230 APPLIED SCIENCE 



squarely at the object from the top. This view is often 

 called the plan. The side view is the view obtained by 

 looking squarely at the object from the end. This view is 

 often called the profile view or the end elevation. 



275. Distinction between Working and Perspective 

 Drawings. A perspective drawing is one that portrays 

 an object as it appears to the eye from one point of view. 

 The rails of a car-track, for instance, appear to converge. 

 The parallel lines of any object appear to the eye to converge 

 in like manner, and a perspective drawing will show this 

 feature. Any picture or photograph furnishes an example 

 of the perspective drawing. 



The working drawing, on the other hand, is designed not 

 to present a picture, as is the perspective drawing, but to 

 indicate all the various parts of the object together with their 

 dimensions. In other words, a working drawing is really 

 three distinct drawings of the same object, each of which 

 is drawn from a different point of view. A working drawing 

 of a cube, for instance, would comprise three drawings exactly 

 alike, because a cube presents the same appearance whether 

 viewed from the front, top, or side. A working drawing of a 

 book, on the other hand, would present drawings of three 

 rectangles, each of which would have different dimensions. 



This distinction between a perspective and a working draw- 

 ing is an important one, but once made clear, is very simple. 

 A perspective drawing is the result of what the eye sees, 

 while a working drawing is the result of what the ruler and 

 compass tell. 



276. Tracing Cloth. Tracing cloth consists of muslin 

 cloth heavily sized and pressed to make it translucent and 



