Compares actinometric measurements of radiation. Explains interest in total eclipse relative to actinometry. Discusses the possibility of making actinometric measurements by photographic means.
Showing 21–39 of 39 items
The Sir John Herschel Collection
The preparation of the print Calendar of the Correspondence of Sir John Herschel (Michael J. Crowe ed., David R. Dyck and James J. Kevin assoc. eds, Cambridge, England: Cambridge Univ. Press, 1998, viii + 828 pp) which was funded by the National Science Foundation, took ten years. It was accomplished by a team of seventeen professors, visiting scholars, graduate students, advanced undergraduates, and staff working at the University of Notre Dame.
The first online version of Calendar was created in 2009 by Dr Marvin Bolt and Steven Lucy, working at the Webster Institute of the Adler Planetarium, and it is that data that has now been reformatted for incorporation into Ɛpsilon.
Further information about Herschel, his correspondence, and the editorial method is available online here: http://historydb.adlerplanetarium.org/herschel/?p=intro
No texts of Herschel’s letters are currently available through Ɛpsilon.
Compares actinometric measurements of radiation. Explains interest in total eclipse relative to actinometry. Discusses the possibility of making actinometric measurements by photographic means.
Proposes meeting times in town. Suggests that JF observe the upcoming total eclipse astronomically. Agrees with JF's seemingly 'cold &c' circular on scientific partnerships, while regretting that it needed to be written.
Explains efforts at using a makeshift apparatus for 'fixing the spectrum.' Discusses current confusion and ultimate hope surrounding JF's meteorological recommendations. In a postscript, notes observations of meteors in Persei.
Instructions for preparing liquid for the actinometer. Describes 'very strange' experiments on the spectrum as well as an 'unusual' cloud formation.
Requests papers relative to a preface to the catalogue of [N. L.] Lacaille's stars, so that the catalogue may be printed.
Believes JH expressed support for pension for surviving child of Thomas Henderson. Comments on this, stating his own view that she is already well provided for.
Thanks for medal of the Royal Society of Edinburgh.
Comments on JH's Treatise Astr. in the Cabinet Cyclopaedia, mentioning its continued publication, misstatements he wishes to correct, and his addition of A. de Gasparis's newly-discovered planet [Hygeia].
Outlines theory behind and method for preparing thermographic paper, which allows observers to determine 'what share each ray of the spectrum bears in producing the observed total effects.'
Sets up approximate meeting time, depending on his family's timely departure to Antwerp, with JF at the R.S.L. apartments.
Requests information about actinometers in JF's possession, and provides further information regarding their use.
Believes all actinometric measurements made are useless because they did not take into account the rate of expansion of the liquid, which is not constant.
Thanks JF for second edition of work on the Alps. Praises first edition.
On the preparation of paper to exhibit a thermal spectrum.
Hopes to add JF's name to B.A.A.S. Meteorological Committee, and to see JF at Cambridge meeting of the committee.
[Responding to JF's 1849-11-23], JH cautiously discusses various considerations bearing on the idea of sending an astronomer and a large reflecting telescope to the Cape.
Protesting about the refusal of the Royal Society of Edinburgh to publish Thomas Brisbane's magnetic observations; hopes it will be reconsidered. Thinks JF's theory on glaciers has good points, but comments on some of its shortcomings.
Asks for details of several actinometers.
Agrees that it would be desirable to make further observations at the Cape, but foresees difficulties, especially liaison with the Astronomer Royal at the Cape.