Sir J. Herschel

May 1851

Dear Sir

Some time ago you were mentioning to me a process of photography by which pictures could be changed from a negative to a positive state, and I suggested for it the name of Amphitype, ^<1> of which you approved. I wish to know whether you have anywhere published an account of that process, and given that name to it?

If you have done so, the name of course becomes limited and attached to your process; but if not, and if the name is still disposable, I am desirous of attaching it to a process entirely of the same character, but even more suitable to the name, since it is intermediate between the Daguerreotype process, and photography on paper, and partakes of the nature of both. I propose very shortly to publish an account ^<2> of this process which if I am not mistaken is a considerable step in advance of photography. I will content myself at present with saying that the pictures held in one light appear positive, in another negative – which justifies the name proposed to be given.

But the most remarkable thing is the astonishing celerity of the process, which will enable us I think to accomplish what has been so long a desideratum, a photographic portraiture of the lunar disk & mountains as seen in a large telescope. I am even in hopes that we may dispense with the aid of an equatorial clock movement, or that we shall ultimately perfect this or some similar process to that extent.

Believe me Dear Sir Yours very truly
H.F. Talbot

Lacock Abbey
Chippenham

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Notes:

1. See Doc. No: 04784.

2. See Doc. No: 06525.