Has not lately done much work in photography, except to work with paper treated with vegetable substances.
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Has not lately done much work in photography, except to work with paper treated with vegetable substances.
Will do all in his power to ensure that MM receives copies of the publications relating to the Fixed Observatories. Does not think MM could have seen a copy of JH's paper on photographic action when he wrote the notice in Annales de chimie. Comments on this paper and more recent experiments in this field.
Advice for standardizing observations, to be given to the Physical Committee of the R.S.L.
Unable to give any specifics concerning Louis Jacques Mandé Daguerre's new photographic process. Discovered that old paper specimens produced a much better representation of the spectrum in its natural colors than those obtained at the date of JH's paper; these results are 'light on a dark ground,' which makes JH more hopeful that colored photography will someday be perfected. Has experimented with vegetable substances.
A note to accompany proposals for the Standards Commission to consider [see GA's 1841-2-17]; twenty pages of proposals are appended.
Writes to announce the birth of daughter Amelia, and to assure RA that both JH's wife, Margaret, and new daughter are doing well.
It will be difficult for JH to get away to Collingwood as planned as discussions [?] are slow; some family news.
Explains 'discordances' as contraction of damp paper. Use 'Engraved Squares' to avoid this error. Possible error in barometer observations from Montreal. Diurnal 'undulation' appearing in data. American observations arrived, may fill 'missing intervals.' Keep record of expenses incurred. Postscript on color variation in stars.
A portable magnetometer purchased by the B.A.A.S. is now available as a loan for use in magnetic survey of British Guyana.
Notes interest expressed by Macedonio Melloni in meteorological observations. Urges that R.S.L. Council give its attention to the mass of meteorological observations that have accumulated.
Returning some papers that should have been returned earlier. Hopes all are well.