OUR PHYSICAL WORLD 



in small tubes, five to a box. Also purchase one half-pound 

 box of acid fixer. Be sure that the tray, fixing bath, and all 

 apparatus to be used are washed clean. Dissolve the fixer in 

 32 ounces of water, and fill the fixing bath. Now dissolve the 

 contents of a tube of the developer in 4 ounces of water in the 



FIG. 161. Some darkroom equipment. At rear a large tray for fixing or 

 washing. At right, graduate. At its left trays for developing, the box of develop- 

 ing powders, with two tubes on table still farther to the left. At extreme left a 

 plate holder with slide partly removed. At its right are print frames, one showing 

 its back, the other with negative in place ready to print. 



graduate. The tube contains at one end the developer and at 

 the other some chemicals that speed up the rate of development. 

 As you hold the tube in hand to read the label, the developer is 

 at the right-hand end. Open this end first and pour the powder 

 into the water as you stir with a glass rod. Then open the other 

 end of the tube and pour in the chemicals while stirring. The 



