Experiments with lens curvature and prisms. Wants to discover set rules for lens thickness-to-curvature ratio.
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Experiments with lens curvature and prisms. Wants to discover set rules for lens thickness-to-curvature ratio.
JH to visit CP's house. CP suggests they both visit J. P. Gassiot, where they might also meet with Michael Faraday. Asks JH if there are experiments he would like to see during visit. Reports observing Fraunhofer lines through a prism.
Looking forward to visit to Collingwood.
Congratulates JH and Margaret Herschel on birth of a daughter [Francisca?]. Asks JH's opinion of the ideas of 'lines of force' and 'lateral shakes.' Conducts a force experiment with J. P. Gassiot.
Receives object glass from Munich for double star observations.
Reports on progress of the three Herschel sons at Clapham. Asks JH's advice on his plan to construct a telescope. Looks forward to visit from JH.
Visits Angelo Secchi at Rome observatory, where they are comparing information in Cape Results to their observations.
Writes to JH to propose hiring JH's son Alexander for a year to work in CP's laboratory and make observations in CP's observatory.
Searches for asteroids. Measures double stars and variables; Alexander Herschel assists. Asks JH's opinion of parallax measuring methods. R.S.L. funds offered to M. J. Johnson's family in his memory.
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.
Has broken up school a few days early to avoid danger. Hopes CD’s son is nearly recovered.
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.