MASKELYNE, Nevil (1732-1811). Astronomer royal.
Autograph Letter (third person) to Sir Joseph Banks, 2 pages 4to (roughly torn at the left hand side, not affecting the text), 58 Dean Street, 1 May 1782 ('Wednesday Afternoon, 2 o'clock').
A remarkable letter from the Astronomer Royal to the President of the Royal Society discussing errors in the calculation of the magnitude of the stars, conveying [William] Herschel's view that the fault had largely been Halley's.
'... [Maskelyne] has just received Mr. Herschell's answer in 4 quarto sheets, who is very thankful to the Committee for their attention to his paper, submitting to whatever alterations they think proper, & sending the alterations in the last sheet which he himself thinks might be made to it. Some of things objected to he justifies, others he explains or corrects; particularly he obviates the principal difficulty by defining the magnitudes of the stars to signify not that commonly received but what it should be supposing the light of a star of the 2d. magnitude to be 4 times less, the 3d. nine less & so on than that of one of the first magnitude. It seems Dr Halley first made the mistake, & not Mr Herschell ...'Maskelyne also suggests that Mr Mitchill's experiments 'can't be true'; probably referring to John Michell (1724-1793).
Not in The Banks Letters, A Calendar of the manuscript correspondence of Sir Joseph Banks preserved in the British Museum ... and other collections in Great Britain ed. Warren R. Dawson, British Museum, London, 1958, where no letters to Maskelyne are to be found prior to 1791.
With an engraved portrait of Maskelyne by Scriven after Vanderburgh.
Link to full transcript.
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