1871.] The Dawn of Light Printing. 301 



all, the problem of fixing the colours — but with steady 

 perseverance and much patience I hope to succeed in 

 working out my designs. That which you foretold has 

 happened; the ground of the picture is black, and the 

 images are white; that is, lighter than the ground. I believe 

 a method of obtaining pictures by this means might be made 

 use of, and I have seen engravings of a similar description. 

 It may not be impossible to change the disposition of the 

 colours, and I have made some experiments in this direction 

 which I am anxious to verify." 



From the above we see that Niepce had formed a very 

 excellent idea as to how an image could be secured, and 

 was truly in a fair way to solve the mystery of printing by 

 light. At the same time he was aiming at far too much 

 when he sought to secure the colours themselves, and not 

 merely their impression upon some sensitive material. His 

 progress in heliography was, however, extraordinarily rapid, 

 for we find from a letter written on the 19th of May, 1816, 

 that he had undoubtedly succeeded in securing an image of 

 some kind in his tiny apparatus. He does not, however, 

 seem to have been much struck with the wonderful nature 

 of his results, for he alludes to them almost incidentally : — 



" I hasten to reply to your letter of the 14th, which was 

 received the day before yesterday, and with the contents of 

 which we were much pleased. I write on half a sheet of 

 paper only, as mass this morning, and a visit to be made 

 this evening, leave me but little time ; besides, I have to 

 enclose two pictures taken by my process, and it is necessary, 

 therefore, that I should not increase the weight of my 

 letter too much. The smallest image was obtained in the 

 ring-box, and the other from the medium-sized camera of 

 which I spoke some time since. You will be able to judge 

 of the effect better by placing yourself somewhat in the 

 shade, and holding up the pictures placed upon an opaque 

 body against the light. A picture of this description is> I 

 believe, subject to alteration after a time, as although proof 

 against the action of light, the reaction of the nitric acid in 

 its composition will have the effect of destroying it ; it is 

 possible, also, that the prints may become damaged by 

 shaking and jolting during, their transport. This is, of 

 course, merely an experiment, but if the materials were 

 rather more sensitive (as I hope to obtain them), and, above 

 all, if the order of the shadows were inverted, the illusion 

 would, I think, be quite complete. The two pictures were 

 made in my operating room, and the field is merely the 



