120 



SUMMARY OF CURREKT RESEARCHES RELATING TO 



The modifications consist in (1) an increase in the length of the 

 radial inclining limb, so that the body-tube is carried more forward, 

 thus providing space for the complete rotation of the ordinary form of 

 mechanical stage ; (2) the application of the fine adjustment to a slide 



Fig. 8. 



in front of the coarse-adjustment slide, so that the whole body-tube 

 is acted upon, and not merely the nose-piece, as in their original form 

 shown in Vol. I. (1881) p. 297, fig, 43 ; two adjusting screws enabling 

 the movement to be regulated with great delicacy ; (3) the application 

 of the double " stepped " diagonal rackwork for the coarse adjustment 



