In the Continental form of microscope where there 

 is no provision for swinging or placing the mirror above 

 the stage, one is dependent upon the direct source of 

 light when, in the case of lamp light, the lamp should 

 be raised to a higher position. When the light so 

 obtained is not sufficient for proper examination, 

 recourse must be had to a separate apparatus, the 

 bull's-eye condenser. This is a plane convex lens of 

 strong curvature fixed to a stand giving adjustments in 

 different directions. It is interposed between the light 

 and the object, with its plane side toward the object 

 in such a manner that the lens will concentrate the 

 light upon its upper surface. 



'53 



