PHOTOGRAPHIC EQUIPMENT 



501 



director of the laboratory describes. This will involve par- 

 ticularly a lens which is capable of being used to photograph 

 objects at very close range, e.g., at a distance of 12, 10, or 

 even 6 inches. This is required in copying such objects as 



_ ' 



Object board moveable 

 up and down,s!dewise, 

 forward, backward,or 

 thru 3 small arc, about 



Fig. 386. Method of arranging the camera and arc light for copying. The pul- 

 ley supporting the arc light should be attached to the ceiling. (Second hand arc lamps 

 can often be bought of the Gregory Electric Company, Chicago, 111.) 



printed pages (which is often of great service when one 

 wishes to keep an exact record of an article in a borrowed 

 journal, etc.) and for making lantern slides of pictures, 

 tables, charts, tracings, etc., from books or kymographic 



