404 COPYING DRAWINGS. 



on geometrical rules, and which is executed by the 

 use of the ruler and compasses : such as the draw- 

 ing of plans, elevations and sections of buildings, 

 machinery, &c. This species of drawing is of very 

 extensive utility, and is of so easy acquirement 

 that it may be learned by every person in the same 

 manner as writing. 



For this purpose the geometrical problems should 

 first be carefully and neatly drawn, and the hand 

 should be accustomed to the use of the compasses 

 and drawing-pen. Then the architectural mould- 

 ings should be studied, as they occur not only in 

 buildings, but also in cabinet-work, machinery, and 

 almost all kinds of implements. 



In this kind of drawing the outlines of objects 

 are laid down from actual measurement, by scales 

 of equal parts; and the lines are drawn first with 

 black lead pencil, and afterwards with ink, by 

 means of the steel drawing-pen. The shadows also 

 are added in Indian ink, and are drawn by rules 

 that are established with mathematical precision. 



OF THE MECHANICAL MEANS FOR COPYING 

 DRAWINGS. 



There are various methods by which those who 

 are ignorant of the art of drawing may copy very 

 accurately the outlines of pictures, prints, and 

 drawings J and these methods are often useful to' 

 those who can draw, and to engravers, when either 

 great expedition or great accuracy is required; 

 though none of them should ever be used by one 

 who is learning to draw. 



Tracing a gainst the Light. 



Hold the drawing you wish to copy against one 

 of the panes of the window j or have a pane of 



