ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
537 
Flint’s Class Microscopes.* — Dr. James M. Flint has devised these 
instruments for class or public exhibition of slides not requiring very 
high magnifying powers. Dr. Flint says that his first appliance for 
this purpose was an accessory to the ordinary Microscope stand, and 
consisted of a circular plate of pasteboard (fig. 131) made to revolve 
upon a pivot attached to the stage, the plate carrying a series of objects 
mounted upon small discs or small squares of glass ; but this arrangement 
Fig. 1 31. 
was only suitable for class use under the immediate supervision of the 
instructor. 
Fig. 132 shows the form of the instrument adapted for public use. 
The principle of the rotatory stage has been developed by enlarging the 
circular plate, enclosing it securely in a box with a glass top upon 
which the Microscope is fastened, giving a rotatory motion to the stage 
by means of a friction roller operated by a rack-and-pinion controlled 
by another milled head in close proximity to the former. By a com- 
* Ann. Keport of Smithsonian Institute, 1896, pp. 96 and 7 (4 pis.); Scientific 
American, May 6, 1899, p. 282 (3 figs.). 
