Encloses a letter from Boston, which may host an observatory. Has sent Boston information.
Encloses a letter from Boston, which may host an observatory. Has sent Boston information.
Encloses a letter from [John] Lefroy about an 'outbreak of [solar] spots' observed at a certain time. Speaks of purchasing instruments and of writing to the secretary of the Amer[ican Philosophical?] Society.
Rejoices at welcome JH received on returning to England from the Cape. Excellent resources at his disposal at Pulkowa. Mentions coin, commemorating opening of the observatory, sent to JH by means of [H. C.] Schumacher. Refers to [Otto] Struve's work on double stars. Lauds capacity of large refractor at Pulkowa Observatory.
Formally reports on paper by Baden Powell on theory of dark bands found in solar spectrum. G. B. Airy agrees with JH's report.
Will be unable to attend Council meeting, but comments on issue to be discussed of whether R.S.L. should do anything respecting observatory at Hammerfest (North Cape).
Has a problem with the explanation of interference bands produced by mica being placed between the eye and prism-produced dispersion; the explanation is Baden Powell's.
Writes to supply GA with an address for a reply to JH's 1840-5-16.
Responds to JH [see JH's 1840-5-16 or later] indicating to what address GA had sent his reply [see GA's 1840-5-17].
Thanks GA for the time and trouble GA took in writing about interference bands [see GA's 1840-5-17]; JH's wife, Margaret, is making many visits to the dentist.
A note agreeing with GA about prism interference [see GA's 1840-5-20].
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.
Regarding Prof. Baden Powell's paper on dark bands. Is making catalogues of the moveables of the observatory.
Concerning prism refraction.
Would FB deputize for him at the council meeting on Friday as he is unable to attend. Letter from F. W. Bessel regarding 61 Cygni. Has written to G. B. Airy regarding Thomas Maclear's paper.
Just moved [to Collingwood]. Will send information about ED's late son, Thomas Drummond. Recalls Drummond's fame and triangulation work on Irish Survey. Describes invention and first demonstration of Drummond Light.
How to reduce barometer observations and project them in curves. R.S.L. will provide table by H. C. Schumacher for this purpose. How to obtain 'law of decimal oscillations' for each station. WB's name will be affixed to results. JH needs receipt for observations, which belong to South African Literary and Philosophical Society.
Thanks for excellent pictures WT sent. JH wishes JH had time for further experiments, especially on the 'thermic spectrum.' Praises [Robert] Hunt's results. Recommends experiment to WT.
No summary available.
No summary available.
No summary available.