46 THE A B C OF PHOTO - MICROGRAPHY 



of any size the world over. A neat little fix- 

 ture for its use in photo-micrography is sup- 

 plied by the Welsbach Company, and its use 

 is fully recommended to those whose work is 

 principally confined to low and medium pow- 

 ers and the photography of tissues. 



Last to be named but scarcely least in im- 

 portance among radiants is the reliable, uni- 

 versally available coal oil lamp. It can be ob- 

 tained everywhere the world over, and its yel- 

 low rays are capable of making as good nega- 

 tives of most subjects as are those from any 

 other source of light if properly utilized and 

 given sufficient time. The somewhat feeble 

 illumination and inordinate length of exposure 

 required when using high powers are diffi- 

 culties which cannot be fully eliminated, 

 though they may be lessened by careful 

 manipulation, but the finished negatives will 

 compare favorably with those made by any 

 other radiant. On the whole, this familiar 

 light may be commended as being one of the 

 most useful to the photo-micrographer, not- 

 withstanding the rather contemptuous manner 

 in which it is spoken of by the " authorities." 



Having settled upon the radiant, our next 

 procedure is to determine the manner in which 

 it must be employed for the illumination of 



