590 



Transactions of the Society. 



Fig. 70 shows the apparatus in the position corresponding to 

 direct observation with the Microscope in an inclined position. 

 The movements of the camera above detailed allow compensation 

 for any change in inclination. 



The camera stands some 15 in. to the right of the Microscope, 

 leaving a space sufficient for the worker to move his hands and 

 manage the Microscope. 



When the object has been found and is well illuminated, all 

 that is necessary is to take off the eye-piece and put on the prism 

 eye-piece (or to put the prism over the eye-piece used for the 

 direct observation) and turn the camera through 90° to the position 

 of fig. 71, and adjust the cap of the prism to the collar on the 



Fig. 71. 



camera front. The image is then projected on the ground-glass 

 screen and any necessary alterations in focusing, etc., carried out. 



When focusing it will be found that the right hand easilv 

 reaches the screw of the Microscope, the maximum length of the 

 camera being • 8 m. 



The shutter controls the exposure. The same illuminating 

 apparatus is employed for direct observation and for photomicro- 

 graphy. Perhaps the best illuminant for the purpose is the Nernst 

 lamp, modified by Greil (three filaments crossed star-like, instead 

 of one only), because the light is very intense, very steady, and 

 gives a uniformly lighted field. It can be placed either to the left 

 of the operator, as it is shown in these figures, or facing the 

 Microscope. 



