Comments on the pros and cons of a statue or professorship in memory of John Dalton. Would favor a professorship. Thinks the rules should be amended. Knows a good man for the position.

Will distribute the prospectuses of LH's book as desired, but regrets he will be unable to subscribe for a copy himself as its price is too expensive for his means. Pleased to hear of his good health.

Tells WT about JH developing the thermographic paper which is susceptible to 'calorific' and 'chemical' rays of light.

The Physical [?] Committee is meeting the next day to deal with the question of establishing a magnetic and meteorological observatory. JH [Chair of the Physical Committee?] cannot attend the meeting and sends his supportive, but cautioning, comments.

Supports the remeasurement of N. L. Lacaille's geodetic arc in South Africa, giving a number of reasons for his support.

A note to accompany some letters being returned to GA.

Comments on the operational and organizational details of the magnetic and meteorological observatories, and on the supervisory committee's [the Physical Committee of the R.S.L.] responsibilities.

Remarks on the significant increase in brightness of the star Eta Cygni, and comments on several other variable stars.

Extensive letter answering the many queries about nebulae raised by AH in his 1844-4-18 [letter contains notes made by AH].

Sends thanks and very high praise for AH's first volume of Kosmos. Also comments on a number of other astronomical matters.

Mother and baby [Margaret and Julia] are doing well; JH asks questions relating to the Grovers giving up the lease on JH's property at Slough.

Convey his thanks to the King for the Order of Merit. Regrets he did not see the King or AH when they visited London recently. Gives astronomical information.

Comments on JD's work in photography; JH goes on to talk about JH's ideas of 'chemical' rays of light.

Exchanging further information on several aspects of the photographic process [see RH's 1840-4-15].

Has not lately done much work in photography, except to work with paper treated with vegetable substances.

Has received a request from the Admiralty to order a new telescope for the Cape observatory; at the same time, JH has received an unsolicited offer of a lens. JH seeks advice and information from GA.

Both JH and his wife, Margaret, are very concerned about the health of Madame Gerlach, the aunt of NS. Details are provided.

A letter of even greater urgency about the very serious state of health of Madame Gerlach, the aunt of NS [see JH's 1843-10-20]. Madame Gerlach is living with the Herschels [as tutor? or governess?].

RH's experiments are extremely interesting and deserve to be pursued. Comments on experiments made by Michael Faraday and others relating to the formation of crystals in a magnetic field and the effect such crystals have on polarized light.

As JH has not heard from NS, he has arranged for Madame Gerlach to stay with Mrs. Mason, now living in part of JH's former residence at Slough. But under no circumstances can Madame Gerlach return to her duties with JH's family.