Appendix B 391 



not be equipped with as expensive a lens and shutter as 

 the camera carried for work; 3j4 x4j4 is a good size. 

 Nothing larger than 3>^ x 5}4 is advised. We carried 

 the 3A special Kodak and found it a light, strong, and 

 effective instrument. It seems to me that the ideal form 

 of instrument would be one with a front board large 

 enough to contain an adapter fitted for three lenses. For 

 the 3>^x4j4: 



One lens 4 or AYz focus 



One lens 6 or 7 focus 



One lens telephoto or telecentric . . 9 to 12 focus 



The camera should be made of metal and fitted with 

 focal-plane shutter and direct view-finder, 



A sole-leather case with shoulder-strap should con- 

 tain the camera and lenses, with an extra roll of films, all 

 within instant reach, so that a lens could be changed 

 without any loss of time. 



Plates, of course, are the best, but their weight and 

 frailty, with 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 



