Thanks CS of Gray's Inn for being willing to introduce JH to Mr. Clift.

On behalf of the Astronomical Society, JH thanks JD for a copy of JD's Histoire de l'astronomie moderne. JH tells JD about an interesting Arabic manuscript relating to the history of astronomy at Cambridge University, which JH will have copied for JD. In a postscript dated 15 June, JH apologizes for problems encountered in shipping printed material to JD.

Has received his communication via Gilbert Elliot (2nd Earl of Minto). Comments on the chances of [J. C.?] Schenck succeeding in business in England.

Thanks him on behalf of the Astronomical Society for his Histoire de l'astronomie moderne. Gives details of a paper on Arabic manuscripts in the Cambridge Philosophical Transactions. Have D. F. J. Arago and J. N. Nicollet received his letter?

Sends a copy of Volume 1 of the Transactions of the Astronomical Society, and makes arrangements for future volumes.

Received MB's notice that JH was appointed fellow of Saint John's College. Will visit Cambridge if William Herschel's health permits.

Discusses the pros and cons of GE's proposal that [J. C.?] Schenck, a Swiss maker of optical instruments, set up a business in London. JH is not sure that JH ascended Mt. Rosa, but is certain of JH's barometric reading. Interested in GE's method of estimating air temperature.

Requests corrections on a paper JS was publishing with JH. Urges JS to use less excessive language.

Thanks for the publications sent; lists materials JH is sending JL. Asks about quality of Josef Fraunhofer's large telescopes. JH read part of JL's letter of 2 Jan. 1822 at Astronomical Society meeting. Discusses proper motion of sun, JL's work on latitude of the pole star, observatory clocks, micrometers, and the Cambridge Observatory.

Examine reflecting theodolite by [?] Schenk, now at Edward Troughton's. Arrangements for Madeira expedition. James South is willing to make observations there. 'Bowdich (the African)' is now at Teneriffe or Madeira and needs employment. William Herschel's health.

[Responding to JS's letter dated 1822, i.e., #655,] acknowledges receipt of mail. Regrets delay but wished to examine the differences in electrical results between [J. W. A.] Pfaff and JH. Remains certain about results and request that this letter remain 'private.'

Has had a letter from the Secretary of the Dijon Academy offering him and CB the title of Non-Resident Associate of the Academy. Is there any chance of seeing him in the near future?

JH and James Grahame visited [Jan van den] Bosch's agricultural colony in Frederick's-Oort for 2,400 urban itinerants. Leave tonight for Haarlem, Hague, and Rotterdam.

Accompanies a paper JH was submitting to the Royal Society of Edinburgh. Discusses motion of light rays in Apophyllite and various optical writings of DB.

Sends JH's 1823 paper 'Absorption of Light by Coloured Media' to Royal Society of Edinburgh. Approves DB's illustration of polarized light in mineral apophyllite. Corrects DB's quotation from JH's letter regarding crystals observed on Mont Blanc.

Sends payment for packet of books.

Invites RJ to meet James Grahame, who is joining JH for trip to Netherlands. Return Éphémèrides du citoyen directly to Grahame. Describes return to Cambridge by JH, George Peacock, and William Whewell after their visit with RJ at Brasted. JH's sketch of Brasted Church. Alludes to [death of Grahame's first wife and oldest daughter].

Query regarding the construction of a model of a machine for CB. CB's letter to Humphry Davy about his engines. He will be visiting the Netherlands shortly. P. S. Laplace has sent him details of his recent researches into gases. Hopes the family are well after their recent visit to Devon.

Encloses table of star declinations for 1815 and 1820, received from F. W. Bessel, who used different meridian circles for each year.

Orders lithograph of enclosed letter and tables for Astronomical Society.