ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



007 



Mr. J. Mayall, jun.,* some improvements have been recently introduced. 

 The milled heads for the movements of the two slides are set co-axially, 

 and preserve their position during rotation. The horizontal movement 

 can be effected by either the right or the left hand. The range of the 

 movements has been slightly increased and now extends to 60 by 30 mm. 

 An accurately gauged centring glass, on which are engraved the distances 

 of the cross-strokes from two edges of the object-carrier, is supplied with 

 each stage. Fig. 110 shows the stage as applied to Stand IV a. 



G-reenough's Binocular.f — The Zeiss firm now make the upper part 

 of this instrument with the doublo tube removable ; after the removal of 

 this upper portion the stand can be replaced by a vulcanite fork to which 

 the tube-carrier is screwed (fig. 111). Thus a portable instrument is 

 formed which can be applied to the examination of objects of any kind : 

 it may, for instance, be used as a dermatoscope for skin investigations. 



Docket 



r.!LLEUM£.\D 



f-'wNOi-E 



- <v> lono &6 rcQaired. 



Fig. 112. 



Microscope Adjustment.! — A correspondent, "Treadle," to the 

 English Mechanic, after noticing the tendency of Microscope makers to 

 reduce cost by omitting the fine and by improving the coarse adjust- 

 ment, suggests a revival of the following old device (fig. 112) in use 

 some forty years ago, but now apparently forgotten. It consists of a 

 sleeve fitting loosely on the shank of either of the coarse-adjustment 

 milled heads, with a socket attached into which can be fitted* a handle of 



* This Journal, 1885, p. 122. 



+ Zeiss' Catalogue, 1902, No. 95, fig. 356, p. 73. 



% Eng. Mech., lxxv. (1902) pp. 207-8 (1 fig.). 



2 s 2 



