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.
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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.
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.
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.
Warren de La Rue observes 'willow leaves' [mottling on solar surface]. Diagonal solar eyepiece works with great success. Praises de La Rue's work as having astounding accuracy.
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.
Thanks JH for solar observations. Discusses 'willow leaves' observations made at Greenwich Observatory after following JH's suggestions for solar eyepiece.
Gratitude for JH's gift of Caroline Herschel's autograph manuscripts to R.A.S.
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.
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 claims to have invented the diagonal solar eyepiece despite JH's description of it in Cape Results.
Richard Hodgson pursues claim to invention of the diagonal solar eyepiece while claiming that JH disclaimed the invention.
Forwards letter concerning 'solar bright particles' by W. R. Dawes. Inquires if diagonal solar eyepiece used in JH's solar spectrum observations.
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.
Compares JH's equation for lens curvature with that of C. F. Gauss.
Praises JH's Iliad. Asks R.S.L. for funds to cover expenses incurred by spherical observations. Details information to be included in optical tables.
Requests JH's reflections on the deceased Wilhelm Struve. Discusses making of telescope object glass. Continues work on the optical tables.
R.S.L. approves of CP's optical work, believing it will be helpful at observatories abroad. CP comments on Alexander Herschel's prism experiments.
Asks if JH anticipated the results of W. L. Newman's work on lens curvature.
Informs JH, Charles Babbage, and James South that they are the surviving original members of the R.A S. Requests JH write an account of the R.A.S.'s founding. Discusses the evidence of the 'personal will' of God in creation.