XXVlll 



REMARKS TO THE STUDENT 



ings, limit the source of light to the upper left-hand corner at an angle 

 of 45° and draw the shadows accordingly. Such mechanical drawings 

 may be very elaborate. We shall not attempt too much but merely 

 show how the suggestion of shadows in suitable places will add to the 

 line figure. Thus in Fig. 5, as compared with Fig. 2, the addition of 

 the shadow that would be thrown by the upper objects upon the lower 

 ones makes the appearance much more realistic. In Fig. 4 the ten- 

 tacles below the mouth are left white and thus contrast with the 

 shadowed background of the body in this region. The mouth is dark- 

 ened for the same reason that one would darken the opening to a cave. 

 The way in which a touch of such shading adds to the line drawing is 

 shown in Fig. 8 by the stippling of the limbs where they join the body. 

 Other examples will be found in the drawings throughout the present 



B 



Fig. 6. — Principles of shading applied in representation of a sphere, a cylinder, 

 and in the organs of an animal's body. 



volume. Having completed a good line drawing, you can try adding 

 a bit of shading here and there until you learn how to handle the same, 

 making it a rule to add less rather than more, since there is always 

 danger of smudging. The three principles of shading that are impor- 

 tant for our purposes are the shadows on a sphere, those on a cylinder, 

 and those cast upon an object by one above it, as shown in Fig. 6, 

 and in Fig. 5 as previously explained. Since application of these prin- 

 ciples and those of line drawing appears in the figures throughout this 

 book, it may be helpful to examine these drawings. Even though you 

 are unfamiliar with the objects represented, you can appreciate the 

 means employed to suggest the third dimension by lines and shadows. 

 It is easier to add such shadows to a line drawing made with pencil 

 than to one made with ink, but the principles in distribution of light 

 and shade are the same in the two cases. Delicate effects may be 

 obtained in pencil drawings by rolling a piece of filter paper into a 

 close cylinder about 5 mm. in diameter and twisting it into two pieces. 



