THE COMPOUND MICROSCOPE. 



79 



of the instrument is efFected by rack and pinion, by which the 

 triangular bar, H, and with it the arm, I, carrying the com- 



Fig. 44. 



pound body, K L, are moved up or down, the rack being 

 situated at the back of the triangular bar and the pinion con- 

 nected with the large miUed head, E. The fine adjustment 

 is made by turning the screw, S ; this acts on the end of a lever 

 contained in the hollow arm, I, by which the short tube, T, to 



