1090 Transactions of the American Instituts. 



the Andes where the thermometer is ' steady ' at zero, with three 

 mule-loads of chemicals and instruments, and ' Hardwick's Manual 

 and Practice.' 



" But badinage apart ; how photography may be best utilized for the 

 purposes of the traveler, it seems to me, is a problem worthy of 

 engaging the attention of the practical professors of the art. Unfor- 

 tunately, however, there are few of these professors who know all 

 difficulties which beset the traveler, especially in remote, savage, or, 

 half civilized countries; where, perhaps, neither house nor hut is to 

 be encountered for days and weeks, where the weather is fervid or 

 freezing, the earth overshadowed by forests, or overflowed by water, 

 or else desolate and dry ; where always, above all things else, trans- 

 portation is expensive, difficult or impossible to be had, and where 

 the baggage of the traveler requires to be reduced to a minimum. 



" The traveler does not expect to take fine pictures, to be exhibited 

 as among the highest achievements of photographic art ; but he 

 wants to obtain fair results, cheaply and rapidly. And to do this 

 he must have his apparatus compact, dispense with tents, be able to 

 get along, for a reasonable time at least, without water, and with the 

 least possible amount of that heavy and fragile material called glass. 

 He must also be able to do his whole work without assistants, who 

 are seldom to be had, or when had, are sometimes worse than none 

 at all. 



"But above all, he wants a manual, simple in language, clear in 

 direction, brief as a primer, which shall tell him what to do, and not 

 why anything is to be done. Many travelers have a certain knowl- 

 edge of chemistry, and most a fair knowledge of things in general. 

 But they seldom have the time or inclination to perfect themselves 

 in photographic chemistry. They want the instruments and the 

 materials, with plain instructions for their use. I have the reputa- 

 tion, throughout most of Central America, of being a great atid 

 almost infiillible medico or doctor. Until I went there I trusted my 

 health and life to my physician, and asked no questions, just as I 

 should trust my head to Saxony ; but I was going where there were 

 few physicians, if any, on a long and dangerous exploration, in a 

 strange tropical region, with its peculiar diseases. Well, what did I 

 do ? I went to Rushton & Clark, a otliecaries, told them where 

 I was going and what I was going to do, and asked them to fit me 

 up a medicine chest, with medicines and plasters, and other things 

 most likely to be required in case of -illness or accident, and to ^^vTite 



