122 



PKACTICAL PHOTO-MICKOGKAPHY 



photographic camera. It may, however, be improved with 



little trouble or cost. Guides should be placed on the base- 

 board for the microscope to 

 drop between, so that it 

 could always be replaced in 

 its proper position, and the 

 same might be done with 

 the lamp and the bull's-eye 

 condenser ; beyond this, little 

 more can be done with so 

 simple an apparatus. The 

 camera has in this case to 

 be kept very short, so that 

 an observer can reach the 

 fine- or coarse-adjustment 

 of the microscope while 

 observing the image on 

 the ground-glass focussing- 

 screen. The possibilities, 

 therefore, of the apparatus 

 are limited, and the work 

 which it is capable of doing 

 would be confined to that 

 with low-power lenses. 



The next step towards 

 greater elaboration should 

 consist of an elongation of 

 the baseboard, rendering it 

 possible to use a camera with 

 greater bellows extension. 

 When this is done it be- 

 comes necessary to have an 

 arrangement for controlling 

 the fine-adjustment of the 

 microscope while the observer 

 is watching the image on 

 the focussing-screen. There 

 are many ways of doing'this, 



and a simple one is that shown in the illustration (Fig. 43). 



A long metal rod is supported on the wooden base and has 



