ELEMENTARY PHOTO-MICROGRAPHY. 



It will be noticed that in fig. 2 a short tube A 

 is shown, though such is not necessary for ordinary 

 low power work ; but it is a decided advantage to 

 be able to use accessories, such as iris diaphragm, 

 polariscope, spot lens, and substage condenser, all 



FIG. a. 



FIG. 3. 



f",* *x Ny =f 



X'' 



Fio. 6. 

 DETAILS OF SIMPLE MICROSCOPIC OUTFIT. 



of which may be slipped into this tube, thereby 

 extending the field of operations considerably. 

 Such a tuoe is known as an adapter, and may be 

 purchased of most microscope makers for a nomi- 

 nal sum ; the additional fittings for it, of course, 

 may be added when desired. 



