SCIENCE IN THE INDUSTRIAL WORLD 



tically a whole day, although "this time could be 

 shortened by half in the case of such objects as white- 

 marble monuments." 



THE DAGUERREOTYPE 



This process was so exasperatingly near a really prac- 

 tical method of making pictures that Daguerre and 

 Niepce strained every nerve to bring it to perfection, 

 or at least to a stage of commercial practicality; but 

 after six years of ceaseless struggle, Niepce died, leaving 

 the riddle apparently as unfathomable as ever. Yet, 

 had he but known it, he was on the very threshold of 

 the discovery; and five years later Daguerre finally 

 accomplished what Niepce had missed by so narrow a 

 margin. In 1839, Daguerre announced to the French 

 Academy the process that was thenceforth to be famous 

 as the daguerreotype process, by which a camera image 

 could be reproduced by the action of light and chemicals 

 alone, and by a relatively short exposure. 



The announcement of this process created a sensa- 

 tion in the Academy. There was no doubting the evi- 

 dences of their own senses, and all the members were 

 apparently in accord in their expressions of admiration 

 and astonishment. Arago, the leading physicist of 

 France, spoke in glowing terms of the possibilities of 

 the new discovery, and made predictions as to its future 

 usefulness that have been more than fulfilled in recent 

 years. And as the French Academy had given the cue, 

 other learned bodies all over the world echoed its senti- 

 ments. Nor were the scientists the only persons to recog- 



[224] 



