344 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



MICROSCOPY. 



A. Instruments. Accessories, etc.* 



(1) Stands. 



James Swift's Fine-adjustment.t — E. M. Nelson contributes an 

 interesting historical memorandum on this fine-adjustment, which he 

 considers to be the best ever fitted to a body with a long slide. It was 

 made by the late James Swift in 1881 for his " Wale's Students' " 

 Microscope, and consisted of a vertical lever which moved the nose- 

 piece only. From figs. 56 and 57, which show the Microscope set up 



Fig. 56. 



for critical work with substage condenser, it will be seen that the instru- 

 ment had a bent-claw foot, a large-cut horseshoe stage, a sliding bar, 

 and a substage with rectangular movements formed by a Swift's centring 

 nosepiece with rack-work focusing attached. This substage, fitted with 

 Powell's celebrated side-angled achromatic condenser, had a swing-out 

 rotating carrier below, and Nelson considers that this condenser, except- 

 ing Powell's apochromatic, is still the best made either here or on the 

 Continent. Swift shortly after brought out his " Challenge " Micro- 

 scope, in which the same form of lever moves the whole body and coarse 

 adjustment, after the Zentmayer model. This may, perhaps, cost some 



* This subdivision contains (1) Stands ; (2) Eye-pieces and Objectives ; (3) 

 Illuminating and other Apparatus ; (4) Photomicrography ; (5) Microscopical 

 Optics and Manipulation ; (6) Miscellaneous. 



t English Mechanic, xciv. (1912) p. 603 (3 figs.) ; xcv. (1912) p. 60. 



