Octr – 4th – 1843. –
I have received your favor of the 30th Ultimo <1> and now proceed to such further explanation as may enable you to form a more accurate opinion upon the subject. –
The Material proposed to be used consists of Sheets or pieces of Horn chiefly used for Lanthorns, and fulfils in an eminent degree the conditions you have annexed to its utility, being far more transparent than either paper or ivory, which led me to consider it better adapted for the proposed object than any thing else, for the light penetrating so completely through it would I imagine imprint a perfect image more vividly and strongly than by any other means, & which if placed undermost when fixed into the frame would shew through the transparent surface & the air being entirely excluded, it would be rendered more durable and less liable to injury. –
I presume there would be no difficulty in saturating it with the necessary preparation, as it easily imbibes water when immersed in it, which renders it soft and pliant, hardening again when exposed to the air, or placed between two warm metal plates.
I have enclosed four pieces of Horn for present experiment of small size, but they can be had larger, say about 10 by 7 inches, two pieces are unpolished, & the other two polished which is done by friction with the hand and Rotten Stone, and can be more highly finished than this if more pains be taken. –
As it is possible that more important results may arise than are at present contemplated, I should wish this communication to be considered confidential, and when you have completed the requisite experiments I shall esteem it a favor if you will forward me a specimen of the result, & I shall at any time be happy to offer any further explanation that my knowledge of the article may enable me to suggest.
I remain Sir Yr Obt Servt –
131 Whitechapel. –
PS – Could you not include this among the improvements in the Specification of the Patent you have recently taken out? <2>
1. Letter not located.
2. WHFT, ‘Photography’, No. 9,753, 1 June 1843. England's somewhat arcane patent system was a frustration to WHFT. What Burnell was suggesting was to take advantage of the fact that an inventor had several months to fully specify his patent after taking it out. That was a conern shared between WHFT and Sir John Herschel about Louis Jacques Mandé Daguerre. See Doc. No: 03932 and the discussion in Larry J Schaaf, Out of the Shadows: Herschel, Talbot, & the Invention of Photography (London: Yale University Press, 1992), p. 88.