THE MICROSCOPE, ETC. 



27 



aid of the finger alone without the use of milled 

 heads or other mechanical arrangements. 



This is best accomplished by ivory points moving 

 on a blackened glass surface, a method extensively 

 employed by some of our leading opticians and likely 

 to supersede all others where real work is the object 

 iu view, not a desire to catch the eye of the public. 



FIG. 15. 



The accompanying figure represents a slightly 

 modified form of Smith and Beck's popular monocu- 

 lar microscope. The method adopted for the inclin- 

 ation of the body is susceptible of improvement, but 

 up to the present we have seen few stands to which 

 the same observation is inapplicable. 



The tube A carrying the eye-piece, screws into 

 B, which is permanently attached to the arm X 

 carrying the objectives. The coarse and fine adjust- 

 ments are conveniently placed, especially for photo- 

 graphy, and their performance sufficiently perfect for 

 most purposes. 



The stage has been considerably modified, as the 



