J. H. Bolton Esq
Lacock Abbey
Dr Sir
With respect to the facts & dates connected with this invention, some of them are as follows, which may be useful to you for occasional reference.
Sir H. Davy and Wedgwood first discovered, in 1802,<1> that a sheet of paper could be made sensible to light, and that thus a leaf or small object placed on the paper would, by protecting the paper from the light, leave its own image or shadow. These images were all negative. Davy & Wedgwood tried in vain to fix these images. After a long course of experiments they abandoned the attempt as hopeless – It had occurred to Davy to try if it were possible in this way to obtain an image of a distant object by means of the Camera Obscura, But he states the attempt to have ended in entire failure, for that no length of time sufficed to obtain any result whatever.
These enquiries were not followed up by anybody, and they were in fact almost entirely forgotten. For my part I never heard of them till long after the commencement of my own researches – In 1834 I discovered, or rather rediscovered, the art of photography on paper, and after some difficulty I succeeded in fixing the images. [illegible deletion] Having done so, I proceeded to obtain positive images from these negative ones by transferring them to a second sheet of sensitive paper, by the agency of light. This was of course impossible to do, so long as the first obtained or negative images could not be fixed – I was thus the first discoverer of positive photographic images. This was in 1834. In the next year 1835 I succeeded in obtaining satisfactory views of buildings & other distant objects with a Camera Obscura, which produced a degree of astonishment in my own mind, and in those of my friends, to whom I showed it, which I shall never forget. The reason why I was successful in this attempt was that my paper was a good deal more sensitive than what Sir H. Davy had obtained – Still it was not sufficiently sensitive, for the smallest views took I think 10 minutes or a quarter of an hour, & large views 2 or 3 hours. – Not being able to attain to greater sensitiveness, I resolved to publish the results already obtained, but before my memoir was ready to be sent to the Royal Society, <2> Daguerre suddenly announced at Paris in January 1839 his discovery of the art of photography–<3> I immediately published my method in 2 memoirs dated 31st January & 13 Febry 1839.<4>
[in hand-drawn box:] Sheet 2
On the other hand Daguerre did not publish his method till the month of August following, but kept it a profound secret, & all sorts of conjectures were made throughout Europe respecting it. I had discovered myself in the previous year 1838 that a silver plate exposed to iodine vapour, becomes sensitive to light, but I did not imagine this to be Daguerre’s secret, being misled by M. Arago's<5> assertion made to the Institute, viz. that Daguerre’s plates were exceedingly sensitive, which I knew my iodised Silver plates were not; The fact is that their great sensibility remained unknown to me, being ignorant of the process of exposing the image to the vapour of mercury by which most ingenious proceeding Daguerre educed or brought out the latent image.
Having exhibited my pictures at the Evg meetings of the R. Institution <6> and Rl Society (Jany 1839) I immediately sent an account of the discovery to the Institute at Paris, and I refer you to the Comptes Rendus <7> of that learned body for a curious account of the Sitting of the Academy, <8> at which my Communication was read. Many members declared that it must be a hoax. M. Biot <9> however declared that he knew me, and that I was un homme serieux, <10> & that he was confident it was no hoax. Mr Arago then declared that at any rate it was too late, because M. Daguerre had already acquired un titre académique, that is, placed his invention on record by sending it to the Academy. – It turned out however that my invention was so different from Daguerre’s that there could be no question of priority between them.
Notes:
1. Sir Humphry Davy (1778–1829) and Thomas Wedgwood (1771–1805). Davy published ‘An Account of a Method of copying Paintings upon Glass, and of making Profiles, by the Agency of Light upon Nitrate of Silver. Invented by T. Wedgwood Esq. With Observations by H. Davy’, Journals of the Royal Institution, v. 1, no. 9, 22 June 1802, pp. 170–74.
2. Royal Society of London.
3. Louis Jacques Mandé Daguerre (1787–1851), French artist, showman & inventor.
4. WHFT, Some Account of the Art of Photogenic Drawing, or the Process by which Natural Objects may be made to Delineate Themselves without the Aid of the Artist’s pencil. Read before the Royal Society, January 31, 1839 (London: R & J E Taylor, 1839).
5. Dominique François Jean Arago (1786–1853), French physicist, astronomer & man of science.
6. Royal Institution, London.
7. Comptes Rendus hebdomadaires des séances de l’ de l’Académie des Sciences.
8. The Académie des Sciences.
9. Jean-Baptiste Biot (1774–1862), French scientist.
10. a responsible individual; a man of probity