is most important that all changes be maclq not by erasing, but by drawing new lines. Erasing and keeping but one line from first to last will surely produce a hard and inaccurate drawing ; and although it may finally__be_ made to agree with all the tests, it will still be la .snjrit.. It is difficult at first for most students to draw lightly enough to secure the correct lines without too great heaviness, but it is better, rather than to erase, to throw the drawing away and start anew until the result can be secured without having lines so black that they cannot be easily erased. The reason for working in this way is that we wish the student to depend, as far as possible, on his eyes. If he erases and has one line from the start, unnecessary time is given to the drawing, and he will hesitate to erase his lines. If light lines are drawn and not erased, but others drawn as soon as there is doubt about the first being rightly placed, the student is much more free to change as each suggestion occurs, and toward the last he has his choice of the various lines already drawn and can experiment freely. This is by far the quickest and most accurate way, and prepares for rapid and truthful sketching. It is difficult at first for the student who has been taught the mechani- cal way of drawing one line at a time, but he will not have to draw very long in this way before he will be able to produce truthful sketches without drawing many unnecessary lines. 36 FREE-HAKD DRAWING. There is not much choice of pencils for this part of the work, but it is well to use always as soft a one as the nature of the work will permit. As no pressure should be used, the lead making at first as light a line as can be seen, and as all lines except the correct ones must be erased, there is no reason why the student who has diffi- culty in using a soft pencil should not use a hard one until the drawing is ready to accent. When the correct outline has been found, it is neces- sary to finish the drawing. The paper must first be cleaned, all the lines except the last being erased. The easiest way to reserve these lines is to make them stronger than the others so that they will show faintly, when the eraser has been passed over the paper, remov- ing all but an indication of the result. The drawing may now be accented with a soft pencil. The pencil may be held more firmly, and the lines drawn of their proper strength by one touch, the attempt being not to produce a fine even line in imitation of a ruled one, but rather a line of medium strength which will con- vey the idea of straight edges. For the present it is better for the lines to be made of uniform strength, with no attempt at gradation, or the frequent conventional accenting of the nearer edges by heavier lines. This point will be considered later, but we wish now to advise the student, if he is already familiar with it, to forget it as quickly as possible, and to finish in lines of one strength or as explained on page 44. OUTLINE DRAWING. 37 The student should draw from various objects in dif- ferent positions, until he is able to see them very nearly correctly at first. The time required for this will depend wholly upon the pupil and the care with which directions are followed. Groups. After the practice from single objects, several should be arranged in a group. The student will probably attempt to draw the objects one at a time, taking first the prism A, Fig. 7, next the vase B, then the cylinder C, and last the frame D. The objection to this way of pro- ceeding is that as the objects are drawn one at a time, until the last is completed, the proportion of the whole group that is, its greatest height in comparison with its greatest width cannot be seen. Indeed, this is often not even considered, the student taking it for granted that since he measured and tested each object as it was drawn, the single objects are correct, and therefore the group. But from what has been said it will be seen that each object is likely to be a little out of proportion ; indeed, we may say is sure to be so. This being the case, the errors are multiplied ; and if the height and width are compared, the proportion is found to be far from correct. It is a principle generally acknowledged that in all teach- ing the whole should be presented before its parts, and it cannot be contradicted that adding one object to another 38 1-KEE-JLL\D DRAWING. until finally the patchwork is complete is an uneduca- tional way of proceeding. Practically it is also most unsatisfactory, as with each object the difficulties in- crease, and at last it becomes impossible to place the drawings where they belong. The only logical way is to draw the group all at once, first considering it as a mass and blocking in its proportions by lines passing from the principal points, Fig. 8. When these lines have been drawn and considered, they may be tested by measuring the whole height and width, and the directions tested by use of the thread or pencil as explained. A good plan is, as soon as the proportions have been determined, to draw horizontal and vertical lines forming a rectangle enclosing the drawing, and to be careful that the drawing is kept within these lines. The proportions of the whole group being thus determined as nearly as measurements can determine, the objects may now be sketched by eye, the most important lines being drawn first. These are the lines whose positions and directions are most easily seen. They are the longest lines, lines of one object which are nearly continuations of those of some other object, and lines which are brought out dis- tinctly by shade or shadow. It is evident that in this way the drawings of the different objects are proceeding at the same time, and the shorter and less prominent lines being drawn last, the group may be said to be drawn all at once, or as if a single object having many parts. OUTLINE DRAWIXG. 39 While drawing, the student must think of the tests, applied by the thread, of horizontal and vertical lines, and of continued lines ; and drawing in the air by passing the pencil point to hide the edges to be represented, will help greatly. The object should be studied in this way and changed as often as found incorrect, until the eye can do no more. It is now time to apply systematically the tests explained by the drawing of the box. The first test is to compare the height and width of each object of the group, and also to compare these dimensions with those of the whole group. This test is the most important, and should be very carefully taken. Slight inaccuracy can hardly be avoided, but these dimen- sions are the longest measurements, and can be compared more accurately than any others, especially in the case of those which are nearly equal, and the best that can be done is to make the drawing agree wkh these measure- ments. By this time the student should be able to meas- ure as accurately as these drawings require. These tests will generally change the drawing through- out. The changes should be made, not by erasing, but by adding lines, and without other measurements until the eye can see no more to be done. The thread may- then be used, first for the tests of horizontal and vertical lines, second for the continuing of all the edges, and third for covering points in the group opposite one another, that the intersections of these diagonal lines with the 40 FREE-IIAXD DRAWING. edges may be noted. The thread used thus will discover every discrepancy except the slight deviations which only the accurate eye can detect. After the training which is given by these drawings made entirely by eye before any tests are applied, this accuracy will soon be secured. When the correct lines have been found, the others are to be erased, as explained on page 36, and the draw- ing is to be accented. But now the student will do well to think of effect, and to see if more interest and expres- sion cannot be given to the drawing than is given by uni- form lines. The student has perhaps been taught that the nearest objects are seen most strongly, and that the strength diminishes with the distance. This of course is true in a general way. It is the effect of aerial perspec- tive, or the changing of color by intervening atmosphere. Thus of a row of Hght objects the nearest will appear the lightest and brightest, and of a number of dark objects the nearest will appear the darkest. The light object in the distance appears darker, 1 and the dark one lighter, and in a sketch representing considerable distance this principle will be of assistance. But it must be stated so as not to convey the idea that there can be nothing in the distance as strong or stronger than the unimportant features of the foreground, for we do not see objects more or less distinctly according to their distance ; in fact, 1 Very light objects may change but little. OUTLINE DR. I \\~L\G. M distance has practically nothing to do with it. We tiistin- gitish objects as masses of color, lighter or darker than tlie L-olo_rs^ against which they arc seen. This being so, it is evident that a light object in the background, as a white house seen against dark foliage, must be much more prominent than a near object, seen against another of the same color. In general, when there is little or no contrast of color, objects are difficult to see without regard to their distance. Place a square of white cardboard in front of a larger square of the same, the latter coming in front of the blackboard. The smaller can be seen very faintly. In comparison with the distinctness with which the larger is seen against the blackboard, the smaller is practically invisible. This experiment proves that we distinguish objects through contrasts of color, and we have to con- sider what can be done in outline simply, to render the effect of Nature. Can no more be done than to repre- sent the form by lines of uniform strength ? The opinion seems to be general that more can be done. We find that instruction is often given to repre- sent the nearer edges by strong lines, the farther ones by light lines ; in fact, to proportion the strength of the line to the distance of the part it represents. Apply this rule to the representation of the two pieces of cardboard, and the nearer is accented by heavy lines, the farther by light lines. This is a direct contradiction of what we see, 42 FREE-HAND DRA\VL\C,. for the outline of the nearer is barely visible, while the farther is distinct against the blackboard. In color we certainly should not think of representing the nearer as darker than the farther, or in any other way than as it appears, and the same is true of light and shade. Why should we not do the same when possible, with outline ? No reason to the contrary can be given, for the difference in clearness with which the various lines are seen is the result, not of distance, but of con- trasts of color, and light and shade. Of course we shall expect to find the strongest lines among the nearest ones, but farther than this we cannot go, and if we adopt the conventional accenting recommended by text-books, we are working by rule and not by observation, and the result will be the production of hard, mechanical drawings. Character appears in outlines. An object, as a cast, having a smooth, hard surface shows these qualities in its outlines, which will be represented by smooth lines. A cube with smooth faces has sharp, straight edges, which will be represented by straight lines. A box made of rough boards has broken edges, whose character may be given by drawing the irregular outline in which one sur- face breaks into the other. A drawing from the figure can express the variations in the appearance of the cut- lines, parts of which are sharp, other parts blurred by light or a growth of hair. Light affects the appearance of the outlines strongly, OUTIJXR DRAU'lXG. 43 in some places making them distinct, in other places indistinct. An even line for everything disregards all these variations of effect ; so also does any conventional variation of strength. If the student is allowed to disre- gard effects in outline work, he will have great difficulty in seeing them in later work. There is no more labor involved in representing effects than in disregarding them, for one line is as easy to make as another, observa- tion only being required. The student who can see can perform, and as long as any differences can be found between his drawing and Nature, he can learn to correct the errors. The conventional accenting taught in the public schools produces the most mechanical, hard, and unnatural sketches when the student works from Nature, indoors or out. Undirected he would never produce such childish and ridiculous effects, but after his instruction in drawing from the object, where he has learned that lines must be represented with a degree of strength corresponding to their distance, he naturally does not think of observing and drawing what he sees, but simply mechanically grades the strength of line as he has been taught. He makes the heaviest lines of the drawing where there should be the faintest indications of lines, and often where no lines at all would be better than faint lines. It is almost impossible to get a student from the pub- lic schools to make sketches in which the unimportant 44 FREE-HAXD DRAWING. detail, which is no part of the effect, is not brought out with heavy black lines. This is not surprising, for he sees this detail and it is near him, therefore according to his instruction it must be strongly accented. In outline, as in other mediums, we should do the best we can to express what is before us. The effect of the subject should be considered as well as its form. There is no reason why the student should not be taught to observe the effect, and if once started rightly he will advance rapidly and will make drawings which, since they are representations of Nature, will have variety of effect, will be true, and artistic. No rule can be given other than to study and represent simply what is seen, as far as possible, as it appears. In outline, without any light and shade, it is impossible to always accent the lines just as they appear. For instance, some edges of the object may be so lost in the shade as to be wholly invisible, but without them the drawing might be incomplete and unsatisfactory. A correct impression of the facts must be conveyed. No important line can be omitted even if not seen, but otherwise the lines should be represented as they appear. In drawings of the geometric solids, where there are few lines in nature, it will sometimes be impossible to accent the lines as they appear, for some of the most important ones may be invisible, or seen so faintly that to represent them as they appear would make the draw- OUTLINE DR A \VL\G. 45 ing give a false impression. Frequently when the objects are strongly lighted their outlines on the light side of the group intersect one another, so that the outline of the mass is composed of parts of those of several objects. This outline is very prominent, while the edges inside the outline are almost lost in the mass of light. It is evident that in this case we cannot accent as we see. We must accent as we feel the group, and when accent- ing as the lines are seen is unsatisfactory, we must use our judgment and make the accenting express the facts in a satisfactory manner. When drawing from furniture or from any subject hav- ing many lines, the effect will generally be satisfactory when the lines are accented as they are seen. Here there are so many lines and so many changes in direction that the parts which are not seen will rarely be missed, and the student can represent more nearly what he sees. But it must be understood that it is wholly a matter of feeling for which no rule can be given. At first most students will have difficulty in seeing any difference in the way in which the various edges appear. This is due to the fact that but a single point can be clearly seen at any one time. The eye glances rapidly over the whole of an object, carefully observing all its parts. We are unconscious of this motion. All parts of the object are seen distinctly, and the variety of effect is not realized. All the parts will continue to give the 46 FREE-HAND DRAW IXC,. impression of equal strength until the ability to see the whole of an object at once has been acquired, as explained on page 18. It is not possible otherwise to see simply, to realize effects and masses, and the student must prac- tise until he can thus see before he thinks of success in any medium, for all demand equally a study of the com- parative strength of detail. Although no rule for accenting can be given, the effect is found to conform to the principle that any detail which comes in cither the mass of the light or that of Hie shade if unimportant. Thus an edge defining a light surface against another surface also light is not prominent, and an edge separating a surface in the shade from another shade surface is seen faintly. The important features are those which come between the light and the shade. CHAPTER III. INTERIORS AND GENERAL WORK. ALL drawing, whatever the subject, should be carried on in the same way, first by blocking in the mass of the whole, then the masses of the various parts, the detail coming last but always being carefully studied. In drawing from objects having curved lines, the stu- dent should be careful not to be content with the gen- eral effect of the line, but to give the variations from the regular curves found in many objects. Thus in a cast, lines which at first glance seem of uniform curvature will be found to be composed of many short, flat curves. Character will be given only by a study of these flat curves, but the search for straight lines must not lead to the drawing of straight lines where none can be seen, as in an ellipse. After the models, common objects as boxes, furniture, etc., may be drawn. These may be arranged in groups and an idea of pleasing composition be given. This work leads directly to the drawing of interiors. No principles other than those explained are involved. In this work, as in all, the aim should be to represent as 47 48 FREE-HAND DRAIVIXG. nearly as possible the actual appearance of everything. We obtain the dimensions of this appearance on a plane which is perpendicular to the direction in which we see the object. Carrying out this principle and extending the subject, we find that the surface which gives the appearance is that of a sphere, which cannot be devel- oped. This, then, is the reason why we cannot always draw just what we see, and it is impossible to make a sketch which shall include an extended range of vision, and give the exact appearance of each part, and a correct impression of the whole (pages 92, 93). The space which can be included in a model drawing. and which may be represented on a plane without notice- able distortion, should not include an angle at the eye of over twenty-eight degrees. If this is much exceeded the questions of the curvature of parallel lines for both horizontal and vertical distances will arise, but as most drawings require a larger angle the question must be con- sidered. The mind, knowing lines to be straight, will hesitate to accept their representation by curved lines, or knowing them to be vertical, will not readily accept their repre- sentation by inclined lines. The drawing should give the impression of Nature, as far as possible, even when the eye is not at the proper distance. The impression of vertical lines is given by vertical lines, and of straight lines by straight lines. For this reason, it seems best 1XTERIORS AXD GENERAL WORK. 49 that the student should represent what he sees, as nearly as possible, but in accordance with the perspective prin- ciple that straight lines shall be represented by straight lines. This will cause him to represent horizontal lines which extend on both sides by parallel horizontal lines, and to substitute for the curved lines found in objects at angles with the picture, straight lines extending to two vanishing-points. This will change the drawing very little, as shown on plate 28. When the subject is extended or comes very near the draughtsman, causing visual angles of from forty-five to one hundred degrees either horizontally or vertically, it is evident that the difference between the appearance and any drawing made on one plane will be very marked, and so.me parts of the drawing must be quite different from the actual visual angles formed in the eye. This may prevent the drawing from being truthfully blocked in as a whole at first. It can, however, and must in the beginning be placed as a whole approximately. The central part or the most important portion can then be drawn as it appears. The proportions of the outer parts ran be referred to the central, and the distortion, which is inevitable somewhere in an extended subject, be re- duced to the smallest degree by making the perspective of these outer and less important parts agree with that of the central and important mass. The different parts of an extended subject cannot be 50 FREE-HAND DRAWLVG. measured or compared by the ordinary use of the pencil, for its distance from the eye changes with every new posi- tion. If it is desired to compare the visual proportions, the pencil must be held at one distance from the eye by means of a thread attached to it and held at the brow by the left hand. When it becomes necessary to make a perspective drawing throughout, as sometimes happens when three walls of a room are to be shown, the proportions of this drawing may be very exactly found by holding the pencil in a plane parallel to the end of the room. This drawing should be avoided when possible on account of the serious distortion of its outer parts, and it will also be well to avoid representing one side of a room which extends far on both sides of the spectator. If one wall is to.be represented, it is better to draw from one end of the room than from the centre, as the lines will vanish and the distortion be less marked. When two walls are represented, the lines of both must vanish. When three are shown, the middle one must have no van- ishing. Figure 9 shows that if its lines vanish, the whole of the left wall will be outside of both vanishing points of the drawing, and thus very unpleasantly distorted. A drawing should never extent beyond ///< vanishing points of its lines. A very slight distance may be represented to the left of the left point in Fig. 9, when the drawing represents a LVTEKIOKS AXD GEXEKAL IVOKK. 51 court or any interior where the part at the left is a very unimportant portion of the drawing, but it is generally safer to end the drawing at the vanishing point. Distortion such as that in P'ig. 9, is seen in photographs taken with a lens of wide angle, and photographs, the most common perspective drawings, exert a strong influ- ence to perpetuate the serious distortions in the drawings of our illustrators and artists. In drawings of street scenes, etc., the lines are long and broken, and their apparent curvature may not be noticed if each part is drawn as it appears. In such subjects one does not know the conditions. The lines may be curved in Nature. Hence there is not the instant contradiction between the appearance of the drawing and the knowl- edge concerning the facts of the things represented. If the artist chooses sometimes to represent straight lines by curved lines, he has Nature as authority and the example of noted predecessors, and no one would wish to say that his drawing is not good or that it would be improved by plane perspective. In interiors and in street scenes, there is not only the question of horizontal foreshortening to be considered, but also that of vertical foreshortening. Whether or no this foreshortening shall be given is a question which can ' be answered only as it arises, and decided according to the conditions of the subject and the aim of the drawing. It is a question of the less important giving way to the 52 FKKE-IIAXD DR. Ill' IXC,. more important, and is for the artist rather than the stu- dent, who should, until he has attained by long practice ability to judge proportions correctly, never be permitted to draw other than those he sees. The unnumbered plates following are from students' drawings from Nature. Such work should be the aim of drawing in the public schools, whose pupils, taught to observe and to do what they see, may make a great advance-in this direction. The sketches are by students of the perspective cl at the School of Drawing anil Painting of the Museum of Fine Arts, and at the Normal Art School. They illustrate the beginning and the end of a course in model drawing, which is the only perspective necessary to the artist. CHAPTER IV. DRAWING IN THE PUBLIC SCHOOLS. THE value of a course in drawing when the subject is properly presented can hardly be overestimated, but it must be confessed that much of the instruction given is such that its benefit is a matter of doubt. At the beginning of his art education, the pupil should be taught to see correctly. When this has been accom- plished, and he is able to represent truly what is before him as it appears, and not as he thinks he sees it, then he is in a position to advance, and his personality may be cultivated. But as the first point to be gained is ability to see truly, it follows that we should from the very start demand truth, truth of outline, truth of light and shade, and truth of color. In beginning, I wish to say that drawing in the public schools can never accomplish results of any value until the pupils can observe for themselves ; in other words, until they can draw from objects instead of from draw- ings. This is impossible in many places now because the teachers have not materials. The schools must have models and all necessary materials, or the work will be 53 54 FREE-1IAXD DRA\\'L\ discover every error of (T.) A last test may be applied by holding two pencils together at right angles to the direction in which the object is seen, and separating them until one covers 2-3 and the other covers 5-6. If great care is taken, the directions of these lines with reference to each other may be seen, and the drawing tested by continuing these lines in the drawing. (T.) One way of measuring the apparent angle between lines is by folding a piece of paper and holding it so that each part appears to coincide with one of the two lines. This way is easiest applied 'by the use of a hinged rule or straight edge of two parts. I cannot recommend 74 FKEE-UAXD DK.l \VL\U. tare ('' not foreshortened "), they will appear horizontal and will place the thread correctly ; but if the horizontal lines of the subject are not thus situated, they will not appear horizontal, and so will ca- of level. It may seem that unnecessary i these directions, but it has been f to make many students understan the thread correctly, even after and illustrations. Some, after found holding the thread or penci ten to thirty degrees away from th it is thought that no explanatioi The problem is so simple that any succeed should have no difficult) that he will never learn to draw i .^ uui<_- 10 ins- cover his mistakes, and as the use of the thread is a most important test, it should be correctly applied. Any object, as the cube, Fig. 14, having been drawn, it may be tested by the thread as follows: Hold the thread horizontal to cover point 5. and note its apparent intersections with the edges 1-6 and 6-7. Hold the thread vertical in front of point 3, and see where it intersects 5-6. Hold it in front of 6-7, and notice its intersection with 2-3. Hold the thread to cover i and 5, also 2 and 4, and compare the directions with a hori- zontal line. Continue the edge 2-7 to intersect 5-6, and TESTS. 75 4-7 to intersect 21. Cover any opposite points as i and 3, 3 and 6, 4 and r, etc., and notice where the thread appears to intersect the edges between. This use of the thread is simply a more exact method of discovering angles than drawing lines in the air, the first method explained. When the eye is trained, the first, which is of course the simpler, is all that is needed. 1 5ut most students will find the use of the thread pref- erable, as it gives a fine line which can be made to exactly cover the edges of the object, and its intersec- tion with the edges can be seen much more readily than that of a line formed by a pencil or rule, which hides con- siderable of the object. If these tests with the thread are applied, they cannot fail to discover every error of importance. (T.) A last test may be applied by holding two pencils together at right angles to the direction in which the object is seen, and separating them until one covers 2-3 and the other covers 5-6. If great care is taken, the directions of these lines with reference to each other may be seen, and the drawing tested by continuing these lines in the drawing. (T.) One way of measuring the apparent angle between lines is by folding a piece of paper and holding it so that each part appears to coincide with one of the two lines. This way is easiest applied 'by the use of a hinged rule or straight edge of two parts. I cannot recommend 76 FREE-llAXD DRAM'IXC,. this test, for there are t\vo straight edges to be held at right angles to the direction in which the student looks, and it is so difficult to do this that I do not know of many students who have succeeded. Those who can hold the rules correctly, may depend upon their eyes and gi-t the drawing better without many mechanical tests than with them. (T.) Another way of testing the direction of a long line is to hold a straight edge upon the line of the draw- ing, and then lift the board and straight edge into the position of the picture plane, when the straight edge appears to coincide with the line if its direction in the drawing is correct. I have dwelt thus carefully upon each test in the hope that the student may reali/e their importance, for he will learn to draw correctly only through his own efforts, gaining with each discovery of error. He can never become a draughtsman as long as he depends upon a teacher for corrections. Let him carry his drawing so far that a thorough application of the tests explained will show no error, then as it is simply a question of exactness to be determined by the eye, if the trained eye of the teacher discovers mistakes so slight that the stu- dent cannot rightly be expertt-d to determine them, these may be pointed out. As the chief benefit results from what the student himself sees and does, he will be much better off without* a teacher than with one who does his work for him. TESTS. 77 As stated on page 23, the art student should use few- texts and should not require the mechanical aids to test- ing which have been explained. They may sometimes be required by teachers in the public schools, when students have no capacity for the work, but even then they will not be necessary if the glass is used to train the eye to see proportions, or as a means for testing. In all work, the student should aim to use few aids and to throw these aside as soon as possible. There are many who say that measurements and tests are mechanical, and that to learn to draw the student should draw by eye simply. It is true that measurements and tests, as unfortunately too many students are taught to use them, cannot fail to produce hard and mechanical drawings and retard progress. Still it seems better for the student, when he can see no farther, to be shown by tests where his eyes have failed, rather than to carry draw- ings only as far as he can by eye, and then put them away and begin others which can be carried but little if any further. Therefore the student is advised to apply the tests explained after he has carried his drawings as far as he can see, and not to put any drawings away which the tests show to be untruthful. It is believed that this* train- ing will most quickly produce ability to draw truthfully at sight. CHAPTER VI. PERSPECTIVE PRINCIPLES. (See Preface, page vii.) " OUR whole past, and especially the ideas and emo- tions of the present moment, determine how we perceive any object." This being true, the student must work long and earnestly before he can separate facts from appearances, as the knowledge of the actual form prevents the mind from accepting its appearance. The impression con- veyed to the mind of one not trained to accept the image of the eye, is the result of a combination of what tin- r\v sees with what is by far the greatest factor, what the mind knows concerning the actual conditions of the object. The student must struggle continually not only against this influence of his mind, but also against the effect which one line exerts to change the apparent directions of others. This effect is sometimes so strong that even the practised eye of the artist is deceived, and we may safely say that the most perfect eye, with the longest training, is liable to be deceived. A knowledge of the perspective principles governing the appearance of form 78 PERSPECTIVE PRINCIPLES. 79 is thus helpful to the draughtsman who would be truthful, and there is no reason why there should not be truth and artistic rendering at the same time. The Plane of the Drawing. The mind through the sense of sight perceives form, the rays of light from any object entering the eye, being focused on the retina, and forming an image of the object, as in the camera, except that in the latter the image is formed on a plane surface, while that in the eye is formed on a spherical surface. As but a single point can be seen clearly at any time, the image of the eye is practically the same as that of the camera. The artist's problem is to make his drawing so that it shall create the same ideas of form, size, and position as the objects which it represents. It is evident that this must occur when the drawing produces the same image in the eye as the objects. To do this the drawing must be similar to the image. The rays from any object to the eye form a conical body. If this cone of rays is intersected by any plane, the intersection is a picture of the object, which if the object is taken away, will still create its image in the eye. If this plane of the picture is at right angles to the cone, the section (the picture) will be a true picture of the object, that is, be similar to the image of the eye. it . 80 FRF.E-If.lXD DRA Figure 15 represents a circle A, placed vertical and in front of the eye. The cone formed by the visual rays is represented by lines b-b, and a vertical plane cutting through the cone of rays, by line P. If the student will hold any cone horizontal, it will perfectly illustrate the figure, the base of the cone representing the circle A, and the apex representing the eye. With the cone the student will at once see that a vertical plane between the eye and the base intersects the cone in a circle. This circle is the picture of the base A. Figure 16. If now the plane of the picture is inclined to the axis of the cone, its intersection with the cone is still a picture of the circle, but in shape it differs from that in Fig. 15, which is a circle. The oblique intersec- tion is an ellipse, but it is important to notice that it docs not appear such to the eye at the apex of the cone. It appears a circle exactly covering the base of the cone. It makes no difference how the plane of the picture is placed, or what the proportions of the resulting ellipse, it must always appear to the eye a circle, in fact, the circle of the base. When the eye is removed from the apex of the cone, the ellipse appears an ellipse, and is not a true picture of the circle. The circle of Fig. 15 and the ellipse of Fig. 16 are pictures of the circle A, and create in the eye, when it is at the apex, a circular image of the circle, but the former only is similar to the object A. When looking at pictures we naturally hold them in This must be at right angles u> me >mv.v t,^,. ........ the object is seen. The plane cannot be perpendicular to all the rays, but should be so to the central one. A " tme " picture of any object may be obtained by drawing upon a sheet of glass with a brush and color, or a special pencil, or on a wire screen with chalk. The gl iss or screen should be placed at right angles to a line from the centre of the object to the eye, the eye and screen held in one position, and lines drawn to cover all the edges which are seen. It is desired that every stu- dent make drawings in this way, a small pane of glass and a special pencil being the best materials. The drawings should be made with the glass at right angles to the rays. also when it is held obliquely. The drawings may be 6*JL tion is an ellipse, but it is important to notice that it does not appear such to the eye at the apex of the cone. It appears a circle exactly covering the base of the cone. It makes no difference how the plane of the picture is placed, or what the proportions of the resulting ellipse, it must always appear to the eye a circle, in fact, the circle of the base. When the eye is removed from the apex of the cone, the ellipse appears an ellipse, and is not a true picture of the circle. The circle of Fig. 15 and the ellipse of Fig. 16 are pictures of the circle A, and create in the eye, when it is at the apex, a circular image of the circle, but the former only is similar to the object \. When looking at pictures we naturally hold them in PERSPECTIVE PRIXCIPLES. 81 front of us, at right angles to our line of vision, as in the position of the plane P of Fig. 15. If plane P of Fig. 16 is thus held, the ellipse upon it appears an ellipse, and cannot create the idea of a circle. We see that the first picture is preferable to the second, for it is a circle, and wherever the eye is placed creates a circle in the eye. (It is of course understood that it is always looked at perpendicularly.) We will distinguish the first picture from that given by any other position of the picture plane, by calling it a y meaning that it is similar to the image created in the eye by the object. There can be but one position of the picture plane which gives a ''true" picture. This must be at right angles to the direction in which the object is seen. The plane cannot be perpendicular to all the rays, but should be so to the central one. A ' true " picture of any object may be obtained by drawing upon a sheet of glass with a brush and color, or a special pencil, or on a wire screen with chalk. The gl iss or screen should be placed at right angles to a line from the centre of the object to the eye, the eye and screen held in one position, and lines drawn to cover all the edges which are seen. It is desired that every stu- dent make drawings in this way, a small pane of glass and a special pencil being the best materials. The drawings should be made with the glass at right angles to the rays. also when it is held obliquely. The drawings may be 82 compared, and the student realize that the glass must be perpendicular to the direction in which he looks for the drawing to give the real appearance of the object. It appears that a drawing on any plane or surface creates the correct impression, only when the eye is in the position which it had when the drawing was made. All drawings, then, are best seen from some one point or distance. The trained eye will select this distance. As, however, drawings and pictures will be viewed by un- trained eyes, and as the proper point may not always be accessible, it is important that all should be avoided which causes marked distortion, when the picture is not seen from the proper point. If the picture is a "true" picture, the distortion produced when it is viewed from too long or short a distance, appears not in the shape of its parts, but only in the relative sizes of the objects represented. Thus the distortion of a " true " picture is always less than that of a drawing on a plane oblique to the visual rays, and the " true " picture is by far the best drawing that can be made for general use. It is called a Model 1 Drawing. Before beginning the problems, we will choose a term which shall mean the position in which any line appears its real length, and any plane its real shape. This occurs when the line or the plane is perpendicular to the direction in which it is seen, that is, is parallel to the picture plane. The words " parallel to the picture plane " PERSPECTIVE PKIXCIPLES. S3 might cause confusion, from the fact that in perspective the picture plane is gene-rally vertical, and takes in a wide field of view, while in Model Drawing the plane is perpendicular to the direction in which one looks, and is thus continually changing. We wish a term which shall mean the position in which any line appears its real length and any plane its real shape, and will select the words not foreshortened. Any line is "' not foreshort- ened " when its ends are equally distant from the eye, ami any plane when its angles are equally distant. We must also decide upon a term which shall mean the appearance of the facts instead of the facts. We select perspective!)'. " Perspectircfy " parallel thus means the appearance of parallel lines, which is that of conver- gence. " Perspectively " parallel lines are lines which converge towards a point, and " perspectively " equal distances on any line are unequal, the space representing the nearest of the equal distances being the longest, as in Fig. 24. x f>?0 The apparent angle at which parallel lines seem to converge, that is, the angle between the lines represent- ing parallel lines, we may speak of as large or small, and say that lines converge or vanish quickly or slowly. They vanish quickly when the vanishing-point is near the drawing, and slowly when it is far from the drawing. The angle which any line appears to make with a horizontal line that appears horizontal, we will call the f I 7te.tr S4 FREE-IIAXD DRA \\~IXC. angle of inclination. Thus all horizontal lines whose ends are not cilia-distant, appear to incline at smaller or greater " angles of inclination," according to the angle: which the lines make with the picture plane. Lines not level appear inclined at " angles of inclination " which increase with the angles of the lines with the picture plane and the ground. The " nn^ks of inclination " i>f horizontal lines increase or dec rease u>itli the ilistancc <>/ the ranisliing-point, that is, with the angle of convergence. In all the problems explained, the picture plane is supposed to touch the object at its nearest point, and the drawing is the largest possible to be made on a phme in front of the object. Stiuty i]f Principles. Figure i 7. Place a large cube a few feet distant from the eye, so that its centre is on the level of the eye, four of its edges vertical, and one face visible, with its angles equally distant from the eye. This face is " not foreshortened," and appears its real shape. Figure 18. Turn the cube so that its left side appears very narrow. It will be noticed that the upper end of the farther vertical edge B appears below the upper end of the front edge A, and that the lower end of the farther edge appears above the lower end of the front edge. The farther edge thus appears shorter than the PERSrr.CTl 1 7s L'KfXCrPLES. 85 front edge. It is also seen that the horizontal edges D and K, which connect the ends of these verticals, appear to converge. If these lines of the drawing are con- tinued, they will meet. The continued lines must be the representations of continuations of the edges, and we see that parallel retreating lines in Nature appear to con- verge to a point called their vanishing-point. V,r. \Ve now find that the right edge C is farther from the eye, and thus appears shorter than the central edge A, and the horizontal edges F and G appear to converge, as the horizontal edges of the left face. The edge C is much nearer the eye than B, and appears longer. It is really but little farther from the eye than A, and the con- vergence of F and G is very slight. As the eye is opposite the centre of the cube, the apparent distances that the upper ends of B and C are below that .of A must be the same as the apparent distances of the lower ends of B and C above that of A; and the "angles of inclination" of the upper edges D and G must be the same as those of the lower edges E and F. Since these edges appear equally inclined, they will appear to vanish on the level qf .the centre of the cube, that is, of the eye. If now the eye is lifted, the "angles of inclination" at the top decrease, and those at the bottom increase. When the eye comes to the level of the top of the cube, the upper angles disappear, and the whole top is seen as a horizontal line. /6 86 J-KEE-IIAXD DKA \VL\(J. From this study of the cube, we see, i st. That of two parallel and equal lines which do not vanish, the nearer appears the longer. The relative lengths appear to decrease as the distances increase. See Fig. 19, in which 1] being twice the distance of A from the eye, appears one-half as long as A. 2d. That parallel, retreating lines appear to converge towards a point, called their vanishing-point. (All lines whose ends are unequally distant from the eye are retreating lines.) 3(1. That horizontal, retreating lines appear to de- scend or vanish downward when the lines are above the level of the eye, and to ascend or vanish upward when they are below the level of the eye. This is evident from the fact that the eye must be dropped to look from the nearer to the farther end of the line above the eye, and be raised to look from the nearer end of the line below the eye to its farther end. 4th. That parallel, retreating horizontal lines appear to vanish at the level of the eye. 5th. That a horizontal hne at the level of the eye appears horizontal, and a horizontal plane at this level is seen edgewise, and appears a horizontal line. We will now draw upon the wall of any room lines which' have the apparent directions of the horizontal lines A, B, C and I), at floor and ceiling, which are per- - . A pendicular to the wall. We find that the lines on the he eye. Par- oint infinitely e transparent, continue on to converge. the continu- se Unes, (the point in the This point I lines is in a To draw the lines on the side of a room, two students must work together, one observing, the other drawing the lines with a straight edge. But the students may work individually by drawing a sketch of any room, the direc- tions of the perpendiculars to the end being determined by holding the thread or a ruler to cover the lines. This experiment proves that to see tJic vanishing-point of a sys- tem of parallel lines, u/i if /i extend on both sides of the spectator should be represented 1>\ parallel horizontal lines. The student should not be allowed any other way, but should treat all edges as " not foreshortened," when neither end face of the object is visible. In Nature there is no effect like that given by parallel perspective. The difficulties which have just been con- sidered are easiest settled by avoiding the question when possible, by moving so that an end appears and two van- ishing-points can be used, the drawing being between them. If one vanishing-point is in the drawing, as in Fig. 9, the drawing must be distorted, for when one line of a right angle vanishes toward the left, we expect to see 92 FREE-HAND DRAWING. the other vanish toward the right. When the question cannot be avoided in this way, and parallel straight lines extend on both sides of the spectator, they should be represented by parallel straight lines, and in the case of horizontal lines, by horizontal lines. Parallel straight lines in Nature appear curved. This is shown by the shadows of clouds at sunset, which some- times may be seen extending across the sky, converging in the west toward the sun, and in the east toward a point opposite the sun. Any straight lines which the mind does not know to be straight will, if long, produce the impression of curved lines. This is best shown by the rays of the electric search-light. In many drawings from Nature by our leading illus- trators, the curvature resulting from drawing tin* differ- ent parts of long lines as they appear, is very noticeable. Although the student may have difficulty in seeing the effect of curvature, even in long lines, he may very easily prove that curvature will result if he draws the parts, even of short lines, as he sees them. This may be done by drawing from three boxes or prisms, placed a short distance apart and in a straight line, the central box being directly opposite him, so that only two faces arc- seen. Figure 26 represents the appearance of the left-hand box, both sets of whose horizontal edges appear to van- ish, for two sides of the box are seen. PERSPECTIVE PRIXCIPLES. 93 Figure 27 represents the central of the three objects. Only one set of its horizontal edges vanishes, for since but one side is seen, the other set is " not foreshortened." Figure 28 represents the right-hand box, whose ap- pearance must be similar to that of the box at the left. The vertical edges of the objects at the sides are farther from the eye than those of the central one, and thus appear a little shorter than the edges of the latter, and if the long lines of the drawings are continued, they will form curved lines. Figures 26, 27, and 28 are each correct representa- tions of the appearance of a single box ; but if they are looked at all at once as a single picture, the impression of the objects being placed in a curve is produced. No one would think of making this drawing as a repre- sentation of three objects placed in a straight line. The drawing below, Fig. 29, would be made by all, but this drawing does not represent correctly the appearance of the boxes at either side, and it appears that to give the correct general impression, drawings sometimes cannot be exact in detail. There are some who think that the study of this ques- tion is unnecessary, that without theory all would natu- rally make the drawing, Fig. 29, as a representation of the three boxes. This is probably true ; but the knowledge that we see as we cannot always represent is very neces- sary, as is proved by the many illustrations from the pens 94 FREE-HAND DKAll'lXG. of those who fail to apply to a large subject the reason- ing which gives Fig. 29, and thus produce drawings which are flagrant violations of the simplest rule of per- spective, and this is frequently the result of the attempt to draw by eye the appearance of the parts of a large sub- ject (see page 49). Straight lines appear curved, but their representation by curved lines is generally unsatisfactory, and the stu- dent should never be allowed to represent straight In- curved lines. As shown on plate 28, straight lines may be substituted for the curved lines, changing the drawing very little when there are two vanishing-points. The influence of diagram perspective, and particularly the appearances of parallel perspective, are so powerful, that many illustrators do not realize that they do not see parallel perspectives in Nature, and that there must be two vanishing-points for the horizontal lines of any rec- tangular object, when two of its sides are seen. It is not necessary to advise the student not to make as one draw- ing the Figs. 26, 27, and 28, or not to represent the end of a room as curved; yet the draughtsman who would never think of making the latter mistake in the case of a single unbroken surface, will frequently do it when the surface is broken or when there are many short lines in different planes. Diagram perspective has created many false ideas, and is responsible for much bad drawing, and yet the per- PERSPECTIVE PRINCIPLES. 95 spective principle that straight, parallel lines have the same vanishing-point is absolutely necessary to the illus- trator. 1 Application of Principles to Drawings of the Cube. A cube with edges of four feet. Scale ]/% in. = I ft. Figure 30. The cube with four edges vertical, its lower face on the level of the eye, and one surface visi- ble with its lower edge AB " not foreshortened." The lower face appears a horizontal line. The upper edge CD of the front face is farther from the eye than AB, but unless the eye is very near the object, the face will be foreshortened so little as to appear practically its real shape. Figure 31. A cube with its top/our feet below the cube of Fig. 30. The receding horizontal edges vanish at point C, the centre of edge AB, because this edge is on the level of the eye, and a line from its centre to the eye is parallel to the edges. The front face is below the eye, and will be foreshortened, as shown by Fig. 32, so that its appar- ent height is less than its width. The edge EF is farther 1 Illustrators and artists, even the most noted, have made "parallel perspective " drawings from the earliest periods. The influence of the many strong painters who have used one vanishing-point when there was no reason for not drawing what was seen, and making use of two vanishing-points, probnbly accounts in large part for the frequent errors of the illustrators of the present time. 96 FREE-11AXD DRAIVIXC. from the eye, and appears shorter than the edge GH. It appears the length of 1-2. (This distance may be found by means of a plan of the cube, the picture plane, and the eye.) Connecting i-G and 2-H, the vertical edges are represented by inclined lines. This is not satis- factory. The model drawing must represent vertical edges by vertical lines. If verticals are drawn from G and H, the front face will seem too wide ; if from i and 2, it will seem too narrow. The proper effect will be given by verticals between these lines, or by verticals from G and H, the line 1-2 being dropped a little. The model drawing is not the exact drawing upon the inclined plane, but this drawing corrected by substituting vertical for inclined lines. Figure 33. The cube with its vertical faces at 45 to the picture plane, the top being on the level of the eye. The top is seen as a horizontal line. The sides, since at equal angles with the picture, appear of equal width, and the edges A and B vanish upward at equal angles which depend upon the distance of the eye. When hori- zontal lines are at angles of 45 with a vertical picture plane, the distance of their vanishing-points from the centre of the picture, (that is, line E,) is the same as the distance of the eye from the picture plane. The entire width of the appearance is the perspective of the diagonal 1-2 of the base of the cube, which is " not foreshortened." This line is behind the picture plane, Gcft (V Figure 34. The cube, with its lower face on the le\-ei of the eye, and its vertical faces extending to the left at 30, and to the right at 60. The left face is nearest parallel to the picture plane, and thus appears wider than the right face. The edges A and 1! vanish downward at angles which depend on the distance of the eye from the object, but the angle of A must always be less than that of B. For equal dis- tances of the eye, the width of the appearance must be less.when the faces are seen unequally, than when they are seen equally. The apparent width decreases as the cube is turned toward the position in which only one side is seen. Figure 35. The cube with its vertical faces vanishing equally, its top being four feet below the level of the eye. * Here the sides appear of equal width, and the " angles verticals between these lines, ui u^ . H, the line 1-2 being dropped a little. The model drawing is not the exact drawing upon the inclined plane, but this drawing corrected by substituting vertical for inclined lines. Figure 33. The cube with its vertical faces at 45 to the picture plane, the top being on the level of the eye. The top is seen as a horizontal line. The sides, since at equal angles with the picture, appear of equal width, and the edges A and B vanish upward at equal angles which depend upon the distance of the eye. When hori- zontal lines are at angles of 45 with a vertical picture plane, the distance of their vanishing-points from the centre of the picture, (that is, line E,) is the same as the distance of the eye from the picture plane. The entire width of the appearance is the perspective of the diagonal 1-2 of the base of the cube, which is "not foreshortened." This line is behind the picture plane, &H ' ^ PERSPECTIVE PRINCIPLES. 97 and so does not appear its real length. The exact length can be obtained by setting off the actual length of the diagonal on a horizontal line through the lower end of the front edge, and by drawing from its ends, lines to the point opposite the eye. The intersections of these lines with the lower lines of the drawing give the lower ends of the side verticals. Any known length can thus be measured on the pic- ture plane, and carried into the picture by means of parallel lines, which vanish at C, the point opposite the eye. Figure 34. The cube, with its lower face on the level of the eye, and its vertical faces extending to the left at 30, and to the right at 60. The left face is nearest parallel to the picture plane, and thus appears wider than the right face. The edges A and B vanish downward at angles which depend on the distance of the eye from the object, but the angle of A must ahvays be less than that of B. For equal dis- tances of the eye, the width of the appearance must be less.when the faces are seen unequally, than when they are seen equally. The apparent width decreases as the cube is turned toward the position in which only one side is seen. Figure 35. The cube with its vertical faces vanishing equally, its top being four feet below the level of the eye. |Q(X A/ t Here the sides appear of equal width, and the " angles / 3. Jk I f> r ' J > />^o 98 FREE-HAND DRAWING. of inclination" and convergence are alike on each side of the central edge. There are four parallel edges extend- ing to the right, and four to the left. Parallel horizontal lines appear to converge toward a point on the level of the eye, and there will be two vanishing-points. Since the edges are at equal angles with the picture, they will incline at equal angles, and the vanishing-points will he equi-distant on each side of the central edge. In this position of the square, which is the base of the cube, one diagonal, 1-2, is parallel to the picture (" not foreshortened ") and appears a horizontal line. The other diagonal, 3-4, appears a vertical line, and the farther angle of the square seems directly over the nearer one. M'hen the /<>/> of the cube is seen in this wa\\ the risible sides alwavs appear of equal width. The diagonals are perpendicular to each other, and it is seen that if two lines are perpendicular to each other, and one is "not foreshortened," the right angles appear right angles. Figure 36. The cube above the eye, its horizontal edges extending to the left at 60, and to the right at 30. Both sets of edges vanish at points in a horizontal line at the level of the eye (called the horizon), the point at the left being nearest to the drawing, for the line at the greatest angle with the pie tare appears (lie sJiortest. The diagonals of the horizontal surfaces vanish. Point 2 is N S3 99 left. The to be its 2, on the ouml, the tical face when the 45 to the >e vertical s directly i i and 2 >isect the ht at the spectively .earer enil i vanishes ing-point, ines. below the aring the It is thus , and the nish more .han tliose PERSPECTIVE PRINCIPLES. 99 the nearer end of 1-2, which vanishes to the left. The other, 3-4, vanishes to the right, for 3 is seen to be its nearer end. Figure 37. The cube resting on an edge, 1-2, on the ground, with four of its faces at 45 to the ground, the eye being above the object, and the right vertical face being visible. The edge on the ground vanishes to the left, when the right vertical face is seen. If four faces are at 45 to the ground, the diagonals of the other faces must be vertical and horizontal lines. The upper edge, 3-4, is directly over the edge on the ground, and verticals from i and 2 contain 3 and 4. The horizontal diagonals bisect the vertical diagonals, and vanish toward the right at the level of the eye. Points 5, 6, and 7, 8, are perspectively equi-distant from the vertical diagonals. The nearer end of 5-3 is 5. This line vanishes upward, and 5-1 vanishes downward. Parallel lines have the same vanishing-point, and the other oblique edges vanish with these lines. Figure 38. A cube resting on the ground, below the eye, with its vertical faces visible and appearing the widths AB and AC. The face AC appears narrower than AB. It is thus at a greater angle with the picture than AB, and the horizontal edges extending to the right must vanish more quickly, and at greater " angles of inclination " than those extending to the left. 100 FREE-IIAXD DRAll'lXG. " The Right Square Pyramid. The axis of this pyramid is perpendicular to the base at its centre. This point is found by drawing the diag- onals. Figure 39. When the base of the pyramid is horizon- tal, the drawing may be tested by a vertical line from the centre of the base. This should contain the vertex of the pyramid. When two sides, AB and CD, of the base are " not foreshortened," they appear perpendicular to the axis, and one side only of the pyramid is seen if it is long or if it is above the eye. (Fig. 39.) If the axis is short or wholly below the eye, three .of the triangular faces will be visible, the two outer ones appearing alike. (Fig. 40.) One, two, three, or four sides, or the base with one, two, or three sides, may be visible at one time. Figure 41. When two sides are seen, all the edges of the base appear to vanish. When two sides appear alike, the edges vanish at equal angles. The farther slant edge is just behind the nearer. One diagonal of the base, 3-4, appears to coincide with the axis of the pyramid, and the other, 1-2, appears at right angles to it. Figure 42. When two sides are seen unequally, the axis of the pyramid appears perpendicular to a line which is parallel to the picture plane. A plan of the base and PERSPECTIVE I'KlXCiri.ES. 101 the picture plane will show the position of the line ab with reference to points i and 2. It passes behind 2, the nearer point, and in front of i, the farther point. When the pyramid is vertical, ab appears horizontal. When oblique, as in Fig. 43, the line ab has the same relative position, passing in front of the farther angle of the base i, and behind the nearer angle 2. 77ie Triangle, and tlic Triangular Prism. Figure 44. When the triangle is equilateral or isosceles, and its base is a horizontal line, the altitude of the tri- angle is a vertical line, and intersects the centre^ of the base. Figure 45. When neither end of the prism is seen, its long edges are " not foreshortened," and must be repre- sented by parallel lines. Points i and 2 are in perpen- diculars to the long edges, passing through the perspective centres 3 and 4, of the lower edges of the triangles. Figure- 46. When an end is seen with two sides which appear alike, one edge, A, of the base is " not foreshort- ened." The central, I>, of the receding edges appears at right angles to this edge, and the end does not appear its real shape. Figure 47. When an end and a side are seen, the drawing may be tested by a vertical line through point i. This vertical should intersect 2-3, nearer 3 than 2, for 102 FSEB-HAND DRAWING. the nearer half of any retreating line appears longer than the farther half. The edges of the end vanish in the direction of their farther points, which are at once seen except in the case of the edge 1-2. If line 3-7 appears to intersect the centre of 1-2, edge 1-2 is "not foreshortened " and does not vanish. If 3-7 intersects 1-2 nearer 2 than i, point 2 is the nearer end of the edge 1-2. If 3-7 intersects 1-2 nearer i than 2, point i is the nearer end. The prism is so placed that the edges of the face on the ground are at equal angles with the picture. The length of the prism is twice that of the edge of its base. The edges 2-3 and 2-6 vanish at equal " angles of incli- nation." The nearer half of 2-6 appears as long as 2-3, the farther half, a little shorter than the nearer. The Regular Hexagon. In the hexagon there are four sets of parallel lines, as A, B, C, and D, in Fig. 48. Its diagonal, 0-4, is divided into four equal parts by the diameters D and the diagonals B and C. A drawing of this form will be tested by seeing that the parallel lines vanish in the directions of their far- ther ends, and that the diameters intersect the diagonal so that the points in it are perspectively equi-distant. Figure 48 represents the hexagon when its centre is at the level of the eye, and it is " not foreshortened." PERSPECTIVE riUXCU'LES. 103 Figure 49 represents the plane after it has been revolved away from the spectator about angle o. A vertical line, the real length of a. diameter, through o, will be a side of the rectangle shown in Fig. 48 enclosing the figure. The receding sides of this rectangle vanish at the level of the eye. The farther side is a vertical through 4, whose position is determined by comparing the apparent width of the foreshortened figure with its height. The diagonals of the rectangle give the centre of the hexa- gon. A vertical, /', through the centre, bisects the rectangle, and diagonals from b to o anil 4 give points 5 and 6 in the diameters of the hexagon. The di- ameters intersect the sides, giving the length of the sides A. Figure 50 represents the hexagon in the same position as Fig. 48, except that a diagonal is vertical. Figure 5 1 represents the foreshortened hexagon, when revolved back about side A. The enclosing rectangle is drawn as in Fig. 49. Its diagonals give the centre of the hexagon, through which passes the diagonal parallel to side A. Its ends, o and 4. are angles of the hexagon. The vanishing lines D, from the nearer side A, give the farther side. Figure 52. The hexagon having been sketched from the object, to test the drawing (assuming the diameter Al] to be correctly placed), Draw CD, which will be horizontal, (parallel to AB,) \ 104 1-KEE-1IAXD DKA //V.V(/. when point 4 appears over o. Draw AD and BC. See that o-i is greater than 1-2 and 3-4 less than 2-3. Figure 53. To test the sketch (assuming the nearest side to be correctly placed), Draw the diameters AC and Bl), and the diagonals AD and BC, giving point 2. Through 2 draw 0-4. See that the points on this line are equi-distant, actually equi- distant when the line is "not foreshortened," and per- spectivety so when the line vanishes. The Hexagonal Prism and Pyramid. Figure 52 may represent the top of a vertical prism, two of whose sides will be seen equally when 4 appears just over o. The side o-A inclines at the same angle as o-J), at both the top and the bottom of the prism, though the angles of the lower lines are greater than those of the upper. "When two sides are seen equally and the prism is not vertical, the directions of the lines o-A and o-J> may be determined by means of the diameters AB and CD of the hexagon, which appear perpendicular to the axis of the prism. Figure 53 may represent the top of the prism when three of its vertical faces are seen, the two outer ones appearing of equal width. ^Yhen thus seen, the edges AT. and CD of the ends appear perpendicular to the axis of the prism. PERSPECTIVE PRIXCIPLES. 105 Figure 54 represents the prism when three faces appear of unequal widths. The narrower A is the farthest from the eye. Points a ami c are thus farther from the eye than b and and < and <, that of the larger ellipse, comes in front of the centre of the square O, and also in front of IK, the long axis of the smaller ellipse. Points E, G, O, H, and F are equi-distant in the diameter of the larger circle, and divide it into four equal spaces, which appear perspectively equal. The diameter CD of the circle is " not foreshortened," and 116 1-KEE-UAXD DKAM'IXG. the equal divisions upon it appear equal. The diameter CD is not the long axis of either ellipse, but is parallel to them, and generally there is so little space between them that practically we may say that the equal divis- ions on the diameter of the circle appear in the long axis of the ellipse, and if the distance Al between the ellipses, measured horizontally, is one-fourth of the entire long axis Al>, the distances EG and HF are per- spective fourths of the entire short axis EF. The apparent distances at front and back, between ellipses representing concentric circles, are always the same perspective parts of the entire short axis, that the distances between the ellipses on the long axis are of the entire long axis. The distance between the long axes of the ellipses is equal to one-half the difference in length of HF and EG. Figure 75 represents concentric circles more nearly ;-s they generally appear, the distance FG being but little shorter than Al, and the long axes of the ellipses thus being very near together. The distance 5-6 is one-sixth of the axis 0-6, and shows that the spaces A1J and FG must be perspective sixths of the short axis AG. The drawing shows that the retreating parallel circles do not appear to converge except beyond the centre of the cir- cle. Thus, curved parallel retreating lines 'may appear to converge or diverge. PERSPECTIVE PRINCIPLES. 117 Figure 76 represents a circular ring, a cross-section of which is a square. The circles are concentric on each side of the ring. The distance 4-8 is actually one-seventh of the long axis, and the distance 2-9 is a perspective seventh of the short axis. The square which is the section of the ring appears very nearly its real shape at the ends, the horizontal side 4-8 appearing a little longer than the vertical 3-4. The distance 1-2 at the front, is longer than 3-4, and at the back 5-6 is a little shorter. The invisible lines should always be sketched, so that the lines which are seen may have the right direction. Care must be taken not to exaggerate the distance between the long axes of the ellipses. In many cases it will not be necessary to draw more than one line as a test for both ellipses. Tlic Frustum of the Pyramid and the Cone. When any pyramid is cut by a. plane parallel to its base, the section is similar to the base and the lines of both figures are parallel. Figure 77 represents the frustum of a square pyramid. This is a form frequently found in furniture, chairs, tables, etc. The drawings from these objects may be tested by seeing that the slant lines, when continued, meet at a point over the centre of the base, and that the lines of the upper base are parallel to those of the lower. 118 FREE-HAXD DRAW IXC,. Figure 78 represents the frustum of a cone below the eye, with the larger base A visible. The contour elements of the cone appear tangent to the ellipses of both bases and, when continued, meet at a point in the axis of the cone. The smaller base is invisi- ble, and thus, being more distant, appears proportionally wider than the visible. Figure 79 represents the same object, but seen from a nearer position, the ellipses appearing wider. The contour elements are tangent to the ellipses farther from the ends of their long axes, and thus less of the con- vex surface is visible. A circle A, half-way between the two bases, is represented by an ellipse tangent to the con- tour elements, and perspectively half-way between the ellipses of the bases. The nearest element of the cone appears a vertical line and extends from its upper end b away from the eye. Its centre i thus appears nearer a than b. The farther element of the cone is nearer the position in which it is " not foreshortened," and point 2 is practically midway between c and d. The width of the ellipse is proportionally greater than that of the upper ellipse, but less than that of the lower. Figure 80 represents the cone with its smaller base visible and a conical band about its surface. The ele- ments are tangent to the ellipses behind the ends of their long axes, and more than half of the convex sur- face is seen. As already shown, the visible curved sur- PERSPECTH'E PRINCIPLES. 119 face 01 the cone may vary from none to all. Circles or bands about the convex surface will be visible in the same proportion as the surface of the cone ; less than half the ellipses being seen when the larger base of the cone is visible, and more than half when it is invisible. The apparent thickness of the ring or band, at the short and long axes of the ellipses, is given by the test for concen- tric circles. Figure Si represents a frustum of a cone and a circle between the two bases. The apparent width of bands A and B varies with the angle of the cone and the position of the eye ; but this is a question of little importance, for the proportions of the ellipses can always be easily determined as explained, and the ellipses being correctly placed, the spaces be- tween must be correctly represented. Figure 82 represents a dish of conical form. The nearer side of the dish is foreshortened more than the farther, and thus appears much narrower. The rela- tive widths depend wholly upon the position of the eye. If lifted, the front appears narrower until it is seen edge- wise, and if farther raised, all the inner surface is visible. An elevation of the object, representing the position of the eye, the picture plane, and the visual rays will assist in obtaining the proportions of the model drawing when it is made without the object. When drawing from the object, if the appearance of any part is not clearly under- 1 >U l-REE-HAXD DR. 1 II r /NC . stood, this elevation will often help to make the princi- ples clear. Figure 83 represents a double cone, composed of intersecting cones A and B, whose bases are four inches in diameter, and whose axes are six inches. The whole length is eight inches. The elements converge to points in the axis of the double cone, which are equidistant from the bases and from the intersection of the two objects. The smaller circle is common to both cones, and the ellipse which represents it must be tangent to the elements of both cones. Less than half the surface of A and more than half the surface of B is visible. It follows that the ele- ments of the farther cone, B, must appear to intersect those of the nearer one, A. When the cones are much foreshortened this point is prominent, as in the sketch at the left. The Torus and Ring of Circular Section. The torus is a convex moulding frequently found in architecture, and in many common objects. Figure 84. An easy way to draw this form is to sketch the ellipses representing the circles, which may be con- sidered its bases. The section of the surface connecting these bases appears nearly its real shape at the ends of the long axes of the ellipses. (The semicircle in this PERSPECTIVE rRIXCIl'LES. 121 position below the eye appears half of a horizontal ellipse.) The curved contour of the moulding will be represented by a line tangent to the semicircle, and nearly so to the upper and lower ellipses, or, if the ellipses are wider, farther above and below the ellipses. Figure 85 represents the ring. This object will be rep- resented by concentric circles, when it is "not foreshort- ened," but when foreshortened, its outlines will not be ellipses. This is due to the fact that the outer visual rays are tangent in front below the centre of the ring, and be- hind above the centre. Thus the line on the ring which is on the contour is not a circle. When much foreshort- ened, the inner outline of the farther part will pass behind the outline of the nearer part, as in the drawing. The centre line of the ring is a circle which, if seen, would appear an ellipse. Suppose a sphere of the diam- eter of the section of the ring to move, with its centre in the circle, around the circle. The sphere would describe the surface of the ring. The sphere will be represented in all its positions by a circle. '\Yhen behind, by a circle slightly smaller than when in front. The outline of the ring must be represented by a line tangent to the circles representing the sphere. Its outlines arc thus ray nearly parallel to the ellipse representing the centre of the ring. It should be noted that if a line is parallel to an ellipse, it is not an ellipse. Parallel ellipses are impossible. 122 FKEE-1IAXD DKA II /.\ G, Frames. In the frames of regular shapes are found concentric polygons. The angles of the inner figure being in the diagonals of the outer, this point enables us to test draw- ings of these objects. Figure 86 represents a cubical frame. The diagonals of any face, as ABCD, contain the angles of the inner square, any line of which being drawn, gives points in two other lines. Any angle of the object is an end of three lines. Thus, from E extend EF, EG, and EL. Continue any inner line to an outer edge of the object, and a point in the continuation of a second inner line is found. Thus, EG continued to AB gives point i, which is in IK, and EF continued to the top, gives a point in an inner edge which extends to the left. Figure 87 represents an equilateral triangular frame. The angles of the inner triangle are in perpendiculars to the centres of the opposite sides. These lines inter- sect each other at the centre of the triangle. Any side of the inner triangle, as A, gives points i and 2 in the other sides, B and C. Any side, as A, may be continued to the outer triangle, giving 3. From 3 a parallel to the short edges gives 4, which is in the edge D, parallel to A. Figure 88 represents a square frame with a circle \ tangent to the inner square. PERSPECTIVE PRINCIPLES. 123 The student will probably draw the long axis of the ellipse representing this circle parallel to either the side or the diagonal of the square. The long axis is parallel to the side, when one outer side only, as B, of the square frame is seen. It is parallel to the diagonal only when two sides, as B and D, are seen equally. It is generally parallel to neither. The long axis is perpendicular to the axis of the cylin- der, of which the circle is the base. The direction of the axis of the cylinder is that of the short edges of the frame. A parallel to these lines, through the centre of the square, will be the short axis of the ellipse. The ellipse is tangent to the square at points a, l>, c, and d in vertical and perspectively horizontal lines through the centre e. The long axis is perpendicular to, and bisects the short, and comes in front of the centre of the square. Figure 89 represents a reading-glass, and illustrates the fact shown above, that the direction of the long axis of the ellipse must not be referred thoughtlessly to any other lines of the object. The student who does not observe, will draw the long axis of the ellipse in the direction of the handle of the glass. It may, by chance, have this direction, but its direction may be very different. The handle radiates from the glass, as a spoke from its hub, and its direction may be that of any one of the many spokes in the wheel. Figure 90 is an elevation, and Fig. 91 a model draw- 124 FREE-HAND DRA \VL\G. ing of a cylindrical object having a moulding and grooves about its surface. Figure 90 represents the picture plane, and the visual rays converging toward the eye. These rays intersect the picture plane, and give upon it the positions of the various points to which they pass. The upper form, A, is that of the torus, explained on page 120. The central, B, is the reverse of this form. The cir- cles appear lines, 5-6 and 7-8, in the elevation. The rays to these points intersect the picture plane, and give the short axes, 5-6 and 7-8, of the ellipses. The curved lines N and M, if visible, end above the long axis ot the ellipse. Form C is that of the double cone, explained on page 1 20. ]~asr Forms. Figure 92 is an elevation representing the vase shown by the model drawing, Fig. 93, in which a common mis- take is shown at the right side of the drawing, where the line representing the body of the vase extends to the long axis of the ellipse of the neck. The outline of the body must at least pass tangent to the ellipse, as at the left, and it may pass above the ellipse. The neck of the vase thus extends inside the outline of the body. PERSPECTIVE PRINCIPLES. 125 When the top of the vase is at right angles to the axis its circles are concentric, and appear as in Fig. 75. Figure 94. When a handle projects from the side of the vase, its thickness breaks the outlines. When the handle extends toward the eye, the line of intersection appears fuller and more nearly its real shape, the more the handle is foreshortened. Figure 95 represents the bottom of a vase, whose actual form is indicated by the light lines of the section. The lines of the stem appear to end above the centre of the ellipse, for any conical form which extends toward the eye must have more than half of its surface visible. Figure 96 is an elevation of a vase, the picture plane, and the visual rays. The rays, intersecting the picture plane, give the posi- tions and the lengths of the short axes of the ellipses representing the three plinths, A, B, and C. These being drawn, the other lines of the model drawing, Fig. 97, are readily placed. The curved lines of the neck appear above to intersect the lower ellipse of plinth A, and below, they end above the long axis of the upper ellipse plinth B. The body of the vase is represented by a line tangent to or above the lower ellipse of plinth B. Figure 98 is an elevation of the lower part of a vase with a spherical shaped body and a cylindrical base having a curved moulding. 126 FREE-HAND DRA ll'IXG. The curved edge may be drawn as the torus. The body of the vase is represented by a line tangent to the ellipse of the upper base of the plinth, at points depend- ing upon the position of the eye. When the ellipses are narrow, the line will be tangent near the ends of the ellipse, as in Fig. 99. When wider, the tangent points may be near the short axis (Fig. TOO). If still wider, the curve of the body appears a continuous line covering part of the base (Fig. 101). Figure 102 is an elevation of a vase whose appearance, (to the eye situated at the point of convergence of the visual rays,) is given by Fig. 103. The elevation gives the positions and lengths of the short axes of the ellipses representing the different circles. The long axes are shorter than the actual diameters of the circles, because they are behind the picture plane. The upper edge of the vase is conical. The short, straight lines, a, a, tangent to the two ellipses, B and C, will be seen until the larger ellipse C is wholly visible. The student who has a knowledge of Orthographic Projection may test his ability to draw from a description of the form and its position, by taking any sheets of pro- jection showing objects one after another, supposing the objects to be seen from a certain point, and making model drawings which shall represent them. Thus, Fig. PERSPECTIVE PRINCIPLES. 127 104 represents several objects, and their relations to each other, and the planes of projection. Figure 105 is a model drawing of the same, and sup- poses the objects to be seen from the left and from above, so that three faces of the cube are visible. The cube is the first object, and any drawing which shows the top, front, and left sides, answers the require- ments. When the cube is correct, the ground-line which is parallel to the edges extending to the right should be drawn. The cone is the next object. Its base is a circle of the same diameter as the base of the cube. The best way to place the ellipse, which is the appearance of this circle, is to draw a square whose sides are parallel to the base of the cube. The ellipse must come tangent to the square at its diameters. The distance between the cone and the cube is equal to half the side of the cube. In perspective this distance 1-2 will be found by drawing the diagonals of the right front face of the cube. Setting off this distance on line AB, from 2 to 3, gives the nearest angle of the square. Its sides extending to the right are continuations of, and are perspectively equal to those of the first square ; and the sides extending to the left are parallel to those of the first. It should be remembered that these lines continue, and vanish at right and left in a horizontal line at the level of the eye, and all parallel lines should be continued as far as the drawing will 128 FREE-HAND DRAWING. allow, so that they may be given the proper convergence. The student should not attempt to have the vanishing- points come on the paper. The diameters of the base give the tangent points of the circle and square, and through them the ellipse must pass. The circle is ]iori- zontal, and the axis of the ellipse is a horizontal line. The distance between the centre of the ellipse and the centre of the square is so slight as to be hardly notice- able. The long axis of the ellipse is, however, in front of the centre of the square ; and in a larger drawing, where the ellipse is wide, if the axis should be drawn through the centre, the difference would be very notice- able. The axis passes through the centre of the square, and must be represented by a vertical line. Its length is readily determined by reference to the vertical edges of the cube, which are half as long as the axis. The cylinder is next to be considered. The nearer circle is in the plane of the front face of the cube, and it will be best drawn by means of the square which circum- scribes it. The sides of the square are parallel and equal to those of the right front face of the cube. Of course the distance 5-6 must be less than 3-4, as 3-4 is less than 0-2, and 4-5 is less than 2-3 (see Fig. 24). The diagonals of the square give its centre, and through this point the axis of the cylinder is drawn. The vertical and horizontal diameters give four points in the ellipse, whose long axis is a little in front of the centre of the square. PERSPECTIVE PRINCIPLES. 129 and at right angles to the axis of the cylinder. In the same way, the farther end may be drawn. The length of the cylinder being twice the side of the cube, the dis- tance 7-8 is perspectively equal to 5-7. The hexagonal prism is the last object. It is vertical, with one face in the plane of line AB. A diagonal of its base is parallel to AB. Its length may be placed on AB, from 9 to 10, perspectively equal to 5-6, the dis- tance 6-9 being perspectively equal to 4-5. Points n, 12, and 13, (dividing 9-10 into four perspectively equal parts.) being placed, the diameters of the hexagon extend from IT and 13 toward the left-hand vanishing-point. The side 14-15 having been drawn, the diagonals 11-15 and 13-14 give the centre of the hexagon. Through this point the diagonal parallel to 11-13 passes, and the lines from 9 and 10 place in it the two remaining angles of the base, 16 and 17. The left vertical face A appears narrowest. This shows that 16 is nearer than 13, and the diameter 16-13 inclines upward slightly from 16. These drawings call for lines at definite angles with the ground and the vertical plane. Such angles may be de- termined by means of the cube, and for this reason it will be well to draw this object first, even when it is not called for. The edges of the cube, Fig. 106, being perpendicular to the two planes, the diagonals of its faces are at 45. If smaller angles are desired, they can be obtained by 130 FREE-HAND DRAWING. subdividing the angles of 45. In making this division, it must be noticed that equal angles never appear equal u'hen occupying different positions u>ith regard to the pic- ture plane. Figure 107 shows that equal angles appear unequal, and larger, the more the lines of the angles are foreshort- ened, so that to divide Any angle, the part which is most foreshortened must be represented by the greater angle, and as equal angles approach the position in which they are " not foreshortened," they will appear smaller. By holding a triangular card, the student will see that an angle less than 90 may appear greater than 90, when its sides are much foreshortened. In fact, the small- est angle may appear any angle up to 180. An angle greater than 90 may in the same way appear any size up to 1 80. When the plane of the angle is foreshortened more than the sides of the angle, the angle appears less than its real size, and any angle may appear the smallest possible to be measured. It is thus seen tliat an angle ma\ appear an\ angle from the s in a I lex t up to 180 Such practice will more quickly than any other work show the student whether he really understands the prin- ciples, or has been merely memori/.ing them. The latter, which unfortunately is the only way many study, will be found entirely useless, and those who have been working thus, must start again with the determination to see with PERSPECTIVE PRIXCIPLES. 131 their own eyes, and to accept nothing which they have not verified by careful study. The principles which have been explained enable one to see as it is impossible to see without them, to draw without the objects, to draw from memory, and to design geometric forms of any size and in any position. They are of so much value to the practical draughtsman that he cannot afford to be without them, even were it very difficult to obtain this knowledge. The principles are, however, so simple that there is no excuse for violations of the few essential ones ; yet such violations are found very frequently, not only in the work of the amateur, but also in that of the professional draughtsman. Although the principles must be carried out in all good drawings, theory alone should be depended upon only when designing or drawing imaginary subjects. When Nature can be studied, the rules may be applied after careful consideration of the appearances, and it is not intended or supposed that the principles will render this study of Nature unnecessary. When understood, they are of most value in assisting the mind to accept the image of the eye, and arc unconsciously applied. Rei'icii.1 of Important Principles. Any line whose ends are equally distant from the eye appears its real length. Any plane whose angles are equally distant appears its real shape. 132 FRl-.E-lIAXD DKAll'lXG. 2- Parallel, retreating lines appear to converge, or vanish toward a point called their vanishing-point. ? Of two parallel ami equal lines which do not vanish, the nearer appears the longer. u. Equal spaces on any retreating line appear unequal, the nearest appearing the longest. All lines whose ends are unequally distant from the eye are lines which appear to vanish. Horizontal, retreating lines, above the eye, appear to descend, or vanish downward. Y Horizontal, retreating lines, below the eye, appear to ascend, or vanish upward. X' Parallel, retreating horizontal lines appear to vanish at the level of the eye. 4 A horizontal line at the level of the eye appears hori- zontal, and a horizontal plane at this level appears a hori- zontal line. /(j The vanishing-point of any set of parallel lines is in a parallel to them passing through the eye. Hence, to see the vanishing-point of any lines, we must look in their direction. f~ Of two parallel and equal lines which are foreshortened, the nearer may appear the shorter. /^ Of two equal lines which are perpendicular to each other and have one end common, the one at the greater angle with the picture plane appears the shorter, and vanishes at the greater angle. PERSPECTIl'E PRINCIPLES. 133 If one side of a square vanishes toward the left, the other side vanishes toward the right. When the sides of a square make equal angles with the picture plane, they appear of equal lengths, and the " angles of inclination and convergence " are equal. /f The " angle of inclination " of any retreating line depends upon the level of the eye and its distance from the line, but it is always much less than the real angle that the line makes with the picture. / The convergence of parallel lines is in the direction of their farther ends. These are points of the invisible faces of any right square prism. i*f If both ends of any edge are points of invisible faces, the edge must be considered as " not foreshortened," even if its ends are unequally distant from the eye. y Straight lines must generally be represented by straight lines, and vertical lines by verticals. If two of the vertical sides of a cube or prism are seen, ' both sets of horizontal lines appear to converge. When one diagonal of a horizontal square appears a vertical line, the other appears a horizontal line, and the sides vanish equally in each direction. ^/ When the pyramid is vertical, its vertex is in a vertical line through the centre of the base. & 2- The vertex of an isosceles or equilateral triangle is in a perpendicular to the base at its centre. ^ ^ The diameters and diagonals of the regular hexagon 134 FKEE-HAXD DRAWING. divide the diagonal which they intersect into four equal parts. The circle generally appears a circle, a straight line, or an ellipse. A horizontal circle, above or below the level of the eye, appears a horizontal ellipse. The centre of the circle does not appear the centre of the ellipse, and the long axis of the ellipse is not a diameter of the circle. The foreshortened vertical circle, when above or below the level of the eye, appears an ellipse whose long axis is not a vertical line. j & The long axis of the ellipse appears perpendicular to a line which is at right angles to the circle at its centre. o d Only one end of a cylinder can appear a straight line at one time. The other end appears an ellipse. 3d If any of the curved surface of the cylinder with an end is seen, the end does not appear a circle. ?/ If the visible end appears an ellipse, the invisible end appears an ellipse proportionally wider than the visible end. o ^ The long axes of the ellipses are perpendicular to the axis of the cylinder. ? 3 Any part of the convex surface of the cone may be seen at one time. When the cone is vertical and below the eye, more than half is visible ; when above the eye, less than half. PERSPECTIVE PRINCIPLES. 135 ty When the base appears an ellipse, its long axis appears perpendicular to the axis of the cone. 2j- The contour elements of the cylinder and cone appear tangent to the ellipses of the bases. In the cylinder, the tangent points are frequently not in the axis of the ellipse. In the cone, they are never in the axis. I/ The apparent distance, measured on the short axis, between the ellipses representing concentric circles is the same perspective part of the short axis that the dis- tance between the ellipses, measured on the long axis, is of the entire long axis. 3** The lines which represent a foreshortened vertical * ring are nearly parallel to an ellipse which represents its centre line. They are not ellipses. a - The angles of two polygons, whose centres coincide, and whose sides are parallel, are in the same diagonal lines. o An angle may appear of any size, large or small, 7 according to whether the sides or the plane of the sides is foreshortened. The above are most of the points essential to the draughtsman; and those not teachers, and those unable to follow all the chapter, and those not interested in the subject for itself, may find that the review includes nearly all that they need. CHAPTER VII. QUESTIONS FOR EXAMINATIONS. To be answered by drawings, supplemented, if necessary, by writing. Unless otherwise stated, all drawings are to be Model Drawings. 1. Illustrate by diagrams representing the eye, the picture plane, and a sphere, the different positions of the picture plane which produce " true " and distorted pictures. 2. How do parallel retreating lines appear? Illus- trate by a cube all of whose lines appear to converge. Show by arrows the directions in which the lines vanish. 3. Illustrate by sketch of a cube the way parallel, retreating horizontal lines appear. 4. Represent a horizontal square plane, whose sides extend to the left at 30, and to the right at 60, when the plane is on the level of the eye. 5. In any background, how is the position found of the point where parallel lines appear to vanish? Illus- trate by sketch of any room, with a box upon the floor, and write any points which the sketch may not make dear. 6. How do vertical lines above the eye appear, and how should they be represented ? Illustrate by sketches of a cube. 136 QUESTIONS FOR EXAMINATIONS. 137 7. Make a sketch of a cylinder or a square prism, which shall show that the more distant of two parallel and equal lines may appear the longer. Mark the nearer line AB, the farther CD. 8. The " angles of inclination " of the lower visible edges of a cube which is below the eye, and rests on a face on the floor are equal. Represent the cube. 9. How do parallel straight lines in Nature appear? Illustrate by representing the actual appearance of each of three cubes, placed first, in a straight line upon the floor ; second, in a vertical line, one being on the floor, another on the level of the eye, and the last above this level. 10. By sketches of the three cubes in the above positions, show how straight lines should generally be represented. T i . Give the actual appearance of a horizontal cylin- der whose length is 2, diameter i, 1 when below the eye, and so placed that the left-hand base appears a vertical line. 12. Show by a sketch of an interior when this appear- ance would be the best drawing of the cylinder. 13. As a representation of simply the cylinder, what drawing is better than the actual appearance? 14. Represent a cube above the eye, with four edges vertical, when three of its sides are visible as surfaces. 1 The cylinder may be drawn of any size but of these proportions, and the same for following problems. 138 FREE-HAND DRAWING. 15. The same cube when a diagonal of its visible horizontal face appears a vertical line ; and a vertical square prism, whose length is 3, diameter i, having upon it a square pyramid whose base is 2, axis 2. The axes of the solids coincide, and the edges of the bases are parallel. The lower base of prism on level of eye. 1 6. Above solids when the eye is on the level of the centre of the prism, and a face of this object is "not foreshortened." 17. The same solids and conditions, except that two faces of the prism are seen equally. 1 8. A prism whose ends are equilateral triangles whose sides are half as long as the prism, rests upon a face upon the floor below the eye. The sides of the face on the ground extend to right and left at equal angles with the picture. The left base is visible. Show all tests of the drawing, and the directions in which all the lines vanish. 19. The same when the object is above the eye. 20. The same object when above the eye, and the ends of its horizontal face are " not foreshortened." 21. A regular hexagonal card, horizontal and above the eye, with one diagonal " not foreshortened." 22. The same card vertical and on the level of the eye, and vanishing to the right. Its diameters are " not foreshortened." 23. The prism shown in Fig. 55, when it is horizontal and above the eye. QUESTIONS FOR EXAMINATIONS. 139 24. The same when it is below the eye, and horizon- tal, with its long edges "not foreshortened." 25. The pyramid of Fig. 56 when it is above the eye, with the diameters of its base "not foreshortened." 26. Place under the pyramid (Fig. 56) a cube, one diagonal of its top coinciding with the marked diagonal of the base of the pyramid. The square is to be larger than the hexagon. 27. Represent when below the eye a horizontal hex- agonal plinth, a square pyramid placed upon its top, and a hexagonal pyramid resting obliquely upon the floor and the plinth. 28. A cube with inscribed circles tangent to each square, when below the eye with first, two surfaces visible ; and second, three surfaces visible. 29. Show by a horizontal circle above the eye that the centre of the circle is not represented by the centre of the ellipse. 30. The long axis of the ellipse is what line of the circle ? 31. How do equal spaces on any retreating line appear? Illustrate by an "elevation." 32. A horizontal circle is seen by several persons who are the same distance above, and away from the circle. Does the same line of the circle appear to the different observers the long axis of the ellipse? Illustrate by a " plan." 140 FREE-HAND DRAWIXG. 33. Sketch a spinning-wheel which is below the level of the eye. 34. A vertical cylinder whose visible end is above the level of the eye. 35. A horizontal cylinder on the level of the eye, the cylinder " not foreshortened." 36. Why do not the long axes of the ellipses in Fig. 68 vanish? 37. Represent a horizontal retreating cylinder above the level of the eye, and so situated that its axis appears a vertical line. 38. A parallel cylinder on the same level and to the right of the last object, the ends of the cylinders in the same planes. 39. The retreating vertical side of a building which has in it three semicircular arches in the same vertical line, the eye on the level of the centre of the central arch. (See Fig. 64.) 40. A vertical cylinder, diameter i, length 2, with a cone upon it, the bases coinciding ; eye on level of the centre of the cylinder. 41. A horizontal circle is represented by an ellipse, whose long axis is 4" long, whose short is i" long. A concentric smaller circle appears an ellipse which inter- sects the long axis of the outer at points |" from its ends. 42. Represent a horizontal retreating pipe below the QUESTIONS FOR EXAMINATIONS. 141 level of the eye Its inner diameter half of its outside diameter. 43. A horizontal cylinder, diameter i, length 2, its axis on the level of the eye, and extending to the right at an angle of 45 with the picture, and a second equal cylinder just below, its ends in the same planes as those of the upper. 44. A vertical cone, resting upon the centre of a horizontal square plinth whose vertical sides are seen unequally, and a circular ring square in section, resting obliquely against the plinth. 45. The pyramid of Fig. 77 when above the level of the eye. 46. The same for the cone of Fig. 80. 47. A conical pail, of which the curved outer surface with the inner surface of the bottom is visible. 48. A cuspidore of double cone form when below the eye. 49. The double cone of Fig. 83 when it is horizontal, below the eye, and at a large angle with the picture plane. 50. The ring of Fig. 85 when it is vertical, and on the level of the eye, and more foreshortened than in the figure. 51. The frame of Fig. 88 when the axis of the ellipse representing the tangent circle is parallel to a side, as B. 52. The same when the axis is parallel to a diagonal of the square. 142 FREE-HAND OR A \VI.\G. 53. A triangular frame when it is horizontal and below the eye, with the most distant sides of the trian- gles " not foreshortened." 54. A vertical, foreshortened hexagonal frame below the eye. 55. A table with a square top and inclined legs. 56. A vertical cylinder below the eye, with a mould- ing half round in section at the top, one square in sec- tion at the bottom, and a groove square in section cut in the centre of the cylinder. Diameter of cylinder i, length 2. Width of bands |. 57. The vase of Fig. 92 when seen from below. 58. The same when seen from above, and very near so that the ellipses are wide. 59. The vase of Fig. 96 when the bottom is visible. 6b. The same for Fig. 98. 61. The same for Fig. 102. 62. Sketch an interior representing the floor and two walls, with a table or other objects. 63. The same, showing in addition the ceiling, or horizontal objects above the eye. 64. Sketch an interior representing three walls and furniture. 65. An interior representing one wall, with objects parallel to the wall, and on each side of the spectator. 66. The same when spectator is near an end of the wall. QUEST fONS FOR EX.-l ML\ T . I 77O.YS. 143 The following questions are for those who understand Orthographic Projection and Scientific Perspection. 1 67. Illustrate the difference in appearance between a perspective drawing of a cube placed at the left, below the eye, and with one face parallel to the picture plane, and a model drawing of the same. 68. The same for a cone at the right and vertical. 69. The same for a horizontal cylinder parallel to the picture plane, and its right base visible. 70. Make a perspective drawing of a horizontal square, which shall show that the perspective of a retreating line may be longer than the line. Make a model drawing of the same square. 71. Illustrate by means of the perspectives of a sphere the distortion found in a Plane Perspective representing objects above, below, or to the left or the right of the point opposite the eye. State briefly the difference between a Perspective and a Model Drawing. 72. Represent the objects shown by Figs. 104 and 105 when they are seen from the right instead of from the left. 1 An illustrated pamphlet comparing Plane Perspective and Model Drawing will be mailed on receipt of fifteen cents, to those teachers who wish more on this subject than this book contains. /Vf rfuu t\ & /f- m * N) H m ri tp <""> CD ^ f "\ / \ f ^ 1 \ 10 X. C/j s * v^ ^^ v|y J \ } V j r 7 /'J X -VO PLATE KM III. FIG. 77 F/G.79 F/c. 80 8/-S-. H m X X LJ Co Qo -I m X X PLATE XXII. F/G-.9Q (&e**Hon) 01 H o v. .' _---, ^ t- ~' SUGGESTIONS FOR FIRST LESSONS IN THE PUBLIC SCHOOLS. [These objects and similar ones should be studied in different positions until they can be well and easily drawn.] Square Card. Circular Card. Square Card. Triangular Card. L \ Square Card. Rectangular Card. Rectangular C?.-d. Rectangular Card. Triangular Card. Hexagonal Card. Hexagonal Card. Triangular Card. Horizonla! and Vertical Squares. Horizontal Squares. Vertical Squares. Horizontal Circles. Vertical Triangles. (E 7 THE LIBRARY UNIVERSITY OF CALIFORNIA Santa Barbara THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW. MAY 3 1989 1989 H Series 9482 A 000 647 340 9