392 Appendix B 



for fixing also. A nest of tanks would be a convenience; 

 one tank should be kept separate for the fixing-bath. As 

 suggested in the Kodak circular, for tropical develop- 

 ment a large-size tank can be used for holding the freez- 

 ing mixture of hypo. This same tank would become the 

 fixing tank after development. In the rainy season it is 

 a difficult matter to dry films. Development in the field, 

 with washing water at 80° F., is a patience-trying opera- 

 tion. It has occurred to me that a small air-pump with a 

 supply of chloride of calcium in small tubes might solve 

 the problem of preserving films in the tropics. The air- 

 pump and supply of chloride of calcium would not be as 

 heavy or bulky as the tanks and powders needed for de- 

 velopment. By means of the air-pump the films could be 

 sealed in tin tubes free from moisture and kept thus until 

 arrival at home or at a city where the air was fairly dry 

 and cold water for washing could be had. 



While I cordially agree with most of the views ex- 

 pressed by Mr. Fiala, there are some as to which I dis- 

 agree; for instance, we came very strongly to the 

 conclusion, in descending the Duvida, where bulk was of 

 great consequence, that the films should be in rolls of 

 ten or twelve exposures. I doubt whether the four-barrel 

 gun would be practical ; but this is a matter of personal 

 taste. 



