ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



635 



ment and tightened up the pinching-screw, the fine-adjustment can be 

 applied. 



It will be noticed that this instrument is not a stage-focusing one, 

 the optical parts being focused on the object as in modern Microscopes. 



The principal points of difference between this instrument and its 

 progenitors — the New Universal Simple and the New Universal Double 

 Microscopes — which form improvements of more or less importance, are : 



1. A double mirror carried on a bridle, instead of a single mirror 

 hinged at the back. 



2. The stage, and also the forceps, are carried on fittings that slide 

 sidewise into a dovetailed groove on the pillar, instead of being fitted 

 with shanks that were pushed into a hole therein. 



Fig. 97. 



3. There are eight lenses in the disk instead of six, and three lieber- 

 kuhns instead of one. There is also a special fitting, seen in the figure, 

 for carrying the lieberkuhns. 



4. In the " Universal Double Microscope " there is a prolongation to 

 the pillar above the level of the disk ; on this is fitted a sliding socket 

 carrying at its lower end the rotating disk, and at its upper end there 

 projects a bracket for carrying the body, so that the optical parts can 

 be raised or lowered for focusing. In this instrument the body, as 

 previously described, is inserted in an eye formed in the periphery of 

 the fixed wheel ; by this arrangement one stand serves for both " single " 

 and " double " Microscopes, and the upward extension to the pillar is 

 not required. 



