Sends papers for R.A.S. and A. J. Fresnel's papers. Modifies analogy of infinite pipes to clarify TY's hypothesis of three principal colors. Charles Babbage sent survey of Mont Cenis. Can JH find its barometrical observations?

Measurement of moon's diameter and distance. Expects JH will soon have 'official authority over me' and [Nautical Almanac]. Astronomers probably regulate sidereal clock by variable equinox because they cannot find a fixed one. Errors in JH's equinoctial time.

Errors in equinoctial time calculated by John Pond. Suggests limiting decimal places in value of equinoctial time to reflect this uncertainty. Making error uniform will make it awkward to alter future almanacs.

JH is correct, and TY's 'little man is wrong.' Moon's apparent angular motion increases as spectator moves closer.

Resolved puzzle about sidereal year, which needs better definition. Error between true and nominal positions prevents TY adopting 'equinoctial time' for chronology investigations.

Board of Longitude would approve providing Lieutenant Forbes with apparatus JH suggested. Inappropriate for any member to address Admiralty separately. Payment of expenses to committee members.

J. J. Littrow's paper in F. X. von Zach's April [Correspondence astronomique, géologique, hydrographique et statistique] is only 'a new hash' of [F. W.] Bessel and no improvement.

Send plan of furnace to TY or Michael Faraday before tomorrow's committee meeting.

Leaving for two weeks in Netherlands.