Regarding the absence of his own name from the candidates list for the R.S.L.; thinks there is a clique working against him.
Regarding the absence of his own name from the candidates list for the R.S.L.; thinks there is a clique working against him.
Has been requested by the Editor of the Quarterly Journal of Science to write a paper on JH and modern astronomy. Would like JH's sanction, and also a few notes on the most important aspects.
Is grateful for his letter and will study the memoirs to which he refers. The Editor would also like a photograph; can JH oblige?
Has a work on Elementary Physics almost through the press; it is intended for the young. Hopes to construct an instrument to measure amount of chemical action in the solar rays. Would like JH to speak to a member of the Government about a position RH would like.
Is anxious for some means to be developed to get a measurable quantity [preferably by weight] from the action of a beam of light on a surface. JH has been experimenting in photography with 'flouric' compounds.
Thanks RH for a sample of Daguerreotype paper. Comments on some aspects of the action of 'thermic' rays and 'chemical' rays in photography.
Sends more copies of prospectus of RH's book (Poetry of Science) for JH to distribute.
Does not believe JH can help RH in some delicate matter. JH talks about photographic chemistry, including passing on information from A. C. Becquerel.
Does not know anywhere that such processes as RH uses are used for registry work, although the idea is frequently raised.
Thanks for RH's paper on mineralogy. JH has explored use of mercury together with iron in photography.
Thanks RH for his 'extensive and instructive view on the present state of photography.' Found many interesting results in experimenting with vegetable substances. Surprised by RH's discovery that bi-chromate of potash is a photographic substance; JH nearly achieved this result.
Some information about Charles Piazzi Smyth. JH needs information about some of RH's photographic paper, which JH has tried but without success.
Believes that the operative rays in JH's thermographic process are neither 'calorific' nor 'thermal'.
Clarification of priority to the prismatic analysis of the Daguerreotype photograph; comments on the location of a limiting diaphragm in a camera obscura.
Intrigued by RH's experiments with photographic papers; will buy six sheets of RH's specimens. Admits having conducted numerous experiments himself and asks to include some of RH's results in a forthcoming paper on the subject.
Will forward RH's paper to the R.S.L.; intrigued by RH's results using mercury vapor to produce the image on exposed paper.
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.
Sends RH a packet of photographs with a description of each type.
Some comments about photographic processes and about RH's observations of the heavens [see RH's 1843-3-24].
Read John William Draper's papers; although he believes that Draper's instruments are inconsistent, JH feels that they are still important because they are measurable. Decries [L. F.] Moser's skepticism of photography's value, calling it a 'blindfolding to some of the most interesting physical relations that have ever been discovered.'