104 ELEMENTARY PHOTO-MICROGRAPHY. 



With all modern high or slow speed plates there 

 will be found instructions for using the particular 

 developer recommended by the makers. 



TIME DEVELOPMENT. 



The Watkins system of developing by time is 

 now often used. This is based on the time between 

 pouring on the developer and the first appearance 

 of any image. A multiplying factor is given for 

 various developers to secure a standard amount 

 of contrast. 



