98 8UMMARY OF CURRENT RESEARCHES RELATING TO 
directions. The latter is simply placed upon the stage and is held firm 
by the pressure of the spring on the right against the stop on the left. 
The forward movement is effected by the rack and pinion, and the 
lateral by the transversal screw. As seen in the figure the apparatus is 
attached to the ordinary stage by a screw pressing against the column 
of the slow motion. 
(3) Illuminating- and other Apparatus. 
Nachet’s Camera. — The new camera, shown in fig. 7, is mounted on 
two columns of nickelled copper on which it can be raised to different 
Fig. 7. 
heights above the Microscope. The columns are hinged so that the 
camera can be inclined at any angle. 
