31st Jany 1874
I have undertaken to give a Friday evening lecture at the Royal Institution – the 20th of Feby <1>– Will you take the trouble to let me know whether you ever lectured there on the calotype process – for I have an impression that this was so – I was working the Calotype process <2> in 1844, and believe that some of my information was derived from the lecture I believe I heard.
Kindly tell me also the date of the publication of your Calotype process
I am Dear Sir Yours faithfully
W. H. Fox Talbot Esqre F R S
1. The Royal Institution, London. Heath's lecture was "On the Autotype and other Photographic Processes and Discoveries," Notices of the Proceedings...of the Royal Institution of Great Britain, v. 7, 1874, pp. 220-226.
2. Although the first public revealing of WHFT's photogenic drawings was at the Royal Institution on 25 January 1839, he never lectured there on photography. See Doc. No: 02742, which is WHFT’s reply to this letter.