TALBOT1570

Dear Sir/

My friend M^r Hussey ¹ for whom I requested you to order the apparatus from Mess^rs Utzschneider ² has sent me the following list of what he expects

2 Rectangular Prisms of Flint glass 0ⁱⁿ·5 square

1 Rectangular D^o – 1ⁱⁿ·2 square

1 Equilateral Prism

2 Lenses 50 or 60 feet focus the least 3ⁱⁿ diameter.

3 Achromatic Object glasses 2ⁱⁿ diameter & under 12ⁱⁿ focal length

15 Plano convex Lenses, of 2, 1, 0·75, 0·5, 0·25, 0·1, 0·05, 0·03, 0·025, 0·02, 0·0166, ¹/₇₀, ¹/₈₀, ¹/₉₀, ¹/₁₀₀ inch focus

15 D^o D^o Plano concave

“Two or three other things” he adds “were mentioned but I cannot at this moment find the memorandum.” Besides these I have some recollection of having got M^r Hussey to include in his list some rectangular prisms for myself, but I am even worse than M^r H. for I not only cannot find the memorandum, but I can no how call to mind what it was I wanted.

I am at length bringing my article on “Light” ³ to a close and shall send you a copy as soon as it is complete

I should like very much to possess one of the 5 or 6 inch object glasses of that manufactory, but I really have a fancy to mount it myself– Have you any idea of what their present price for such a one would be, and whether they would furnish it alone, or at least with only the tube – & eyepieces & an illuminated wire micrometer? for as to their equatorial stands, I don’t like them, & one can get it put on a polar axis as well here as at Munich. but I have a different contrivance altogether in view.

I remain dear sir yours very truly
JFW Herschel

H.F. Talbot Esq^r
A.8. Albany
Piccadilly
London