ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



473 



his sister, Miss Celia Waters at the October Meeting, 1902.* It is 

 mounted on a brass tripod-foot, with circular pillar, having joint for 

 inclination. 



The coarse-adjustment is by rack-and-pinion, attached to the stage, 

 which moves up and down a square bar ; the latter also carries the mirror, 

 which is of a concave form, in gymbal. 



There is no fine-adjustment, but the arm carrying the body is pro- 

 vided with rack-and-pinion, which moves from back to front, and as the 

 whole is mounted on a rotating centre, the body can be brought to almost 

 any part of the stage. 



Explanation op Fig. 69. 



A. Lower plate. 



B. Lever giving motion to upper plate. 



C. Three studs, to keep plates apart. 



D. Circular disk, held up to underside of stage by screws E, and which 



acts as a spring and also holds the plates together. 

 G. Two fixed points upon which the levers turn. - i^^^ 

 H. Studs screwed into upper plate, and by means of which the move- 

 ment is obtained. 



The most interesting part of this old Microscope is the lever- 

 mechanical stage, engraved " Varley and Son." It consists of two 

 parallel plates, the upper one being moved in any direction by aid of 

 a long lever which extends almost down to the foot ; a diagram of the 

 parallel motion is given above, with explanatory note (fig. 69). The 

 upper plate of the stage carries a sliding plate with V-shaped fittings. 



* See this Journal, 1902, pp. 721 and 722. 

 Aug. 21st, 1907 



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