Letter from Sir John F.W. Herschel, Collingwood, Hawkhurst, to the Secretary of the Physical Committee of the Royal Society Offering an instrument for the investigation of the solar spectrum with enclosed photographic specimens of the Physical Committee's inspection. Herschel requests an amount above £50 or £60. [Enclosures not present.] [Recommended sum of £100, suggested by the Committee, to be paid out of the Donation Fund, as agreed by the Council.] 1 June 1842