ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



1039 



Fig 203. 



motion for the fine-adjustment, and a revolving diaphragm fixed to a 

 separate arm so that it can be swung out of the optic axis. The con- 

 cave mirror is attached to a bar, the axis of which lies in the plane 

 of the stage, so that illumination may be directed on the object from 

 any point below or above the stage. The base and arm are japanned, 

 the latter being fastened at any desired angle by means of milled 

 heads in the pillars. 



Crouch's Grand Model, 

 Premier, and Student's Mi- 

 croscopes. — Messrs. Henry 

 Crouch (Limited) have made 

 the following improvements 

 in their Grand Model (fig. 202) 

 and Premier Microscopes (fig. 

 203), as also in the Student's. 



The coarse-adjustment has 

 spiral rack-and-pinion move- 

 ments, insuring perfect 



