OUTFIT FOR TRAVELLING 359 



difficulty of handling, rule them out of the question. The roll film 

 is the best, as the film pack sticks together and the stubs pull off 

 in the moist, hot climate. The films should be purchased in rolls 

 of six exposures, each roll in a tin, the cover sealed with surgical 

 tape. Twelve of these tubes should be soldered in a tin box. In 

 places where the air is charged with moisture a roll of films should 

 not be left in a camera over twenty-four hours. 



Tank development is best for the field. The tanks provided for 

 developing by the Kodak Company are best 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 

 development a large-size tank can be used for holding the freezing 

 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 operation. 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 development. 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. 



AVhile I cordially agree with most of the views expressed by 

 Mr. Fiala, there are some as to which I disagree ; for instance, we 

 came very strongly to the conclusion, in descending the Diivida, 

 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. 



