359 
 <8 
 apy 1 
 
 FREE HAND DRAWING 
 
 BY 
 
 MAX KUSHLAN 
 
 THE BRANCH PUBLISHING COMPANY 
 
Free Hand Drawing 
 
 and 
 
 Designing 
 
 BY 
 MAX KUSHLAN 
 
 S. B. Assoc, W,S. E. 
 
 Author of 
 
 Practtcai, Physics 
 
 CHICAGO 
 
 THE BRANCH PUBLISHING COMPANY 
 
 1919 
 
<4f 
 
 COPYRIGHT, 1919 
 
 BY 
 
 JOSEPH G. BRANCH 
 
 ©CI.A529212 
 
 ^\cm 
 
 •>vO 
 
TABLE OF CONTENTS 
 
 CHAPTER PAGE 
 
 I Straight lyines 1 
 
 II Curved Lines 8 
 
 III Geometrical Bodies 16 
 
 IV Perspective Drawing 23 
 
 V Technical Illustrations 29 
 
 VI Technical Sketching 38 
 
 AND 
 
 ENGINEERING DRAWING 
 
 BY 
 
 JOSEPH G. BRANCH 
 
FREE HAND DRAWING 
 
 CHAPTER I. 
 
 One of the greatest requirements of the modern en- 
 gineer is to be able to make rapid neat sketches free- 
 hand, i. e. without the use of any drafting instruments, 
 but simply' by employing a well sharpened soft pencil 
 and an eraser. There are many cases in the daily prac- 
 tice of every engineer from the lowest to the highest 
 ranks, when they are called upon to make a free-hand 
 sketch of a job, and in some cases this rough sketch 
 remains later the only available record of the condi- 
 tion of the job before any changes took place. It is 
 therefore important to have such sketches done as 
 neatly and accurately as possible so that they would 
 convey the correct idea to the draftsman or to the man 
 who is to carry out the particular work represented 
 by such sketches. 
 
 There are two principal kinds of sketches employed 
 in describing engineering work: the actual picture of 
 the job, as it appears to the eye; and the ortho- 
 graphic projection of the object in the three principal 
 planes, but drawn roughly without the aid of instru- 
 ments and not to correct scale. We will endeavor in 
 the following chapters to cover the principles of both 
 types of sketching, beginning with the simplest ob- 
 jects first and then leading up to the free-hand draw- 
 ing of more or less complicated parts of machinery. 
 The text will be amply illustrated by suitable figures 
 which are the actual reproduction of a complete course 
 in free-hand drawing given in one of the leading tech- 
 nical schools in this country, and the readers are ad- 
 vised to follow up the exercises in the order suggested 
 
FREE HAND DRAWING 
 PLATE 1. 
 
 5* ^ 
 
 f-ij.i Horizon f of /./nQ 
 
 
 O 
 W 
 
 V 
 
 t 
 ± 
 
 B 
 
 F,y 3 45° Line 
 
 fi\ 
 
 'i 4 
 
 
 \ 
 
 f^'9. ^ - 
 
 E^l^q/ Oiy/iton o^ ^//7e 
 
 % \ / 
 
 •IB 
 
 ^^1 
 
 /vj^ ^' P/^o/^of-Z/o^ct/ Oiy-,'s/ofi ^ ^//7e 
 
FREE HAND DRAWING 3 
 
 in this course, so as to get the full benefit of the work. 
 Each figure must be thoroughly mastered before the 
 ntxit one is attempted as they gradually lead from one 
 to the other. 
 
 The first thing to learn about free-hand drawing is 
 the correct method of looking at things. The eye must 
 be trained to observe the size, shape and position of 
 an object and its relation to the other objects around 
 it. We must also be able to estimate distances and 
 angles, not necessarily their correct values, but as they 
 appear to our eye, which is usually out of proportion 
 with the actual dimensions of the object. Before we 
 learn to use the pencil we must therefore first learn to 
 use our eyes and get the general habit of observation. 
 It is a good plan to exercise in estimating sizes and 
 distances of various simple objects such as tables, win- 
 dows, books, wheels, etc. and then check these esti- 
 mates with the correct dimensions as found by the 
 foot-rule. It is surprising how such simple exercises 
 help to train the eye until the student can tell the size 
 and distance of an object within a small fraction of 
 the actual value. 
 
 Then the hand must be trained to a steady motion 
 of the pencil by supporting it slightly with the small 
 finger and moving it steadily in the direction desired. 
 The student should avoid from the very start, the prac- 
 tice of short, jerky movements of the pencil, indicat- 
 ing that the hand is undecided to proceed with the 
 line required. This usually gives a ragged line and 
 leads to a great waste of time in trying to keep the 
 proper alignment. The best method is to keep up a slow 
 but steady motion, using the eye to guide the hand in 
 the proper direction and then correcting with the 
 rubber. The first line should be drawn faintly, then 
 it should be corrected by touching up the various 
 points that appear to be out of the proper direction, 
 and then the line is to be strengthened by applying a 
 
FREE HAND DRAWING 
 PLATE 2. 
 
 ^Jj 6 - Rectfkn^fe 
 
 f:/<f 7, i^^Qi-e 
 
 ^f'sS- BjJM^hQl Tfi^hj/e 
 
FREE HAND DRAWING 5 
 
 slight pressure on the pencil, so that the result is a 
 smooth even line of uniform thickness. No instru- 
 ments should be used except once in a great while for 
 checking the work already drawn free-hand, and then 
 the corrections should never be made by the aid of 
 these instrument, but the work should be gone over 
 free-hand until it checks very closely with the instru- 
 ments. 
 
 Referring to Plate I, Fig. 1 is the first and the 
 most important element of freehand drawing, namely 
 the horizontal straight line. 
 
 This line should always be drawn from left to right, 
 as indicated by the arrow, and the students must 
 keep up this exercise until they are convinced that 
 they can draw it perfectly without spending much 
 time. It is advisable to check each line with a 
 straight edge, after it is completed, and then to try 
 to improve on it when drawing the next one. 
 
 Fig. 2 is the vertical line drawn downward in the 
 direction of the arrow. In this exercise the hand 
 should be held in the same position as when using a 
 knife in cutting a sheet of paper in the same direc- 
 tion. It is a good idea to locate a few points or short 
 dashes along the line before the line itself is drawn. 
 
 In Fig. 3 a straight line is drawn in a direction of 
 45 degrees from the horizontal. In order to accom- 
 plish this the eye must be trained to estimate the an- 
 gles between the line and the horizontal and vertical 
 directions and to keep these angles as nearly equal as 
 practicable. 
 
 The exercise shown in Fig. 4 and 5 is to train the 
 eye and hand to estimating divisions of a line. If the 
 number of divisions are even, it is a good plan to be- 
 gin by dividing the line into two equal portions, and 
 when that Is accomplished, divide each half in the 
 same manner. , In dividing a line into 5 equal parts, 
 lay off a mark at a point between the second and 
 
6 FREE HAND DRAWING 
 
 third portion, then divide the first part in halves, and 
 the second part into three equal parts. If a line is to 
 be divided in a certain proportion as indicated in Fig. 
 5, divide the line into as many equal portions as are 
 contained in the sum of the two numbers of the pro- 
 portion required. Thus if a line is to be divided in 
 the ration of 5 to 7, lay off 12 equal parts, and then 
 take 5 parts for the first portion, and 7 parts for the 
 second portion. 
 
 This set of exercises must be thoroughly finished 
 in every detail so that the eye and the hand w^ork in 
 harmony and the lines and their divisions are correct 
 within 5 per cent at least, before any attempt is made 
 to take up the work of the next plate. 
 
 The next step is to draw a correct rectangle, as 
 shown in Fig. 6, Plate II, where the proper shading 
 is added to give a better effect. The horizontal lines 
 are drawn first as nearly parallel as could be done. 
 Then one vertical line is drawn at right angles to the 
 first two, and equal spaces are laid off on each hori- 
 zontal line from their points of intersection with the 
 vertical line; these points are connected by another 
 vertical line, guiding it so that it is at right angles 
 to the two horizontal sides and is parallel to the other 
 vertical side. 
 
 In drawing a square, as shown in Fig. 7, care 
 should be taken to lay off the horizontal spaces equal 
 to the vertical distance between the lines, since to 
 the eye vertical lines always appear longer than hori- 
 zontal lines of the same size, and the sides should be 
 carefully checked by means of instruments until the 
 student acquires the proper training in allowing for 
 this optical illusion. 
 
 The equlateral (equal-sided) triangle is drawn by 
 first laying out a horizontal axis A B (see Fig 8, 
 Plate II) and dividing line A B into halves at point 
 D, and from D draw a vertical line at right angles to 
 
FREE HAND DRAV/ING 7 
 
 A B. Try to locate on this vertical line a point C 
 such that when connecting points A and B with point 
 C. we will have lines AC and BC equal to AB. This 
 will be rather difficult at first, but after a few trials 
 the student will be able to find the correct point with- 
 out any trouble. The lengths of the sides of the tri- 
 angle can be checked roughly by making use of the 
 pencil in laying off with the fingernail the size of 
 AB from the end of the pencil then comparing this 
 with the other two sides, carrying the pencil with 
 the marking finger around to the different lines to be* 
 measured. This furnishes a rough method for check- 
 ing lengths and is frequently used by engineers in 
 making sketches on the job. When the triangle is 
 drawn correctly then the other two equal sides AC 
 and BC (see Fig. 8) should be divided in halves, and 
 each middle point should be connected with its op- 
 posite vertex. The three lines drawn in such a man- 
 ner from the vertices should meet in one common 
 point as shown in the figure, making the whole 
 arrangement perfectly symmetrical. 
 
CHAPTER IL 
 
 Curved Lines. 
 
 The ability to draw curved lines correctly seems 
 at first to be a good deal more difficult than the 
 straight-line work on rectilinear figures. This opin- 
 ipn is, however, very far from the truth ; in fact, after 
 a few trials the student will find that it is just the 
 reverse : it is a good deal easier to draw curved lines, 
 since our hand is more nearly adapted for a sweeping 
 motion along a curved path, and in drawing a straight 
 line we are^ constantly deviating from a curve by a 
 strong exertion of our will. A good deal of the suc- 
 cess in beginning the practice with curved lines de- 
 pends upon the confidence of the student in his ability. 
 to get good results; this will always produce a 
 smoother curve due to the free and easy sweep of the 
 determined hand, and will prevent a good deal of 
 waste of time and energy at the very start. 
 
 There are many ways of drawing a circle correctly 
 without the aid of a compass, some of them being 
 rather crude and primitive; but all of these methods 
 are helpful in certain cases, and we will mention them 
 all, leaving it to the student's judgment to decide 
 which would be the best to use on different occasions. 
 
 Everyone is familiar with the method of drawing 
 circles by the help of some round object on hand, 
 such as a coin of suitable size, a plate, or any round 
 disk having a smooth edge. The disk is held firmly 
 down on the paper with the left hand, the tips of the 
 fingers being supported at a point near the center, 
 and the pencil is held vertically in the right hand, 
 which traces the circle, beginning from the top in a 
 clockvv^ise direction, care being taken not to incline 
 
FREE HAND DRAWING 
 
 the pencil so as to distort the curve and not to move 
 the disk from its initial position. When the right 
 hand reaches the part of the circle to the extreme 
 
 A^. 9lCy^c/e 
 
 left, then it is not advisable to try to finish the curve 
 beyond the left arm, but it is much easier to change 
 the position of the right hand to a point in front of the 
 left arm and then resume the curve until the starting 
 point is reached. The main disadvantages of this 
 
10 FREE HAND DRAWING 
 
 method are the necessity of having a round object on 
 hand of a size suitable for the circle to be drawn, and 
 at best such a circle will not appear very smooth, 
 due to the necessity of tracing it from point to point, 
 and thus losing the correct direction of the curve in 
 that process. Its advantages are the simplicity and 
 saving in time, especially where only rough sketching 
 is required. 
 
 For circles of a relatively larger size, from 2 to 5 
 inches in diameter, we can use the method of turning 
 the paper about a point fixed by the right index finger, 
 provided the paper is free to move and is not too 
 large to make its motion clumsy or uneven. The 
 pencil is firmly grasped between the right thumb and 
 the forefinger, and the index is extended pressing the 
 paper as a fixed pivot, about which the paper is slowly 
 turned from right to left, or in a counterclockwise 
 direction. The pencil resting lightly against the re- 
 volving paper will describe a nearly perfect circle if 
 the fingers are held in place during the complete rev- 
 olution of the paper. 
 
 It is evident that this is a very crude method, de- 
 pending upon many unreliable factors, but it has the 
 advantage of not requiring any special tools except 
 a pencil and a piece of paper. 
 
 Another way for drawing a little more perfect circle 
 is to deliberately sweep the pencil in a clockwise di- 
 rection describing a closed curve approaching a circle 
 as nearly as possible, and then gradually smooth- 
 ing out and correcting those portions of the curve 
 that seem to be defective, until a nearly correct circle 
 is drawn. 
 
 This method requires some skill and a determined, 
 swift movement of the hand, which could be acquired 
 only by long and patient training of the hand and the 
 eye. The main advantages of this method are the 
 good results that are usually obtained, producing a 
 
FREE HAND DRAWING 
 
 11 
 
 fi^n Cy/mJer^ 
 
 FiS^ /2 /^ect(xn^u /ah So/icf 
 
 /t^, /3 -Pyt-oinjfcf 
 
1^ FREE HAND DRAWING 
 
 smooth and almost perfect circle, and its independ- 
 ence of any variable conditions that would tend to 
 distort the directions of the curve. 
 
 The most scientific way of drawing a circle is out- 
 lined in Fig. 9, where we first draw two axes at right 
 angles to one another; then the length of the radius 
 of the circle is laid off as equal distances from the 
 point of intersection of the axes in the four direc- 
 tions. It might be of help to draw two more lines at 
 45 degrees to the first ones, intersecting at the same 
 point, and to lay off the length of the radius upon all 
 these lines. The spacing is estimated by the eye and 
 can be done very accurately after a few trials. Then 
 the points thus laid off are connected with a smooth 
 circular curve, and the whole circle is corrected so 
 as to make as perfect a curve as could possibly be 
 obtained without the use of instruments. The free 
 use of the eraser is strongly advised for this work. 
 
 In order to draw the ellipse we must first know the 
 properties of that curve, so as to be able to check our 
 work with the correct curve. The two axes at right 
 angles to one another, as shown in Fig. 10, are the 
 principal lines of the curve. The longer axis, which 
 in this case is drawn horizontally, is termed the major 
 axis of the ellipse, and the shorter vertical axis is 
 known as the minor axis. If from the upper extrem- 
 ity of the minor axis we are to lay off accurately the 
 length of "I of the major axis, swinging this arc until 
 it strikes the horizontal line, we will thus obtain two 
 points on the horizontal line, inside of the ends of the 
 major axis. These two points are called the foci 
 of the ellipse. The correct ellipse is then to be 
 constructed in such a manner that the sum of the 
 distances from any point on the curve to the foci 
 is equal in length to the major axis. This prin- 
 ciple could be used for checking the freehand curve 
 by means of a compass, until the student is able to 
 
FREE HAND DRAWING 
 
 13 
 
 draw the ellipse correctly. In drawing the ellipse 
 without the aid of any instruments we lay off the 
 major and minor axes accurately, estimating the 
 lengths so as to make the figure perfectly symmetri- 
 cal. This gives us four points on the curve, and these 
 are then connected with the smooth curve, checking 
 the outline by the eye until we obtain the correct 
 elliptical shape. It might be of help to bear in mind 
 that the portions of the ellipse near the extremities 
 
 
 FIG 14. 
 
 of the major axes are very nearly circular, while the 
 portions near the extremities of the minor axes are 
 nearly straight lines. 
 
14 FREE HAND DRAWING 
 
 Drawing From Models. 
 
 The principles outlined above will enable the stu- 
 dent to make neat sketches of simple solid bodies, 
 such as cylinders, rectangular solids, cubes, pyramids, 
 cones, etc. In order to learn the appearance of these 
 geometrical bodies from different angles it is advis- 
 able to obtain some simple models of these bodies 
 and devote some time in copying them in different 
 positions and from different angles. At first it is 
 advisable to draw these solids in their normal posi- 
 tions, such as indicated by the Fig. 11, which is a 
 freehand sketch of the cylinder. Fig. 12 being a view 
 of the rectangular or oblong solid, and Fig. 13, which 
 is a side view of a square pyramid. Especial attention 
 should be given in shading the sides of these figures 
 by either carefully noting their actual appearance in 
 life, or by imagining a ray of light illuminating them 
 at a certain angle. 
 
 Referring to Fig. 11, it is important to remember 
 that the top and bottom of the cylinder, although cir- 
 cular in shape, appear to the eye as elliptical, so that 
 in this case the top is drawn as a complete ellipse, 
 having its major axis equal to the actual diameter, 
 while the minor axis is made shorter, the amount of 
 shortening depending upon the relative position 
 of the observer and the body. The bottom is drawn 
 as a half of an ellipse, equal in size to the one at the 
 top. The light is assumed to come from the lower 
 right hand corner, so that the left portion of the fig- 
 ure is shaded, the degree of shading varying from 
 heavy to light as we proceed towards the right. 
 
 In Fig. 12, representing the rectangular solid, care 
 should be taken to make all the edges as near parallel 
 as practicable. In Fig. 13 the pyramid is placed in 
 such a position that only two of its triangular sides 
 
FREE HAND DRAWING 15 
 
 are in view, the slope of the lines at the bottom de- 
 pending upon the angle at which the observer is 
 placed in relation to the body. 
 
 Fig. 14 is a combination of a cylinder (upright), 
 and on the left a square pyramid lying flat on one of 
 its sides, with its bottom exposed to view, and its top 
 hidden behind the cylinder, and to the right we have 
 a cube partially hidden behind the right edge of the 
 cylinder. The student is advised to make this exer- 
 cise by arranging the models in the same manner and 
 drawing the figure without referring to the illustra- 
 tion here shown, then comparing the result with Fig. 
 14. Then the models are to be rem.oved and the same 
 arrangement is to be drawn from mem.ory, including 
 the shading. This will enable the student to grasp 
 the idea of the true representation of objects as they 
 appear to our eye, and will lay the foundation for the 
 more advanced free hand sketching, either from life 
 or from memory. It might be advisable to mention 
 here that the beginner is warned to proceed with the 
 above exercises very slowly and in their logical order 
 outlined above, being careful not to begin the work 
 of any new figure until the preceding exercise has 
 been thoroughly mastered in every detail. 
 
CHAPTER III. 
 
 Geometrical Bodies. 
 
 The representation of geometrical bodies in space 
 requires a good deal of skill which could be acquired 
 only after a systematic course of study based upon 
 careful observation of the appearance of objects in 
 nature. As suggested in the previous chapter, the 
 student is strongly advised to make use of constructed 
 models in going over the following exercises. By 
 rearranging these bodies in various positions with 
 respect to one another and to the horizontal plane, we 
 can produce as many combinations as we desire, thus 
 making a practical study of the actual appearance of 
 these bodies from different angles and with different 
 shadings. 
 
 Referring to the group of bodies shown in Fig. 15, 
 we have here three geometrical bodies: — a cube, a 
 cylinder and a triangular prism. The cylinder is 
 shown standing upright with the cube tilted and lean- 
 ing against the back part of the cylinder, towards the 
 left, and the prism is shown in front of the cylinder 
 lying flat on one of its sides at an angle, and one of 
 its edges just touching the forward portion of the 
 cylinder. 
 
 In order to draw this position correctly with the 
 least trouble, it is advisable to begin with the cylinder, 
 since this is the central figure in the group. First 
 draw the top of the cylinder as an ellipse, determining 
 the correct ratio between the major and minor axes 
 by the eye, remembering that the major axis (hori- 
 zontal axis) is equal to the correct diameter of the 
 circular top, while the vertical axis is the one that is 
 
FREE HAND DRAWING 17 
 
 foreshortened. After sketching in very lightly the 
 four extremeties of these axes and the other principal 
 points on the curve, the ellipse is then drawn in 
 heavier lines, forming a smooth and symmetrical 
 curve. Then the edges of the cylinder are drawn as 
 plain vertical lines, and both the top and the lateral 
 surfaces are shaded towards the left, since the light in 
 this case is shining from the lower right hand corner 
 of the plate. (See Fig. 15). 
 
 The next step is to draw the prism, beginning with 
 the forward face in its correct relative position and 
 without any shading since the light is shining right 
 upon the surface. Then the face of the prism which 
 is away from us is shown as a rhomboid with one side 
 elongated and the other side shortened, since that 
 would be its natural appearance to our eye. That side 
 is shaded quite heavily, and its shadow is slightly indi- 
 cated falling upon the forward left portion of the 
 cylinder. 
 
 The outline of the prism is now completed by fin- 
 ishing the third side of the triangular end, which is 
 shaded towards the left due to its inclination to the 
 rays of light. 
 
 The cube which is partially covered by the cylinder 
 is then drawn, beginning with the face nearest to the 
 cylinder, this face receiving the shadow thrown upon 
 it by the cylinder. Then the bottom of the cube is 
 drawn with two of its edges parallel to the corres- 
 ponding edge upon the top of the front face, and the 
 left edge of the bottom making the proper angle with 
 these parallel edges. The bottom is heavily shaded, 
 and so is the space between this bottom and the cylin- 
 der since the rays of light do not reach into that por- 
 tion of the group. The outline of the cube is finished 
 by drawing the left face as a rectangle having all its 
 sides parallel to the corresponding edges of the other 
 
18 
 
 FREE HAND DRAWING 
 
 face that has already been drawn. The left face of the 
 cube is not shaded since it presents all of its surface 
 to the light. - 
 
 By carefully examining Fig. 15 the student will ob- 
 serve that the shading is made according to certain 
 definite principles which could easily be acquired by 
 following out each portion of the figure with reference 
 
 FIG. 15. 
 
 to the source of light. It is also clear that the propor- 
 tions of the bodies as shown in the drawing are very 
 much distorted from their actual measurements since 
 by observing an object from a certain angle we see 
 some lines longer and other lines shorter than they 
 actually exist in space. To illustrate this, let us 
 
FREE HAND DRAWING 19 
 
 imagine that we are looking at a straight line placed 
 vertically at a certain distance from us parellel with 
 the vertical axis of our body. We then see it as a 
 vertical line in its correct actual length. Now, if we 
 were to tilt this line forward or backward, we will get 
 the impression that this line is still vertical if we have 
 not moved it to the right or left, but the line will 
 appear to our eye a good deal shorter since due to the 
 tilting the upper end of the line is vertically nearer to 
 the lower end. By tilting the line more we see it 
 getting shorter and shorter, until when we get the line 
 in a position at right angles to our body, all we can 
 see is the point of its nearest end, and if we look 
 straight at the line we cannot tell whether it is a line 
 or a single point. 
 
 In the same manner we can look straight at a circle 
 placed with its plane parallel to our body, and then 
 we see it in its actual circular shape. But if we re- 
 volve the circle about its horizontal diameter, we will 
 get the impression of an ellipe, the major axis being 
 equal to the horizontal diameter, and the minor axis 
 being the vertical distance between its upper and 
 lower edges. It is evident that the more we tilt the 
 circle, the shorter will be the appearance of the ver- 
 tical axis of the ellipse ; and if the circle is placed with 
 its plane at right angles to our body, the circle will 
 then give us the impression of a straight line equal 
 in size to the diameter. 
 
 From the above illustrations it is evident that the 
 amount of distortion of an object as it appears to our 
 eye bears a direct relation to the angle at which we 
 observe it, and in each case the proper shortening or 
 lengthening of the lines can be correctly determined 
 by the analysis as outlined in the above two cases. 
 
 This process, however, is rather tedious and requires 
 a lot of valuable time, so that in this free-hand work 
 
20 
 
 FREE HAND DRAWING 
 
 the students are not expected to perform their work 
 in such a manner. 
 
 The easiest and quickest way is to get the proper 
 amount of distortion from practical experience with 
 models ; but the principles underlying the causes for 
 such distorted proportions should always be kept in 
 mind as a guide and a check to the practical execution 
 of the work. 
 
 FIG. 16. 
 
 Fig, 16, representing another arrangement of a cube, 
 a cylinder and a square pyramid, will furnish addi- 
 tional suggestions for arranging the models and for 
 proper shading. The students are advised here to 
 carefully distinguish between the shades and shadows 
 in these figures. By the shade of a body is meant the 
 darkened portion of the surface of the body due to the 
 more or less partial obstruction of that part from the 
 direct rays of light. By the shadow is meant the 
 darkness produced upon the surface of a body due to 
 
FREE HAND DRAWING 
 
 21 
 
 the obstruction from the rays of light by some other 
 body placed in their path. Thus, in Fig. 16, the upper 
 portion of the cylinder shows the shading, while the 
 
 Fia 17, 
 
 part near the bottom of the cylinder is the shadow cast 
 upon the ground and upon the cylinder by the pyra- 
 mid. Both the shades and shadows must be included 
 in any complete freehand sketch to make it appear 
 
22 FREE HAND DRAWING 
 
 more natural and true to the appearance of the same 
 bodies in life. 
 
 As an illustration of fine work in shades and 
 shadows we have the free-hand sketch in Fig. 17 
 showing the appearance of a cone, with two sections 
 made in it, one parallel to its vertical axis resulting in 
 the shape of a parabola, and the other section taken 
 at an angle between the horizontal and vertical planes, 
 giving the shape of a portion of an ellipse. The cone 
 is here represented standing upright upon a table, the 
 shadow of the cone falling to the right, partly upon 
 the back wall, and partly upon the surface of the table. 
 The source of light in this case seems to come from 
 the lower left hand corner, so that the shading of the 
 object, wall and portion of the table is heavier towards 
 the upper right hand portion of the sketch. Attention 
 is also called to the fact, that all the shading is done 
 here by straight lines varying in density and in direc- 
 tion according to the requirements, and the outline of 
 the objects being produced by the shade lines them- 
 selves meeting one another, as would be the case with 
 the appearance of objects in nature. Such shading is 
 very often made with the help of a straight edge, and 
 gives excellent results if the available time allows such 
 refinements. 
 
CHAPTER IV. 
 Perspective Drawing. 
 
 In order to represent objects exactly as they appear 
 to our observing eyes we must take into account the 
 peculiar optical illusion that distorts the proportions 
 of the bodies when placed at an appreciable distance 
 from the observer. In case the body is placed far 
 from the eye it appears a good deal smaller than it 
 actually is, the amount by which the size seems to be 
 diminished being directly proportional to the distance 
 between the object and the observer. Thus when a 
 train moves away from the observer, the last car 
 seems to get smaller as the train moves farther away, 
 and when the car is twice as far from the observer 
 than it was when he first looked at it, its size appears 
 about one half of what it seemed to be at the first ob- 
 servations. 
 
 By looking at a long object that stretches quite a 
 considerable distance directly in line of observation, 
 the front portions of that object will appear -a good 
 deal larger than the parts that are at the farther end. 
 Such is the common experience with views of long 
 buildings, streets, rows of trees, posts in line, and sim- 
 ilar objects that are made up of similar parts arranged 
 along definite straight lines. 
 
 To illustrate the simplest case of this effect we have 
 the sketch in Fig. 18 of a bookcase lying flat on the 
 floor, away from the observer who is looking down 
 upon it, but not directly over it. The front portion of 
 the bookcase nearest to the observer is drawn a good 
 deal larger than the rear end, and the sides are made 
 to slope gradually from the larger to the smaller rect- 
 
24 
 
 FREE HAND DRAWING 
 
 mm 
 
 I- 
 
 
 m 
 
I I I I I I I I I I I I 
 
 FREE HAND DRAWING 25 
 
 angular shape. Following the same idea, the distance 
 between the first shelf and the second one is shown 
 proportionally greater than the distance between the 
 second and the third shelf, etc. It is important to no- 
 tice the widths of these shelfs are drawn unequal, get- 
 ting gradually smaller as we go from the front view 
 to the rear. All the other portions of the bookcase 
 are drawn along the same lines which are not parallel 
 but all slope towards some imaginary common point 
 of intersection, which is known as the vanishing point 
 of the picture. By holding this sketch at a distance 
 from the eyes equal to about the length of the arm, 
 the reader will observe that the impression given by 
 this sketch is of an object having all its edges per- 
 fectly parallel, although by examining it more closely 
 we can see at once that they are far from being 
 parallel. Such a method of representing solid bodies 
 is known as Perspective drawing, and is used a great 
 deal in many cases by engineers, artisans, mechanics 
 and architects. 
 
 The correct methods used in representing a simple 
 object by means of perspective drawing is illustrated 
 by Fig. 19, which shows the outline of a house drawn 
 by the observer standing at the one of its corner at 
 some distance and a little above it so that he could 
 get the full view of the walls and the roof. In this 
 case use is made of two vanishing points, marked A 
 and B respectively. Each of these vanishing points is 
 used for each of the two walls visible to the observer, 
 since he gets two directions in which the lines of the 
 object seem to converge into single points if they were 
 continued far enough. All the parts of the building 
 are drawn in the same manner getting smaller and 
 nearer to one another as we go from the nearest cor- 
 ner to the far ends of the building. s 
 
 The sidewalks are represented in the same manner, 
 so that by looking at Fig. 19 at a distance we get the 
 
26 
 
 FREE HAND DRAWING 
 
FREE HAND DRAViJING 
 
 27 
 
 impression of the actual building as it appears to our 
 eyes under similar circumstances. 
 
 Fig. 20 illustrates the same principles of perspective 
 
 applied to an object having several curved lines as 
 well as straight edges. The portable blackboard 
 shown here has rounded corners at the bottom pieces 
 
28 FREE HAND DRAWING 
 
 of the supporting frame, also some rollers and 
 curved iron rods to support the brackets and to stiffen 
 the wooden frame. All these curves are drawn out of 
 actual proportion, but in the correct ratio of the dis- 
 tance of each point from the observer, the whole sys- 
 tem of lines converging towards the single vanishing 
 point A. This sketch is made still closer to actual ap- 
 pearance by the shading of some portions of the frame 
 and very light shading of the visible portion of the 
 board itself. 
 
 In drawing any object by the above method it is 
 best to observe closely the apparent angle which the 
 lines of the object make with one another, and then 
 lightly sketch in these outlines, changing them until 
 the correct vanishing point is finally located. Then 
 the main outlines are marked off along these vanish- 
 ing lines keeping all the vertical directions straight 
 up and down and parallel, since in ordinary cases the 
 vertical distances are not far enough to be represented 
 at a distorted angle. The distances along any of the 
 vanishing lines are then laid off in the proportion of 
 the location of the points from the observer, the larg- 
 est distance being directly in the front view, and the 
 smallest distance being the last one near the vanish- 
 ing point. This does not have to be made correct in 
 such proportion, since it is only important to produce 
 the general impression rather than make an exact 
 layout, which could only be accomplished by means 
 of drawing instruments and many computations. In 
 ordinary cases the sketch is laid out roughly, aided 
 only by the experience of the trained hand and the 
 judgment of the eye. 
 
i|i|i| |i|M'i'ri'i'i'i I I B I I 
 
 CHAPTER V. 
 
 Technical Illustrations. 
 
 In this course of free-hand drawing we have so far 
 presented all the important theoretical elements neces- 
 sary for the production of a correct sketch. Begin- 
 ning with the simple exercises of the straight lines 
 and elementary curves we have taken up the ques- 
 tions of drawing solid objects, the rules for shading 
 and the principal requirements for perspective draw- 
 ing. These exercises will enable the student to make 
 a neat and accurate sketch of a simple object. 
 
 We will now endeavor to take up the practical appli- 
 cations of the above principles so as to present a con- 
 cise course in technical free-hand work used for mak- 
 ing simple illustrations or rapid sketches of actual 
 pieces of machinery or apparatus, taken in the field 
 and used later for a more careful drawing to scale 
 by means of instruments. 
 
 In this work we can freely use the rule for making 
 straight lines, since in case of practical drawing of 
 this kind the straight edge is invariably used in one 
 form or another. 
 
 We will first discuss a few typical examples of more 
 or less elaborate free-hand drawings that are to be 
 used as technical illustrations rather than working 
 sketches; or, in other words, we will study how to 
 make a neat-looking free-hand drawing of some tech- 
 nical appliance to be used for illustrating^ a cata- 
 logue, an advertisement in a technical magazine or an 
 engineering paper of any kind without giving any 
 exact dimensions or details, but presenting z general 
 
30 
 
 FREE HA.sTD DRAWING 
 
 idea about the appearance or arrangement of the par- 
 ticular part that we wish to describe. 
 
 Such illustrations are often made purely from the 
 imacrination or by memory without the aid of any 
 TdeTs or drawings of .Ij kind^ But it - more 
 common and advisable to have either fe object or a 
 reduced model of the part to be illustrated in front 
 of the sketching pad, so that the drawing xs made 
 more accurate with the proper shading and the diflfer- 
 Sit portions of the objects shown m their cor ect 
 relative proportions. In case the object is not avail- 
 able or is tJo large, and a model is too expen^ve or 
 could not be obtained for any other reasons, the next 
 best thing to do is to make use of a photograph show- 
 ing severll views of the object to be represented. From 
 thlse photographs we can form .a clear idea of the 
 exact construction of the part in question and after 
 ehmLating all the "--P-t-t details and ou lining 
 the main features we can draw the object with its 
 essential details so as to bring out more forcibly ce;^- 
 tain parts which we wish to emphasize, and to elim- 
 inate all the features which are of secondary import- 
 ance and are liable to confuse the reader 
 
 Referring to Fig. 21, we have here a sketch of a 
 wooden pa^ttern ffr the main casting of. a dynamo- 
 machine. This is drawn from the full-sized pattern 
 Saced at such an angle that all the mam features of 
 fhe pattern are well illustrated such as the circular 
 rnagSec frame, the supporting plate, the two end 
 Seces and the poles attached to the intenor portion 
 S the frame. The drawing also shows the ocat - 
 of the lines of splitting the pattern both horizontally 
 and vertically, also the smaller details such as lugs, 
 
 'TSintoS'the above sketch we first determine 
 the axes of symmetry of the whole figure, which in 
 tWs case are the axes of the ellipse representing the 
 
FREE HAND DRAWING 
 
 31 
 
 outer edge of the circular frame. These Unes are 
 drawn in very light, the vertical axis being a vertical 
 line, but the horizontal axis drawn inclined lower to 
 the right, making an angle of 15°-20° to the horizontal 
 line. Then the width of the framing is lad off hori- 
 zontally at the top, and the two ellipses are drawn 
 in according to the methods outlined in the previous 
 
 FIG. 21. 
 PATTERN OF DYNAMO. 
 
 chapters. Only those portions of these ellipses are 
 shown that are actually visible, but the outline could 
 be made with ellipses complete in very light lines, 
 and then the portions that are visible are gone over 
 with firmer lines, while the invisible parts can be 
 erased. 
 
 The supporting plates (see Fig. 21) are then drawn 
 by means of the rule and pencil, care being take to 
 
Sa FREE HAND DRAWING 
 
 make the opposite edges nearly parallel or gradually 
 and very slightly converging towards the background 
 to give the correct perspective view. The end pieces 
 of the framing are next drawn making one edge of the 
 piece parallel to the corresponding edge of the sup- 
 porting plate, and the other edge, placed at an angle of 
 about 120° from the first one, which will give the im- 
 pression to the eye of a right angle. 
 
 In following up this sketch (Fig. 21) it is important 
 to note that all the main straight outlines are drawn 
 along three principal directions, one being exactly ver- 
 tical and the other two making an angle of 120° with 
 the first one. This method of representing objects 
 approaches very closely to the natural appearance of 
 any object to the eye and it is known as the Isometric 
 Projection. It is used a great deal in cabinet-making, 
 sheet-metal work and all similar cases where all the 
 three directions are represented in the same view. 
 
 The pole pieces in Fig. 21 are in each case drawn 
 at right angles to the interior of the framing, and 
 the drawing is then completed by adding the smaller 
 details and by proper shading so as to indicate the 
 light shining from the lower right-hand corner. We 
 must also consider here the shadows thrown by one 
 part of the machine upon the other, as well as the 
 shadows thrown by these parts upon the base of 
 support or the other objects in the Immediate vicinity. 
 Every portion of this sketch must be gone over care- 
 fully several times by the aid of the eraser and pen- 
 cil until each one is neat and accurate and the whole 
 drawing gives the correct impression of the appear- 
 ance of the machine. 
 
 Fig. 22 is a somewhat similar sketch of a special 
 electrical fitting Intended particularly as an Illustra- 
 tion for an advertisement showing the main points of 
 connections and a portion of the Interior arrangement 
 for contact. 
 
FREE HAND DRAWING 
 
 33 
 
 The main body of the fitting (see Fig. 22) is made 
 up of a cylindrical receptacle provided with circular 
 base having four projecting pieces attached to it for 
 support and also for making the necessary connections. 
 The top of the fitting being open and of circular shape 
 
 FIG. 22. 
 
 is indicated by means of two ellipses, the distance be- 
 tween these curves corresponding to the thickness of 
 the wall of the appliance. Inside of this hollow cylin- 
 der there is a portion of another ellipse shaded very 
 heavily to show the metal connection visible at that 
 point. 
 
34 FREE HAND DRAWING 
 
 Special stress is laid upon the connection lugs and 
 screws, since these form one of the features of advant- 
 age of this particular electrical specialty, and these are 
 shown very prominently and shaded with particular 
 care to bring out these parts clearly. The outline of 
 the base is made partly cylindrical and partly rectang- 
 ular according to the location of the particular part, 
 since the space between the four projecting pieces is 
 made up of arcs of a circle of a radius somewhat larger 
 than the outside radius of the top portion of the fit- 
 ting. 
 
 The shading in Fig. 22 is very simple, since the whole 
 figure is symmetrical about a common vertical axis, 
 and all the shade lines are practically all vertical. 
 
 The lamp drawn in Fig. 23 illustrates the method of 
 drawing an object entirely without any sharp outlines 
 but merely by the aid of shade and shadow lines. 
 
 For this sketch we have to make use of the pencil- 
 compass as well as of the straight edge, but any lines 
 drawn in that manner are used merely as guide lines 
 and are later erased in the course of shading, so that 
 the whole sketch when finished has no sharp lines 
 but very carefully drawn shade lines of varying 
 strength and spacing according to the amount of light 
 or shadow we wish to indicate at any particular point. 
 Such a method of free-hand drawing can be acquired 
 by the aid of frequent exercise with models and objects 
 placed at different positions with respect to an actual 
 source of light. 
 
 Another type of technical illustration used a great 
 deal for catalogues is shown in Fig. 24, which is a 
 rough sketch of a certain type of mast jib-crane show- 
 ing its general construction, method of support and its 
 relative position with respect to other objects. 
 
 The lines are drawn with the aid of a rule, and the 
 principles of isometric projection are employed here so 
 as to show the view of the steel members making up 
 
FREE HAND DRAWING 
 
 35 
 
 the framing and the appearance of its upper and lower 
 supports. The traveling trolley riding on top of the 
 channel frame is indicated by its circular wheels and a 
 few main lines of the casting that forms the carriage of 
 the trolley. The hoisting chain, block and hook are 
 indicated roughly, giving none of their details, but 
 presenting the appearance of the complete equipment 
 in a general way. 
 
 FIG. 23. 
 
 Such sketches are usually supplemented with notes 
 giving the names and the directions for each part of 
 the mechanism as well as the principal dimensions, so 
 that by the aid of such a rough free-hand sketch, we 
 have a clear idea as to the operation of the machine 
 
36 
 
 FREE HAND DRAWING 
 
 
 FIG. 24. 
 
FREE HAND DRAWING 37 
 
 and the* space it would require, giving us enough data 
 to enable us to make an exact working drawing of the 
 same machine, to scale. 
 
 The shading of this drawing is similar to those dis- 
 cussed above, including the shadow lines at the lower 
 support of the crane. 
 
 In all the above types of technical illustrations our 
 first object must be borne in mind, and that is to pre- 
 sent the sketch in such a manner that the reader can 
 get a clear idea of the general construction as well as 
 the appearance of the particular machine or equip- 
 ment which is illustrated so that the main features 
 could be grasped at once without requiring any long 
 description by means of text. An illustration of this 
 kind if neat and accurate will convey more information 
 at a glance than volumes of writing and it will be 
 found of great value to both the designing engineer 
 and the sales manager of the machine. 
 
CHAPTER VL 
 Technical Sketching. 
 
 The practical application of the principles of free- 
 hand drawing to purely engineering work is espe- 
 cially important in making rapid sketches of either 
 objects existing on a particular job to be investigated 
 or of work to be contemplated in the future. There 
 are many occasions in the daily experience of every 
 engineer or any man connected with engineering work 
 when he is called' upon to represent an object in its 
 correct relation to other things^ making a rough out- 
 line and giving all the necessary dimensions or other 
 notes of information. This is usually required to be 
 made in a short period of time under circumstance 
 which would not permit of the elaborate use of a 
 board, T-square or drawing instruments so that the 
 drawing is made absolutely free-hand, with only a 
 pencil and a scrap of paper, and with no means for 
 supporting the sketching paper except an occasional 
 back of a book or a wooden board. There are mo- 
 ments snatched v/hi\e traveling on the train when an 
 idea presents itself to the engineer about the job, 
 which he wishes to preserve at once for future de- 
 velopment. Then he has to use any chance scrap of 
 paper such as a back of an envelope and a stub of a 
 pencil to illustrate his idea with an accurate sketch, 
 which would be intelligible to himself and others when 
 the occasion arrives for making use of it. In all such 
 cases of emergency the modern engineer must train 
 himself to make these sketches rapidly, yet as neatly 
 and accurately as the occasion might require. 
 
 In the first place it is very important for every 
 technical man to have with him as part of his daily 
 
FREE HAND DRAWING 
 
 89 
 
 
 ,^^ 
 
40 FREE HAND DRAWING 
 
 equipment some kind of a memorandum book of a 
 size convenient to be carried in the pocket, yet suffi- 
 ciently large to allow enough space for notes and 
 sketches. A loose-leaf form is to be recommended 
 since the leaves can later be thrown away after they 
 have been copied in a more permanent form and they 
 can then be replaced by new ones at very small ex- 
 pence. 
 
 It is preferable to have at least part of this note- 
 book made of cross-section paper ordinarily used for 
 figuring, since these equal divisions wuU then serve 
 as a rough guide for straight lines and for the gen- 
 eral symmetry of the sketches, and this paper can 
 also be used to greater advantage in making compu- 
 tations. 
 
 The sketches can be made either representing the 
 objects as they actually appear to the eye as illus- 
 trated in the previous chapters, or we can make use 
 of the ordinary rules of projection^ which allows the 
 accurate representation of those views of the body 
 with which we are concerned leaving out all other de- 
 tails which would not add any information. 
 
 To illustrate some of the typical sketches made on 
 the job, let us examine the rough outline of a piping 
 connection shown in Fig. 25. At a glance we can 
 note that this pipe has two right-angular turns, one 
 from vertical to the right and then from the right to 
 the front. The first turn is accomplished by means 
 of a long-radius elbow, having a radius of 3 feet, and 
 the second turn is made by means of a standard elbow 
 its forward flange facing the observer and having 12 
 bolts spaced evenly around a 10|-inch bolt-circle. 
 These two elbows are connected by means of a 12- 
 foot-straight piece, and all the connections are made 
 by means of flanged joints bolted together. We have 
 here the main dimensions of these fittings, the size of 
 the pipe, its distance from a wall and the height of 
 
FREE HAND DRAWING 
 
 41 
 
42 FREE HAND DRAWING 
 
 the horizontal run above the first floor of the build- 
 ing. This amount of information seems to be suffi- 
 cient for building the whole portion of the piping, for 
 locating it correctly to scale on any drawing or for 
 reporting the condition as it exists to the man in the 
 office who is interested in that particular information. 
 Such a drawing is a correct picture of the appearance 
 of the piping as well as a projection drawing since it 
 is the front elevation of the pipe with its lower end 
 cut off and the front portion disconnected. Such a 
 sketch can easily be made in 5 or 10 minutes. The 
 usual procedure is first to draw the whole view of the 
 piping in the right proportion, not attempting to make 
 perfect lines or curves but using enough care so that 
 the general appearance conveys a clear idea of the 
 object. A little shading will greatly help the impres- 
 sion and should not be omitted in any of these sketch- 
 es. Then the measurements that would be required 
 are decided upon and the proper lines and arrow- 
 points are drawn in so as to be certain that none of 
 the measurement would accidentally be omitted. 
 Great care must be taken to place the arrow-points so 
 as to clearly indicate the points between which the 
 measurements are taken. Then the actual measure- 
 ments are made and are noted as fast as they are ob- 
 tained, none of them being kept in mind for any 
 length of time before being noted, thus avoiding the 
 chance of forgetting them or confusing them with 
 others. Each dimension should be carefully checked 
 by adding or substracting from some other point of 
 reference, such as a wall, column, etc. After all the 
 measurements are noted and checked, the whole job 
 must be given a thorough inspection and all informa- 
 tion relating to the purpose on hand should be clearly 
 covered by notes on the same sketch unless these 
 notes are so large as to require a separate page. 
 This rough and ready method of drawing is used 
 
FREE HAND DRAWING 43 
 
 not only for engineering objects that are already in 
 existence, but also for designing things that exist only 
 in the mind of the draftsman. This is done so as to 
 represent the idea rapidly in a more concrete form 
 before attempting to draw it to scale. Fig. 26 repre- 
 sents such a rough design of a cast iron Y-branch as 
 it appears to the draftsman before the actual detailed 
 drawing is made. It contained one full longitudinal 
 section of the fitting and a partial section showing all 
 the important features of the piece and giving only 
 the principal dimensions for preliminary computa- 
 tions. After these dimensions are checked and some- 
 what modified by computation, then the same piece 
 can be laid out to scale and it can be detailed to suit 
 the particular requirements. These preliminary 
 sketches are very valuable for future reference and 
 should be carefully filed for permanent record. In 
 Fig. 27 we have a case of structual detail where the 
 notes are more valuable than the dimensions, since 
 in this case the parts of the steel structure are made 
 of standard material and as long as the size of the 
 I-Beam angle or channel is noted we can easily find 
 all their other, dimensions or properties from any 
 handbook of structual steel shapes. The two im- 
 portant dimensions that would be essential in such 
 work are the horizintal spacing of the 12-inch I-beams 
 and height of the concrete slab above the top of the 
 beams. This sketch is not complete in itself since it 
 does not give the length and arrangement of the 
 above members in plain view or in horizontal plane, 
 but it is sufficient for the purpose of illustrating the 
 construction of a particular section of the building. 
 
 In making sketches of electrical wiring such as 
 shown in Fig. 28, we hardly need any dimensions, un- 
 der ordinary circumstances, except the size and loca- 
 tion of the switchboard panel. The purpose of this 
 sketch primarily is to show the relative location of 
 
u 
 
 FREE HAND DRAWING 
 
 
 ^-1 
 
 
 ^ 
 
 
 ^'^ 
 
 
 ^5< 
 
 >-l 
 
 of- 
 
 ^^ 
 
 .X 
 
 >^ 
 
 v^ 
 
 o 
 
 ot 
 
 00 
 
 
 "I 
 
 VVi 
 
 > 
 
 s 
 
 l> 
 
 
 
 L V 
 
 
 
 \^V^ 
 
 
 
 ^ 
 
 1 
 
 
 It 
 
 ^ 
 
 
 ^ 
 
 
 
 v; 
 
 
 
 1 
 
 ^ 
 
 
 
 J 
 
 »i^ 
 
 \ 
 
 f 
 
 ^ 
 
 ^ 
 
 
 •vJ 
 
 5i< 
 
 
 
FREE HAND DRAWING 
 
 45 
 
 I /•*' 
 
 5 '-6 
 
 ■^ 
 
 From ^ Col 26 
 
 Fironx 
 SecanJaftes 
 
 LiM 
 
 Bo'Ck qS fhne./ 
 
 -i^O" FfotnEast 
 
 Wall. 
 
 iTlahbk SUh 
 
 Z'/f"Th.ick 
 
 heveleJ air 
 
 7^2 
 
 // 
 
 FIG. 28. 
 
46 FREE HAND DRAWING 
 
 instruments, switches and fuses on the board and 
 their connections on the panel as well as to the main 
 incoming and outgoing conduit lines. It is custom- 
 ary in all such electrical sketches to distinguish be- 
 tween the heavier and lighter wires or cables by 
 means of correspondingly heavier or lighter lines on 
 the drawing. The panel is usually sketched from the 
 rear showing all the back wiring but also outlining 
 the instruments, switches and all other equipment in 
 their proper places, although they are actually all 
 placed in the front part of the panel. The notes give 
 the location of the switchboard and the character of 
 the material and general construction as indicated in 
 the sketch. 
 
 It might be proper here again to emphasize the 
 necessity for training the powers of observation so 
 there should be very little difference between ''look- 
 ing" and ''seeing." 
 
 This power of observing things is a part of the re- 
 quirements of the modern engineer and it goes hand 
 in hand with his ability to make good free-^hand 
 sketches. In fact, we might say^ that by making a 
 great number of free-hand drawings the engineer gets 
 the benefit of a valuable training as an observer, and, 
 on the other hand, by learning proper methods of 
 observation the engineer becomes an expert in mak- 
 ing accurate !free-hand sketches besides being gen- 
 erally of greater use in the other duties of his profes- 
 sion. 
 
CHAPTER VII. 
 
 Engineering Drawing. 
 
 By Joseph G. Branch. 
 
 In practically all branches of engineering work, 
 drawing is made of extensive use as a medium of 
 expression for the interchange of ideas. So indispens- 
 able is drawing in this connection that it has virtually 
 become the engineers' language, without which they 
 would have great difficulty in making themselves un- 
 derstood. Whenever a piece of construction is to be 
 undertaken, no matter whether it be a huge building 
 or a tiny mechanism smaller than a watch, drawings 
 are practically always used to convey to the builder 
 or mechanician the ideas and wishes of the designer. 
 The day of "cut and try*' in engineering construction 
 has gone, and the more exact modern methods have 
 come to stay. 
 
 This necessity for drawings in connection with all 
 kinds of engineering work has had the effect of 
 standardizing methods of drawing. This has the ef- 
 fect of making the ''language of drawing'' more readily 
 and easily understood by all who use it. Since all 
 engineers use the same methods in their drawing 
 there can be no doubt as to what is meant by a par- 
 ticular drawing, assuming of course that it has been 
 properly and correctly done. 
 
 In general there are two methods which are recog- 
 nized in connection with drawing for mechanical 
 purposes. These are: 1. Perspective Drawing, and 
 8. Mechanical, or Projection Drawing. 
 
 In perspective drawing an oibject is drawn as it ap- 
 pears to the eye, and not necessarily as it really is. 
 The fact that bodies do not appear to the eye as they 
 
48 FREE HAND DRAWING 
 
 really are is one of universal experience. The rails 
 on a track appear to come closer together as they 
 recede from the observer, but wc know that they are 
 always parallel. Houses seen at a distance appear to 
 be smaller than others nearer at hand, although as a 
 matter of fact just the reverse may be the case. So 
 in perspective drawing this is always kept in mind, 
 and the object drawn as it seems to be. 
 
 The value of this kind of drawing depends upon the 
 fact that it conveys to the mind of the observer an 
 idea of what the object shown really looks like. Pat- 
 ent Office drawings, presented in connection with an 
 application for a patent, are frequently made in per- 
 spective. This conveys to the mind of the examiner 
 a definite picture of the object in question, similar to 
 what would be obtained from a model. 
 
 But when an object is to be constructed it is quite 
 evident that the mechanic who is to do the work wdll 
 need something more than a perspective drawing. 
 He must know what the object in question is really 
 like in order that he may be able to make it correctly. 
 So for this purpose a mechanical or projection draw- 
 ing is used, which shows the object as it actually is. 
 To a person who is inexperienced in the use of such 
 a drawing, it will often look very unlike the object 
 which it represents. But experience with mechanical 
 drawings very soon develops in a person the ability 
 to form a mental picture of what the object is like. 
 In other words he learns to *'read'' the drawing, and 
 so get the information which it contains. 
 
 The Mechanical Draftsman. 
 
 The necessity for drawings which show what an 
 object is really like, so that it may be made correctly 
 by one who has never seen anything like it before, 
 has produced the profession of the mechanical drafts- 
 man. It is the function of the draftsman to make all 
 the drawings necessary for the construction of the 
 
FREE HAND DRAWING 49 
 
 object in question. Suppose for example that some 
 special kind of automatic machine is to be built, noth- 
 ing like it ever having been made before. The drafts- 
 man will usually make what is known as an ''assem- 
 bly drawing" of the machine, which shows the entire 
 mechanism completely assembled. In case such a 
 complete drawing is impracticable or undesirable for 
 any reason, he will make drawings which show the 
 essential parts of the machine, put together or as- 
 sembled as they be in the completed object. 
 
 But the draftsman must do more than this. He 
 must make what are known as '^detail'' or "working" 
 drawings, for the use of the mechanics who are to 
 make the various parts of the machine. Such work 
 is usually spoken of in the drafting room as "detail- 
 ing," and consists in making a separate drawing of 
 each individual piece or part which goes into the 
 completed machine. Of course if there are two or 
 more parts exactly alike, only one drawing is re- 
 quired, and then the draftsman simply puts a note on 
 his drawing thus: "Make Two,'' or "Make Four," 
 or whatever the desired number may be. 
 
 Usually the draftsman who makes the detail draw- 
 ings is not the one who made the assembly drawings, 
 although in some cases both drawings may be made 
 by the same man. In case a different man makes the 
 details, he must work from the assembly drawings, 
 and hence the latter must be complete and correct if 
 the details are to be correct. 
 
 When the drawings go into the shop where the ma- 
 chine is to be built, the pattern-maker, the machinist, 
 and other mechanics wilJ work from the detail draw- 
 ings, because they show exactly what the various 
 parts are like. An assembly drawing may or may 
 not accompany the detail drawing into the shop. If 
 it does, the mechanic can see where the piece that he 
 is making is to go in the finished machine. But if 
 
60 FREE HAND DRAWING 
 
 there is no assembly drawing he makes the pieces as 
 they are shown in the details, and his responsibility 
 ends there. If the pieces fail to fit properly when the 
 machine is finished, the error is in the drafting room, 
 not in the shop. 
 
 After all the parts are made they go to the as- 
 sembling shop, where the machine is put together. 
 Here the assembly drawing is of importance because 
 it shows how the various parts go together. The 
 machinist who assembles the machine will therefore 
 be supplied with the assembly drawing, and with all 
 the parts at hand, properly made, he turns out the 
 finished machine. 
 
 The Designer. 
 
 If the machine which we have been considering is 
 something which has never been made before, it is 
 quite proper to ask where the draftsman received his 
 information, which enabled him to make the original 
 designs. He must have had something to work from, 
 because the mechanism to be built must have had an 
 origin somewhere. The answer is that the machine 
 originated with the designer. Having in mind a cer- 
 tain kind of work which he wished the proposed ma- 
 chine to do, he set out to devise a mechanism which 
 would do it. It IS of course unlikely that the first 
 idea which occurs to him will prove to be the desired 
 solution, so he tries one after another until the best 
 one is finally discovered and decided upon. 
 
 In some engineering offices the designer and the 
 draftsman are one and the same person, but in the 
 larger concerns the tendency is to separate the work, 
 having the designing done by one man, and the draft- 
 ing by another. If a man is a designer only, the tools 
 with which he works are simply a pencil, an eraser, 
 and a pad of paper. When he sits down to design 
 his machine, and a particular mechanism occurs to 
 
FREE HAND DRAWING 51 
 
 him as a possible solution of ihis problem, he sketches 
 it out free-hand, so that he may have an opportunity 
 to consider it more carefully. If it looks good, he 
 proceeds to develop the idea, sketching it in as the 
 machine groves in his mind. Certain changes may 
 seem desirable at times, and he simply erases part of 
 what he has drawn and sketches it again according to 
 the new idea. Finally the complete design is decided 
 upon, and sketched on his drawing pad, although of 
 course it is all very rough and unfinished, because 
 done free-hand, that is, without the use of instru- 
 ments. 
 
 Then the designer calls in the draftsman, shows him 
 the sketches and explains the idea to him. The 
 draftsman then makes the finished mechanical draw- 
 ings from the designers sketches. Of course the 
 draftsman must also be somewhat of a designer him- 
 self, because the designer's sketches will probably 
 cover only the main features of the machine, leaving 
 many of the details to be worked out by the drafts- 
 man. So it often happens that the draftsman will 
 make free-hand sketches of a number of different 
 parts of the proposed machine, before he decides defi- 
 nitely on the proper shape and size. After the gen- 
 eral design and many of the details have been fixed 
 in his mind, he will then take up his draftsmans' in- 
 struments and proceed to make the mecanical draw- 
 ings. 
 
 It should be evident from the foregoing that no 
 man can hope to become a successful draftsman or 
 designer if he has no knowledge of free-hand draw- 
 ing. Such drawing forms the basis for most me- 
 chanical drawings, because the free-hand drawing is 
 what the draftsman must work from when making his 
 finished drawing. Every new machine, almost with- 
 out exception^ has its origin in a free-hand drawing. 
 
52 FREE HAND DRAWING 
 
 and hence the latter is the beginning of all engineer- 
 ing drawing. 
 
 After free-hand drawing has been mastered, it will 
 be found that mechanical drawing consists in making 
 the same kind of a drawing, but making it more neat- 
 ly and accurately by means of instruments. Hence 
 a study of free-hand drawing is very essential for 
 anyone who wishes to become a mechanical drafts- 
 man. It is, in fact, a long step in the right direction, 
 and will make the understanding of purely mechanical 
 drawing very much easier. 
 
Examination Questions 
 
54 EXAMINATION QUESTIONS 
 
 FREE HAND DRAWING. 
 
 Directions. 
 No scale or ruler must be used in any free-hand 
 drawings. Only a soft pencil and eraser. 
 
 LESSON ONE. 
 
 Examination Questions. 
 
 1. What are the two principal kinds of sketches em- 
 
 ployed in engineering work? 
 
 2. What is the first thing to learn in free-hand draw- 
 
 ing? 
 
 3. Must the eye or the hand be first trained? 
 
 4. Are free-hand sketches drawn to a correct scale? 
 
 5. How is the pencil held and the line first drawn? 
 
 6. What is the most important element of free-hand 
 
 drawing? 
 
 7. Explain how you would draw a horizontal line? 
 
 A vertical line? 
 
 8. How would you draw an angle? A rectangle? 
 
 9. How a square? An equilateral triangle? 
 
 Exercises. 
 
 1. Draw one hundred straight lines. One hundred 
 
 vertical lines. 
 
 2. Draw a horizontal line one and one-half inches long. 
 
 A vertical line the same length. 
 
 3. Draw five right angles. Five 45 degree angles. 
 
 Five 15 degree angles. Five 10 degree angles. 
 
 4. Draw a triangle. An equilateral triangle. 
 
 5. Draw a rectangle three inches long and two inches 
 
 wide, 
 
 6. Draw a square two by two inches. 
 
 7. Draw a triangle with a base of one and three-quar- 
 
 ter inches. 
 
EXAMINATION QUESTIONS 55 
 
 LESSON TWO. 
 
 Examination Questions. 
 
 1. Which lines are easier to draw free-hand: straight 
 
 or curved? 
 
 2. Give several ways of drawing a circle without the 
 
 use of a compass. 
 
 3. Name the two principal axes of the ellipse. 
 
 4. Give the method for finding the two foci of the 
 
 ellipse. 
 
 5. Which is the easiest way to draw an ellipse free- 
 
 hand ? 
 
 6. How is a cylinder represented by a free-hand 
 
 sketch ? 
 
 7. What is the method used in shading an object 
 
 drawn free-hand? 
 
 8. How would you draw a square pyramid? A hex- 
 
 agonal pyramid? 
 
 9. How would you draw a rectangular prism ? 
 
 Exercises. 
 
 1. Draw a circle by the aid of a silver dollar. 
 
 2. Draw a circle by turning the paper around the in- 
 
 dex finger. 
 
 3. Draw a circle 3 inches in diameter free-hand ; 4 
 
 inches; 5 inches. 
 
 4. Draw several concentric circles (inside one another, 
 
 from the same center). 
 
 5. Draw 3 circles of unequal size tangent to one an^ 
 
 other (touching one another). 
 
 6. Draw an ellipse having a major axis of 3 inches 
 
 and a minor axis of lyi inches; 4 inches by 1>4 
 inches. 
 
 7. Draw a cylinder lying on its side with one of its 
 
 ends exposed to view at an angle. 
 
 8. Draw several (at least three) combinations of cyl- 
 
 inders, pyramids and prisms and shade them 
 properly. 
 
56 EXAMINATION QUESTIONS 
 
 LESSON THREE. 
 
 Examination Questions. 
 
 1. Do objects appear to the eye exactly as they really 
 
 are in nature ? 
 
 2. In drawing a group of objects, which one should be 
 
 taken up first. 
 
 3. What determines the distribution of shading on 
 
 a free-hand sketch of any object? 
 
 4. What is the difiference between shading and 
 
 shadows ? 
 
 5. How does the angle of an object determine the im- 
 
 pression of its length to the eye ? 
 
 6. What is the appearance of a circle placed in a plane 
 
 parallel to the observer? At an angle to the ob- 
 server? At right angles? 
 
 7. How can an object be represented without sharp 
 
 outlines? 
 
 8. What kind of lines are used in representing an ob- 
 
 ject by shading it? 
 
 Exercises. 
 
 1. Draw a combination of a hexagonal prism and a 
 
 cone in three different positions. 
 
 2. Draw a cube at an angle and use no sharp outlines, 
 
 but make up the figure by proper shade lines. 
 
 3. Draw a combination of a cylinder, cone and sphere. 
 
 4. Draw a cone tilted towards the observer at three 
 
 different angles. 
 
 5. Show three sections of a cone. 
 
 6. Show three sections of a square pyramid. 
 
EXAMINATION QUESTIONS 57 
 
 LESSON FOUR. 
 
 Examination Questions. 
 
 1. What is meant by perspective drawing? 
 
 2. How many vanishing points are to be considered 
 
 in drawing an object in perspective? 
 
 3. How are equal distances between similar points af- 
 
 fected by the direction of the vanishing lines ? 
 
 4. How would you draw objects with curved parts 
 
 in perspective? 
 
 5. How are vertical distances represented in per- 
 
 spective drawing? 
 
 6. How would you draw an outline of a street in per- 
 
 spective ? 
 
 Exercises. 
 
 1. Draw an outline of a train in perspective. 
 
 2. Make a mechanical layout or plan of some manu- 
 
 facturing plant. 
 
 3. Show the same plant in perspective, in sharp out- 
 
 line. 
 
 4. Shade the sketch made in exercise 3. 
 
 5. Copy a sketch in perspective from a catalog. 
 
 6. Make the same sketch from memory. 
 
 LESSON FIVE. 
 
 Examination Questions. 
 
 1. What branch of drawing is most frequently used 
 
 for preparing technical illustrations? 
 
 2. What is the difference between an illustration and 
 
 a working drawing? 
 
 3. How can an illustration be prepared accurately 
 
 without looking at the actual object or a model? 
 
 4. What are the principal lines of direction in an iso- 
 
 metric drawing? 
 
 5. What use is made of shading in technical illus- 
 
 trations ? 
 
 6. What is meant by guide-lines as distinguished from 
 
 prominent lines and shade lines? 
 
58 EXAMINATION QUESTIONS 
 
 7. What type of drawing is best to be used for show- 
 
 ing the main features and dimensions of a ma- 
 chine? 
 
 8. What additional information must be supplied to 
 
 make a technical sketch of a machine complete ? 
 
 Exercises. 
 
 1. Make a free-hand sketch of your parlor lamp, or 
 
 some gas or electric fixture. 
 
 2. Copy a sketch of some pipe fitting from a catalog. 
 
 3. Draw the sketch of the same pipe fitting from mem- 
 
 ory. 
 
 4. Make a free-hand drawing of a small pump by ob- 
 
 serving it in 3^our own work. 
 
 5. Add enough dimensions to your sketch to supply 
 
 all the information for a prospective buyer. 
 
 6. Make a study of three or more catalog illustrations 
 
 of a technical nature and see if you can copy 
 them from memory. 
 
 LESSON SIX. 
 
 Examination Questions. 
 
 1. Name several occasions when rapid technical 
 
 sketching is required by an engineer. 
 
 2. What material is required for technical sketching? 
 
 3. What kind of drawing is used for technical sketch- 
 
 ing : mechanical, isometric or perspective ? 
 
 4. What method would you use in making a technical 
 
 sketch of a machine or structure in place? 
 
 5. How is technical sketching used by the designing 
 
 engineer and draftsman? 
 
 6. How would you make a sketch of a structural steel 
 
 or concrete structure ? 
 
 7. How would you make a sketch of an electrical 
 
 switchboard or wiring scheme? 
 
 8. What is the difference between "looking'' and "see- 
 
 ing"? 
 
EXAMINATION QUESTIONS 
 
 Exercises. 
 
 1. Make a sketch of some part of pipe in a steam power 
 
 plant where you are working. 
 
 2. Design a piping system for heating a garage and 
 
 make the necessary free-hand sketches. 
 
 3. Copy a mechanical drawing of a building section 
 
 by the free-hand system. 
 
 4. Draw up a detail of a part of a machine from obser- 
 
 vation or memory, and put in all necessary notes 
 and dimensions. 
 
 5. Draw a free-hand sketch showing the wiring of a 
 
 simple switchboard. 
 
 6. Make a sketch showing wiring of an automobile ig- 
 
 nition system. 
 
 LESSON SEVEN. 
 
 Review Questions. 
 
 1. What is the importance of free-hand drawing for 
 
 the practical engineer? 
 
 2. What is the importance of rapid sketching for the 
 
 designer? 
 
 3. How are machines originally designed? 
 
 4. What is the difference between an assembly and a 
 
 detail drawing? 
 
 5. What instruments are essential for mechanical 
 
 drawing? 
 
 6. What materials are required for free-hand sketch- 
 
 ing? 
 
 7. Why is it not practicable to make all preliminary 
 
 studies by means of scaled mechanical drawings ? 
 
 8. What studies are required to enable the student 
 
 to be trained as a designer? 
 
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