[The original has not been located. This is from the version read at the meeting of the Society of Arts in London on 11 May 1853 and published in the Journal of the Society of Arts, v. 1, 13 May 1853, p. 292.]
Lacock Abbey, May 10th, 1853.
Dear Sir,- I have great pleasure in replying to your question. The first person who applied photography to the solar microscope was undoubtedly Mr. Wedgwood, as appears by his paper in the journal of the Royal Institution for 1802,<1> hut none of his delineations have been preserved, and I believe that no particulars are known. Next in order of time to Mr. Wedgwood's, came my own experiments. Having published my first photographic process in January, 1839, I immediately applied it to the solar microscope, and in the course of that year made a great many microscopic photographs, which I gave away to Sir John Herschel,<1> Sir Walter Calverley Trevelyan, and other friends. The size of these pictures was generally that of a half sheet of writing paper, or about eight inches square. The process employed was my original process, termed by me at first "Photogenic drawing,"- for the calotype process was not yet invented. I succeeded in my attempts, chiefly in consequence of a careful arrangement of the solar microscope, by which I was enabled to obtain a very luminous image, and to maintain it steadily on the paper during five or ten minutes, the time requisite. From the negative, positives were made freely, in the usual way. The magnifying power obtained was determined by direct measurement of the image and the object itself, which gave for result a magnifying power of seventeen times in linear dimensions, and consequently of 289 in surface. The definition of the image was good. After the invention of the calotype process, it became of course a comparatively easy matter to obtain these images; and I then ceased to occupy myself with this branch of photography, in order to direct my whole attention to the improvement of the views taken with the camera.
I remain, dear Sir, yours very truly,
H. F. Talbot.
Mr. Samuel Highley, jun.
1. Sir Humphry Davy (1778–1829), chemist and Thomas Wedgwood (1771–1805), ‘An Account of the 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 n. 9, 22 June 1802, pp. 170–174.
2. The four examples of WHFT’s magnified lace known to have been owned by Herschel are three negatives, dated 1839 in WHFT’s hand; NMeM, Bradford, Schaaf 2250, 2274 and 2775, and one print of magnified lace, also dated 1839 in WHFT’s hand, Herschel collection at Oxford Museum for the History of Science, Schaaf 3767.