AN ORDINARY MICROSCOPE ADAPTED TO 

 METALLOGRAPHY. 



By F. Ian G. Rawlins, F.R.M.S. 



The purpose of the following brief note is to draw attention to 

 certain details of a more or less minor nature, which, when incor- 

 porated into an ordinary microscope stand, render it decidedly 

 efficient for metallographical work, where an elaborate outfit is not 

 desired. Although post-war models are now appearing by the leading 

 makers for this branch of microscopy, there is a decided advantage 

 in being able to use an ordinary stand, and the expense involved 

 in the modifications is very moderate. Lastly, the additions are 

 such that they can be easily carried out, even in the present abnormal 

 state of the trade; and they are no detriment to work on trans- 

 parent objects. 



n 



Fig. I. 



Vertical and Horizontal Sections 

 of Plug. 



(1) Siihstage Fitting. 



The point of this is to overcome the trouble inherent in the use 

 of ordiiiary stands for opaque objects with the vertical illuminator, 

 /.r., that on re-focussing, the centering of the illuminator and light- 

 source is disturbed. Assuming that the stand possesses no substage 

 appaiat IS (a])art from the mirror), a focussing substage is fitted, 

 provided with coarse adjustment, rack and pinion. Instead of the 

 usual condenser, a solid brass plug (circular, and of the shape 



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