Has written a letter to Lord John Russell outlining the case of Andries Stockenström. Does not wish to become involved in Cape politics or the affairs of the Anti-Slavery Society much as he appreciates their importance.

Has been applying his mode of calculation for the barometrical heights for the years 1815-23 and sent the results to the R.S.L. As JH may not see them he sends a few comments on them. Would like a suitable colleague to share his labors.

Encloses some more calculations of height by means of the barometric mean temperature. Comments on these. Staying at Ackworth until April.

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.

Would like JH's account of his own method of fixing a photograph as noted in his memoir. Singular phenomenon of the Daguerreotype. Hopes to produce a photographic paper to equal the silver plate before the month has expired. Will let him know when his process is complete.

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

Is grateful for the handsome manner in which JH has acknowledged RH's work. Would be willing to prepare a memoir for the R.S.L. Does Louis Daguerre's patent affect RH's manufacture of photographic papers? Has not studied the bromnets so far, but has studied the effects of bromine on plates. Comments on his results.

Sends his paper for communication to the R.S.L. Will send some more examples later as his camera has developed a defect.

Returns the photographic drawings of W. H. Fox Talbot with many thanks. Fears for their permanence. Has produced similar pictures himself acting on bromide of silver with hydrocholoric acid. Has had trouble with his periscope lens.

Was gratified to receive his memoir and to find many of his doubts corrected by JH's experiments. Hoped to enclose some sulphuretted papers but the chemicals went astray in the post. Intends to follow JH's example and precipitate a glass.

Is grateful for the suggested emendations to his paper. Comments on the action of iodine on silver and its oxide. When can he expect publication of his paper? Has noted a peculiar property in the calorific rays when copying engravings. Encloses some Daguerreotype papers.

Feels unable to become a member of the new society proposed by Halliwell, but wishes it well.

Arrived in England two days ago after a tedious voyage. Would like to visit JH. Off to Scotland next week. Called at the Colonial Office and had a friendly reception. G. T. Napier's dispatch has been received.

Is puzzled by JH's use of a word in his volume on astronomy; can he explain its meaning. Points out further misprints. Hopes JH will edit the works of his father [Sir William Herschel].

Would like permission to make a copy of one of the plates from JH's book on astronomy in order to print it in one of his own works intended for amateur astronomers.

Hears that JH is to be one of his parishioners. Outlines the local educational establishments. Should be grateful to know if JH would be subscribing towards their upkeep.

Indicates travel plans, including a visit to FB, with a side trip for business to Slough. JH comments on some astronomical observations he has received.

Sends two lithographs. Has seen the Archbishop and expects to launch his scheme with the approval of the leading politicians.

Is not well and is planning a holiday. Will be in the vicinity of Hawkhurst next Saturday and would like to visit JH.