248 



PHOTOMICROGRAPHY 



To take a photograph the light and condenser are 

 adjusted as usual, and an image of the object sharply 

 focussed on the ground glass of the camera. The lateral 

 eyepiece is then adjusted, by rotating the top lens, until 

 the image it forms on the card is simultaneously in focus 

 with that projected on the ground glass. The dark slide 



Fig. 71 



APPARATUS FOR LIVING ORGANISMS 



is then introduced, the automatic shutter situated above 

 the eyepiece set to the time required, and attention 

 directed to the image on the card until the proper instant 

 for exposure presents itself. Alterations in the focus to 

 sharpen the image on the card will have the same effect 

 on the image in the camera. The loss of light due to the 



