THE COMPOTIND MICROSCOPE. 89 



direction of the hand. The object-plate is provided with a 

 spring cKp, N, capable of being slid up and down, and of being 

 turned upon the upper plate of the stage, and is always moved 

 with it. To the under side of the stage, the diaphragm, E, is 

 seen attached. Mr. White's lever stage, of which the above 

 described is a modification, is represented by fig. 46, as fixed 

 for use to the lower end of the arm supporting the compound 



body. The mirror, S, is of 

 large size, and is mounted on 

 a tube, W; it has plane and 

 concave reflecting surfaces; 

 the frame is supported by a 

 semicircular piece of brass, T, 

 with two pins for it to turn 

 on, at U is a joint on which it 

 can be moved horizontally, and 

 at V another joint for turning 

 it away from the axis of the 

 instrument, so that very ob- 

 lique light may be sent through 

 the hole in the stage, and by 

 means of the short tube it may 

 be sHd up and down on the 

 support, W. In the arm, C C, 

 may be^seen two square holes, 

 d d, into these the supports of the side reflector and of the 

 small condensing lens are made to fit, and are kept firmly 

 fixed by the screws, D D. 



To this instrument, if preferred, another stage may be 

 fitted, as exhibited in Plate 3, fig. 2, where A represents part 

 of the large arm for supporting the compoimd body, B one of 

 the pillars, C the joint, and D the tube for the mirror. The 

 stage-plate, E, carrying the object-plate, F, is moved from side 

 to side by the miUed head, G, connected with a screw, whose 

 axis passes through to the opposite side of the stage, where 

 there is another nulled head, and up and down by a rack and 

 pinion connected with the milled head, H. 



Fig. 46. 



