A DRAWING MODEL. 



139 



utilized to facilitate the study of drawing. A piece of glass is fixed vertically 

 on a black board (fig. 146). A model to copy from is placed on one side of 

 the piece of glass, and is arranged so that the visual ray passes obliquely 

 through the glass, and we perceive the reflection of the design very clearly 

 on the other side. It is then very easily reproduced with a pencil on a sheet 

 of white paper by tracing the outlines. 



Fig. 146. Drawing by 



reflection. 



