26 



THE AMERICAN MONTHLY 

 MICROSCOPICAL A ViW llATUS. 



[Jan . 



Attachable Mechanical Stage for Microscopes With 

 Plain Stages. 'J'his Staj^e consists of a suitable base-plate 

 ])ro\i(k'(l with thumb-screws littinj^- into the clip-holes and 

 fastiMU'd from In-low. Upon the i)ase-plate are two sliding 



pieces inountctl at fiu'lit an<i-les to one anotlu'i" and moveil 

 in riy^ht lines by two milled heads, 'i'lie i^erpendicular 

 movements are controlled by rack and jiinion, anil extend 

 an inch and a (juai-ter. The horizontal movements extend 

 full two inches and are controlled by a micrometer screw. 

 These sliding- pieces pass along' suitable scales whereby 



