ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
215 
in a vertical position below the stage. It will be observed that on 
account of both movements being performed by rack-and-pinion, an equal 
speed is obtained for each. The slide-holder is of the non-concentric 
rotary type. There is no substage proper, but a sliding plate carrying 
a rotary wheel of diaphragms is fitted instead of one. 
^ t The foot is particularly interesting; it is circular with the vertical 
Fig. 47. 
pillar attached excentrically to it ; the base rotates so that great stability 
can be secured when the Microscope is used either in a vertical or inclined 
position.* 
This Microscope is signed And w . Ross, and has his address, 
* For the earliest form of this often reinvented adaptation see a Microscope by 
J. Cuff, circa 1765, figured Journ. K.M.S., 1898, p. 675, fig. 117. 
