PHOTOGRAPHY, SCIENTIFIC ASPECTS 



and improved his process until he was able to make 

 pictures on metal in many ways resembling the modern 

 tin-type, he sent an account of his discovery to the 

 secretary of the Royal Society of London, together 

 with some specimens of his work. But the actual 

 process by which the pictures were made was not 

 revealed in this document, and on this account the Royal 

 Society as a scientific body, although greatly interested, 

 could not publish it. 



Just at this time a fellow countryman of Niepce's, 

 whose name was later to be far better known in the 

 history of photography, became interested in the sub- 

 ject. This was Louis Jacques Mande Daguerre, a 

 scene-painter, who was famous at the time for his 

 handling of lights and shades, and whose attention 

 had been directed to the subject of photography by the 

 remarkable effects he was able to produce with light 

 projected through colored glasses. At that time he had 

 done nothing with the subject of " heliographic pictures," 

 as they were called, but when a letter came to him from 

 Niepce, in 1827, suggesting that a partnership be es- 

 tablished between them, he readily entered into such an 

 arrangement. 



The new firm was soon able to reproduce pictures of 

 various kinds on metal, and also upon glass and porce- 

 lain, but the process used was too complicated and te- 

 dious for practical commercial purposes. Nothing but 

 stationary objects in bright sunlight could be reproduced, 

 and then only after weary hours of exposure to a sen- 

 sitized plate in a camera. Ordinary landscapes re- 

 quired an exposure of from seven to ten hours prac- 



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