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. 



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

 in a Horizontal Position [Zeiss' 1 Special Catalog.) 



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

 parent objects M 2 [mirror 2) is removed, when the light striking Mi is reflected to 

 M 4 and thence up through the object to M 1 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 M 1 . M 1 serves to reflect 

 the rays from the objective to the screen. 



V. Ventilator. 3P and M 4 are mirrors for use in reflecting the light through 

 horizontal transparent objects. 



