368 APPENDIX B 



Barometers. — The Goldsmith form of direct-reading aneroid is the 

 most accurate portable instrument and, of course, should be compared 

 with a standard mercurial at the last weather-bureau station. 



Thermometers. — ^A swing thermometer, with wet and dry bulbs for 

 determination of the amount of moisture in the air, and the maximum 

 and minimum thermometer of the signal-service or weather-bureau 

 type should be provided, with a case to protect them from injury. 



A tape measure with metric scale of measurements on one side 

 and feet and inches on the other is most important. Two small, light 

 waterproof cases could be constructed and packed with scientific in- 

 struments, data, and spare clothing and yet not exceed the weight limit 

 of flotation. In transit by pack-train these two cases would form but 

 one mule load. 



Photographic. — From the experience gained in several fields of ex- 

 ploration it seems to me that the voyager should limit himself to one 

 small-sized camera, which he can always have with him, and then carry 

 a duplicate of it, soldered in tin, in the baggage. The duplicate need 

 not be equipped with as expensive a lens and shutter as the camera 

 carried for work; 3MX4M is a good size. Nothing larger than 

 3K X SJ^ 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 3Ji x 4J4: 



One lens 4 or 4^^ 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 contain 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 dif- 

 ficulty 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 



