1881.] 



MICEOSCOPICAL JOUKNAL. 



145 



permit the focussing of a three-inch 

 objective. The fine adjustment is by a 



very dehcate spring movement, con- 

 trolled by a large milled head at the 

 rear of the body, most conveniently 

 placed for the hand. 



The stage-ring or platform, is made 

 of very thin but stiff brass, with a 

 large, central opening, and is provided 



Fig. 29. 



with removable and reversible spring 

 clips, exceedingly delicate, and 

 adapted to any thickness of slide. By 



these a slide may be clamped on either 

 the upper or the lower side of the 

 stage and manipulated with the great- 



