812 



SI'MMAKY OF CURRENT RESEARCHES RELATING TO 



The aperture in the stage is 1 •'.) in. in diameter, and a reducing ring is 

 supplied. Half an inch below the bottom of this stage is a " turn out 

 ring with an aperture the same size as that in the stage, so that the disks 

 which fit one will fit the other. The construction of the arm at the top 

 of. and at right angles to, the limb is peculiar, and unlike that in any 



Fig. 94. 



other Microscope. It is very short, and it is capable of being rotated 

 and clamped in any position by a screw. This arm has a broad V-groove, 

 to which a second arm, carrying the optical part, can be attached 

 ami clamped by another screw. This is a novel and excellent mode of 

 attachment : half a turn of the screw firmly fixes it in position, and half 

 a turn releases the body from the limb. It would be difficult to devise 



