302 The Dawn of Light Printing. [Jtily, 



diameter of the casement. I read in the Abbe Nollet* that 

 in order to reproduce a larger number of distant objects, a 

 lens possessing a very long focus must be used, and a second 

 glass must be fitted into the tube carrying the lens. If you 

 desire to preserve the impressions, although they are scarcely 

 worth the trouble, you have merely to place them between 

 two sheets of grey paper and put them into a book. My 

 future investigations will be conducted with a three-fold 

 object — 



"i. To obtain a clearer definition of the reflected image. 



"2. To transpose the tints or shadows. 



"3. To fix the tints, an operation which is by no means 

 an easy one." 



It is not definitely stated what is the nature of the exciting 

 chemical employed, but from the hint given there can 

 scarcely be a doubt of its being nitrate of silver. In any case, 

 however, we have here absolute proof that Niepce, working 

 alone in a small out-of-the-way provincial town, far from all 

 scientific resources, and ignorant, may be, altogether of the 

 preliminary researches of Wedgwood and Davy, made 

 several years previously, succeeded in catching up and 

 securing the images reflected in the camera. Of course, as 

 we know very well, such images were not permanent, and 

 required to be fixed before their durability for any lengthened 

 period could be ensured; but, after all, it must be remembered 

 that even at the present day the imperishability of silver 

 prints is still an unsolved problem. But Niepce's success 

 was not yet complete ; from the very first it is apparent 

 that he entertained a remarkably clear notion of what 

 was necessary to elaborate a process of this nature, and 

 the precise and orderly manner in which he arranged his 

 ideas and conducted his research, catching hold of his 

 subject as it were at the right end, could not but fail in 

 bringing him to sound and speedy conclusions. After having 

 succeeded so far as to hold fast the shadow, the next task 

 he set himself to accomplish could scarcely have been 

 better chosen as a sure means of progressing on his way. 

 In his next letter, dated but nine days afterwards, he tells 

 how fortunate he has been in his later efforts ; and, indeed, 

 this commuication reads more like the words of an en- 

 thusiastic amateur photographer of the present day, rather 



* L'Abbe I. Antoine Nollet, Member of the Academie des Sciences ; born 

 1700, died 1770. He occupied himself chiefly with the study of ele&ricity, 

 and was distinguished as an accomplished le&urer and exponent of the 

 physical sciences. His principal work was entitled "Lecons de Physique 

 Experimentale," in six volumes, published in 1743. 



