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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.
Asks JH for information on the Beaufoy Clock owned by R.A.S., which is now missing. Requests JH to read R.A.S. Annual Report.
Has discovered William Herschel's memoirs in R.A.S. library; arranged and read them. Asks JH whether any copies exist so the originals can be checked for completion before binding. Questions JH on William Herschel's opinion of the nature of nebulae and boundaries of the galaxy.
Problems making actinometer observations during solar eclipse. Reports he did not observe the supposed planet Vulcan, but a fixed star. Sends micrometer observations. Describes shape of prominences.
Experiments with lens curvature and prisms. Wants to discover set rules for lens thickness-to-curvature ratio.
Forwards letter concerning 'solar bright particles' by W. R. Dawes. Inquires if diagonal solar eyepiece used in JH's solar spectrum observations.
Describes debate at R.A.S. over the nature of the 'willow leaves.' Different parties argue that the 'leaves' are solid, precipitate, or non-luminous gas.
Richard Hodgson claims to have invented the diagonal solar eyepiece despite JH's description of it in Cape Results.
Compares W. L. Newman's and CP's calculations of optical coefficients to those in JH's work. Sends JH formulae and tables for calculating telescopic lens thickness and shape in relation to the dimensions of the telescope. Wishes JH luck on Iliad.
Visits Angelo Secchi at Rome observatory, where they are comparing information in Cape Results to their observations.
Asks JH's opinion on CP's eclipse observations plans, especially on which equipment to use. Intends to use a 'diagonal solar eyepiece' during the eclipse. Plans to observe carefully and to sketch solar flares.
Sends observations of eclipse; asks JH to check accuracy. Details observations with diagonal solar eyepiece. Describes solar corona and lists bright stars visible during totality.
Observes and measures sunspots. Takes spectrum of solar photosphere; detects sodium and magnesium absorption lines. Pleased with Alexander Herschel's work on the solar spectrum; wishes he would begin work on stellar spectra.
Thanks JH for solar observations. Discusses 'willow leaves' observations made at Greenwich Observatory after following JH's suggestions for solar eyepiece.
Thanks JH for reading R.A.S. records. G. P. Bond will not receive R.A.S. medal. The Beaufoy Clock is recovered.
Richard Hodgson pursues claim to invention of the diagonal solar eyepiece while claiming that JH disclaimed the invention.
Compares JH's equation for lens curvature with that of C. F. Gauss.
Tests several possible rules for curving lenses including W. L. Newman's and [Thomas] Cooke's. Tries to put W. L. Newman's rules for lens thickness-to-curvature ratios in a simpler equation.
Asks if JH still considering editing William Herschel's R.S.P.T. publications. Suggests that Alexander Herschel edit the work. Speculates that William Herschel observed the 'willow leaves.' JH's star catalogue will be printed by the R.A.S.
Looking forward to visit to Collingwood.
Gratitude for JH's gift of Caroline Herschel's autograph manuscripts to R.A.S.