684 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



" 1. It moves the entire body. 2. It is extremely sensitive and 

 direct. 3. It has no lateral motion or displacement of the image, 

 while adjusting. 4. It has absolutely no lost motion. 5. It can in 

 no manner deteriorate." The " Professional " Microscope (shown at 



Fig. 127. 



Fig. 113, p. 667) has the fine adjustment in the form above described, 

 while in the " Model " Microscope of the same makers (Fig. 127) a 

 slight variation is made by the bar e being placed below instead of 

 above. 



Nose-piece for Binocular Prisms. — When the broad gauge (1^ in.) 

 screw is used (for low powers of wide angle), it is necessary to 

 provide some means, not merely for the withdrawal of the prisms of 

 the binocular, but for the removal of its fittings so that the end of the 

 tube may be left quite free for the full diameter of the objective. 



This is perhaps best accomplished by the prism and its fittings 

 being in a separate nose-piece, attached to the tube by a well-made 



