MICROSCOPIC CHROXOPHOTOGRAPHY 295 



is the first to be arranged, and this is carried out by 

 means of the knob B, which controls a rack, and finally 

 by the long rod mv, which turns a micrometer screw. 



The microscopic object-glass is then brought to 

 bear upon the preparation. 



The rays from the object then cross a square metallic 



Fig. 200.— Special apparatus adapted to cbronophotography for studying the move- 

 ments of microscopic specimens. 



box behind the lens, and finally traversing the wooden 

 box, and the bellows attached, reach the ground glass 

 of the image chamber.* 



From the side of the metallic box the tube of a 

 microscope runs obliquely, and is provided with an 

 ordinary eye-piece. By an arrangement invented by 

 M. Xachet, the image can be projected either on to 



* For the description of this chamber refer back to p. 116, Fig. 80. 



