XXIV 



REMARKS TO THE STUDENT 



or a solid object may be indicated by addition of lines to the right, 

 as in I. 



e H I 



Fig. 1. — Use of lines in mechanical drawings. 



If we deal with one object lying above another, as shown in Fig. 2, 

 the principle is to have the lower object hidden by the upper one or 



D £ 



Fig. 2. — Use of lines in representation of various objects. 



shown by lines that are broken. Thus, the two pairs of parallel lines 

 in Fig. 2 A suggest nothing of depth ; they are like the crossing of two 

 street-car tracks. The rectangles in B are no better, but in C it is 



