CHAPTER II 



THE MICROSCOPE AND OPTICAL 

 APPARATUS 



The primary essentials in photo -microg- 

 raphy are a microscope and a camera, or 

 their equivalents. These may be combined in 

 one instrument, as was actually done in a com- 

 mercial way by the Atwood Camera-Micro- 

 scope a number of years ago, but long since 

 discarded u for good and sufficient reasons." 

 There must be a lens to magnify the object 

 and project its enlarged image either direct 

 or through an eye-piece upon the sensitized 

 plate, which in turn must be held in position 

 to receive it by a camera or some contrivance 

 answering the same purpose. Of these, the 

 microscope is the more important, since with 

 no camera, however complete in design and 

 workmanship, can one make even a passable 

 photo-micrograph, if the optical portions of 

 his apparatus, the lenses or objectives, are 

 not properly corrected for the work. Almost 

 every one may, at a pinch, construct some- 

 thing that will answer for a camera, but very 



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