ELEMENTARY PHOTO-MICROGRAPHY. 21 



there and then, or put it in a box for another time. 

 There is much less danger of disturbing the appara- 

 tus by this method than when using an adapter for 

 the dry plate and drawing the dark slide in the 

 usual way. 



It will be understood that objects to 1 be photo- 

 graphed in this way must be transparent, but 

 opaque objects may readily be taken by altering the 

 mode of illumination. When this has to be done, 

 the bellows of the quarter-plate camera should be 

 closed entirely, the wood slide having been with- 

 drawn and mounted on a stand at the same distance 

 from the lens that it would have occupied had the 

 object been transparent. A clear space between the 

 lens and the object will thus be left. A paraffin 

 lamp and bull's eye are now brought round to 

 illuminate the opaque object from the front instead 

 of from the back, as in previous attempts. 



A silver side reflector, usually of the parabolic 

 form, will take the rays of light from the lamp 

 and distribute them over the object, if it is not too 

 large. Unless properly done, one side will be sharp 

 and the other side fuzzy, owing to deficient lighting. 

 Magnesium will be found to give good light and 

 shade with this class of object. 



