354 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



It may be pointed out, says E. M. Nelson, that an instrument "of 

 this kind, fitted with achromatic loups, would be very serviceable to* a 

 microscopist for field work. 



It will be remembered that three of Dr. Gairdner's Microscopes, 

 made by Bryson of Edinburgh, were exhibited, figured, and described 

 in the journal for 1899, p. 643, fig. 149. 



Fig. 67. 



These had Coddington lenses, each power having a separate Micro- 

 scope to itself. Gairdner's Microscope was described in the first edition 

 of Carpenter on the Microscope, 1866, p. 74, fig. 15, and there it is said 

 to be of use in bed-side investigations of urinary deposits. 



In design, Gairdner's Microscope is far inferior to that of Pillischer's, 

 inasmuch as there is no possibility of either moving the slide under the 

 lens, or the lens over the slide, so nothing can be seen except the single 

 point in the axis of the lens. 



Seibert's Large Model Microscope No. 2. — This stand (fig. 68) 

 closely corresponds to Zeiss' Model 1a ; but is sold at a much less 

 price. The fine adjustment, unlike Seibert's largest model, is by a 

 jjrismatic bar, the micrometer screw being placed on the prism collar. 

 When inclined the Microscope can be clamped by a lever. The stage 

 is circular, graduated on rim, rotatory, and provided with centring 

 screws. It is interesting to note that the horse-shoe foot is replaced by 

 a flat tripod. 



Watson's New "Holos Fram" Microscope. — This instrument 

 (fig. 69) is Messrs. Watson and Sons' " Fram " Microscope, fitted with 

 a rigid mechanical stage, and centring rackwork substage. 



New Two-speed Fine Adjustment. — Messrs. W. Watson and Sons' 

 new two-speed fine adjustment (fig. 70) is an ordinary single micrometer 

 screw, having the usual larged milled head, and a projecting spindle- 

 head, also milled, and of convenient length. When the latter is made 



