THE MICROSCOPE. 37 



to each other and to the axis of the body, given by the milled- 

 heads, e, e f ; it has also a sliding and revolving plane, /, with 

 a ledge, </, for resting object-slips upon, and a sliding-piece, A, 

 with springs for clamping them. An upright rod, i, is fixed 

 on this plane for mounting the forceps, v y or for the spring- 

 holder, y, when a glass trough, u, is used. A profile of the 

 glass trough, with its diagonal plate of glass for conforming an 

 object, is seen at u f . At z, is a three-pronged forceps. 



A large double mirror, &, concave on one side and plane on 

 the other, is supported by the cylindrical bar, Z, and may be 

 moved upon it vertically and sideways. 



A movable diaphragm, m, is fixed under the stage for vary- 

 ing the quantity and direction of the light when transparent 

 objects are viewed. The illuminating lens, n, is used for con- 

 densing light upon opaque objects ; and a silver side-reflector 

 is for the same purpose. The bull's-eye lens, for increasing the 

 illumination, is seen at r. 



An achromatic condenser, x, slides into the place of the 

 diaphragm, to give the utmost refinement to the illumination of 

 transparent objects. 



The live-box, s, is for observing living objects between two 

 glass plates ; and a second live-box, s', with screw collar, for 

 objects in water. The screw is for regulating the depth of 

 water, and the degree of pressure employed. 



A plate of glass, t, with a ledge, has a separate piece of thin 

 glass to lie upon it, for viewing animalcules, &c., in water. 



The camera lucida, w, has its prism fixed on a short tube 

 with a slight side motion for adjustment, and fits on each eye- 

 piece when its cap is removed. 



The three Lieberkuhns, o, o', o", adapted to the object- 

 glasses 2, 3, and 4, are applied by sliding them in front of 

 each respectively. When one of these is used, the diaphragm 

 is to be removed, and the dovetailed piece, p, may be slid in its 



4 



