4 Atholl Crescent
I am at present residing in Edinburgh –
All I can send you <1> are some impressions taken from my engraved steel plates. These I send by todays post.
N. B. galvanism is not employed in my process <2> – Of course however the gelatine image, being in basso rilievo, <3> can be Electrotyped – Mr Pretsch <4> has done this
H. F. Talbot
1. This is the reply to Doc. No: 07522.
2. In October 1852 Talbot had taken out a patent [no. 565, 29 October 1852; detailed specifications filed 29 April 1853] for Improvements in the Art of Engraving. This was a contact process using gelatin sensitised by potassium bichromate, on a steel plate, the resultant image then being etched into the steel. For a detailed description, see H. J. P. Arnold, William Henry Fox Talbot: Pioneer of Photography and Man of Science (London: Hutchinson Benham, 1977), pp. 273–75.] However, in April 1858 Talbot took out another patent [no. 875] for an improved process that he called photoglyphic engraving. It might have been this process that is referred to here.
3. low relief
4. Paul Pretsch (1808–1873), Austrian photographer & inventor; founder of the Photogalvanographic Company.