Questions JH's conclusion that Board of Longitude has power to interfere in Admiralty operations. Disagrees that Nautical Almanac errors are serious. Compares them to tables of Charles Hutton, F. X. von Zach, and H. C. Schumacher. When will TY receive Charles Babbage's table?
Encloses note from Sir John Barrow refusing scientific instruments and objecting to using barometers. Supplying cameras and sextants to Admiralty's marine survey is not interference by Board of Longitude. Sent JH's expenses to Edward Sabine; has no further word on subject. Encloses Mr. Stewart's note about damages at Wrotham.
[Board of Longitude] must answer to Parliament, not to public opinion. Do not contest the system. Order pocket sextants; they and barometer will be sent to Captain [Richard] Copeland. Knows how JH feels about expenses sent to Edward Sabine, but please write receipt and send it to TY within week. Will write directly to Charles Babbage for tables.
Suggests change in JH's table of refractions. Possible error in John Pond's reductions [illustration].
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.
Resolved puzzle about sidereal year, which needs better definition. Error between true and nominal positions prevents TY adopting 'equinoctial time' for chronology investigations.
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.
'Our volume is nearly ready.' Problem dating vernal equinoxes before Christ's birth.
Board of Longitude will accomplish nothing by meeting before T. M. Brisbane comes to town, but TY suggests informal discussion, either at TY's or Henry Kater's.
Henry Kater not well [enough to travel] and requests committee meet at Kater's house. TY urges JH to verify W. H. Wollaston's measurement of refraction before republishing JH's essay. Diagrams Christiaan Huygens's principle of refraction. TY is making forms of aplanatic lenses.
Hopes JH will stay for Sunday dinner at TY's before JH visits Dr. Litten. If so, please invite T. M. Brisbane and Francis Baily to join them. Writes formula TY discovered for discontinuous spectra. TY can now communicate with H. W. M. Olbers and T. J. Seebeck via H. C. Schumacher.
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.
Abandons TY's argument on Mr. Roberts's object glass. Asks JH's help in understanding A. J. Fresnel's calculations of diffraction and Josef Fraunhofer's discontinuous functions.
T. M. Brisbane is in town. Can JH meet him? JH's computations of definite integrals are simpler, more direct than P. S. Laplace's and more conclusive than Leonhard Euler's. Comments on W. H. F. Talbot's letters demonstrating Josef Fraunhofer's theorem.
Sudden demolition of Board of Longitude. TY is left as superintendent [of Nautical Almanac]. Notes quality of J. F. Encke's almanac for 1830. Should English compete with German astronomers, or discontinue almanac supplements? TY's paper on 'Astronomical Chronology' in W. T. Brande's [Quarterly Journal of Science and Art] illustrates JH's equatorial time.
Encourages TY to publish 1829 supplement to Nautical Almanac. JH originally proposed supplement to introduce improvements that would bring N. A. to be like Encke's Ephemeris. That is all ended now. English are dropping behind French and Germans in science. JH refuses to accept money from government 'which treats its agents so cavalierly.' Reduction of Parramatta [Australia] observations. Did not see TY's paper in W. T. Brande's [Quarterly Journal of Science and Art], but objects to substitution of true for mean equinox.
Will not hold JH responsible for accuracy of William Richardson's computations. No instructions yet from Admiralty about Nautical Almanac, which goes to press soon. TY will insert JH's equinoctial time. Notes two works by A. F. C. Kollman on harmony and [Beck] on 'thorough-bass.'
Feels responsible for JH refusing to accept Navy's £25 reimbursement. Used JH's [equinoctial] time [in Nautical Almanac supplement], but with different notation. Disagrees that England's scientific reputation depends upon its government. William Richardson is justified in continuing work of late Board of Longitude. Reports meeting in Paris with Jacques Babinet and François Arago.
Problems calculating sun's mean longitude due to movement of perigee. Questions S. D. Poisson's value for sidereal year.