Leaving for two weeks in Netherlands.

JH carried portable barometer by Edward Troughton and thermometer by Mr. Newman to Europe and compared these to instruments used by individual scientists and observatories. Reports results to Board of Longitude.

Thanks TY for books and for taking charge of [G. A. A.] Plana's plates. JH mentioned Eilhard Mitscherlich only when no other proposals came forth. Matter was left hanging. Assures TY that JH was not offended [see TY's 1824-11-21, i.e., #1075]. Regrets 'dilapidated state of scientific matters' in R.S.L.

Edward Sabine declares that R.S.L. is hostile to ES's interests. If ES makes future claim for compensation, JH wants TY's opinion in writing. Need to order four night glasses for Fairlight Station. Encloses letter from [Richard] Copeland.

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.

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.