THE CAMERA, ETC. 41 



THE CAMERA AND OTHER APPARATUS. 



As the camera plays a very important part in 

 photo- micrography, we recommend the reader, un- 

 less he is a first rate mechanic, to purchase one; 

 great care being required in its manufacture. It 

 should be quarter plate size, with bellows body, 

 the interior lined with black velvet. The focussing 

 screen which should consist of the finest patent plate 

 (oiled), must be carefully adjusted to occupy exactly 

 the same position as the sensitized plate. 



It will be found convenient when working with 

 dry plates, to have one or two double dark slides. 

 Several plates can then be exposed consecutively, and 

 if developed together a great waste of time and solu- 

 tion is avoided. 



The front, to which the lens is attached in ordi- 

 nary photography, should slide in groves fixed to the 

 body of the camera, we can then substitute for it 

 a conical bellows, similar to that in fig. 24, also 

 lined with black velvet. 



To the end of the conical bellows a tube an inch 

 long is attached, this fits into the short tube of the 

 microscope smoothly and accurately, its interior 

 must be blackened, or better, covered with velvet, 

 to prevent reflection from the sides. 



The distance of the focussing screen from the 

 front of the camera should be regulated by a rack 

 and pinion or screw motion, and when the desired 



