CH. X] 



PROJECTION APPARATUS FOR DRAWING 



327 



The size of the projection table is the same as given above ( 424) . 

 A convenient size for the drawing shelf is 50 cm. (20 in.) long, and 

 25 cm. (10 in.) wide. 



In fig. 183 the legs of the table are square and straight and the 

 shelf slides up and down on the legs, being clamped in any desired 

 position by the thumb nuts. 



FIG. 184. DR. RILEY'S ATTACHMENT TO AN ORDINARY MAGIC LANTERN 



FOR DRAWING. 



(Science, Vol. XXIX, IQOQ, p. 37-38). 



AB Mirror support. 

 CD Mirror and mirror frame. 



F Clamp for fastening the mirror support in position in front of the magic 

 lantern objective. 



E Drawing paper under the mirror. 



In figure 182 is shown a neat and efficient arrangement designed 

 by Dr. B. F. Kingsbury, in which the shelf is hinged so that it can 

 be lowered out of the way when using the drawing table with 

 attached 45 degree mirror. The guides for sliding the shelf up or 

 down and clamping it in any desired position, arc of metal and can 

 be attached to any table whether the legs are square, tapering or 

 of any other form. 



