266 



PROJECTION MICROSCOPE 



[CH. IX 



Each preparation should be wiped off before it is put in position 

 on the stage. Any particles of dust are painfully evident in the pro- 

 jected image. 



V 



Fig. 214. Zeiss Epidiascope for Opaque Objects, and for Transparent Objects 

 in a Horizontal Position (Zeiss' Special Catalog.) 



As shown in this jigure the apparatus is set up for opaque objects. For trans- 

 parent objects M 2 (mirror 2) is removed, when the light striking Mj is reflected to 

 III' and thence up through the object to M' and to the screen. 



Commencing at the right : R. Parabolic reflector, which projects the light from 

 the crater through ( W ) the water bath, to M 2 the mirror which is at the proper an- 

 gle for reflecting the light down upon the opaque object. From the opaque object the 

 light is irregularly reflected up through the objective to 31'. M' serves to reflect 

 the rays from the objective to the screen. 



V. Ventilator. M ; and HI' arc mirrors for use in reflecting the light through 

 horizontal transparent objects. 



