6 Union St Glasgow
Augst 30 1842
Your remark that several persons producing the Calotype in London would injure each other, is just. I should like an exclusive license [sic] for London, or at most, not more than one rival:<1> I dont think that a license for any other city in the United Kingdom would be worth any thing at all. I contemplated doing the pictures on a large scale the size of life. I am doing the Daguerreotype in a room here, but suppose that I should require a place made on purpose for doing the Calotype; as I find that it requires double the time that I take for my Daguerreotype process. Is it your opinion that the Calotype pictures would be best made in sunshine through blue glass?<2> Of course one dark room would be sufficient for all the manipulations How long does it require to take a Calotype portrait on a dark day clouded with clouds so that you cannot see the sky at all one dense mass of dark clouds without any shape like a sheet of water drawn over the sky, or as if the sky was a slate roof? and will you please to state at the same time the artifycial [sic] circumstances, such as situation, time of the day, aspect, length of focus, diameter of aperture, and distance and whether one or two lenses are used
I am Sir Yours very respectfully
H. W. Treffry<3>
H. F. Talbot Esqr
1. One of the reasons that the Daguerreotype flourished was that there was intense competition between practitioners.
2. Virtually all photographic processes at this time were primarily sensitive to blue light. Some Daguerreian studios were glazed in blue, for while this cast a ghostly pall over the surroundings, it reduced the glare visible to the human eye and cut down on heating rays.
3. Although Treffry has yet to be positively identified, in June 1842 the partnership was dissolved of William Treffry, William Henry Treffry, and Samuel Bevan, of Wenlock Basin, City Road, London; engineers, boiler makers, and iron founders. This was the address that Treffry originally wrote from (see Doc. No: 04321). The daguerreotypist might have been a son or brother, or perhaps an intentional inversion of William Henry's name.