An Early Astronomical Manuscript of Jeremiah Horrocks

Horrocks Jeremiah (ed. by Wallis John ), Jeremiae Horroccii, Liverpoliensis Angli, ex palatinatu Lancastriae, Opera posthuma … (London, 1673): Containing Astronomia kepleriana defensa et promota; excerpts of Horrocks's letters to Crabtree; catalogues of Horrocks's and of Crabtree's astronomical observations; lunar theory; and works by Flamsteed.

Chapman Allan , “Jeremiah Horrocks, the transit of Venus, and the ‘new astronomy’ in early seventeenth-century England”, Quarterly journal of the Royal Astronomical Society , xxxi (1990), 333–57; Wilson Curtis , “Predictive astronomy in the century after Kepler”, chap. 10 in Planetary astronomy from the Renaissance to the rise of astrophysics, Part A: Tycho Brahe to Newton (vol. 2A of The general history of astronomy, ed. by Taton René Wilson Curtis (Cambridge, 1989)), 161–206, pp. 166–71; Wilson Curtis , “On the origin of Horrocks's lunar theory”, Journal for the history of astronomy , xviii (1987), 77–94; and Bailey J. E. , “Jeremiah Horrox”, Observatory , vi (1883), 318–28.

Rigaud P. S. Rigaud S. J. (eds), Correspondence of scientific men, ii (Oxford, 1841), letter cccxix, pp. 530–2 (John Wallis to John Collins, 13 February 1671/2): “I am sorry for the loss of Mr Horrox's papers … by the fre.” See also ref. 7.

Plummer H. C. , “Jeremiah Horrocks and his ‘Opera posthuma’”, Notes and records of the Royal Society of London , iii (1940–41), 39–52, p. 48; and Wallis John , “Epistola nuncupatoria” [Dedicatory letter], in Opera posthuma (ref. 1, unnumbered 7th, 10th, 11th pages): He had “heard” that soldiers burned some of the papers left by Horrocks.

Wallis John , “Epistola nuncupatoria” [Dedicatory letter] and “De excerptis ex Horroccii epistolis praefatio” [Preface: About the excerpts from Horrocks's letters], in Opera posthuma (ref. 1); describing how Wallis as editor made Latin collations and condensed excerpts. See also opera cit. (refs 3 and 7).

Birch Thomas , History of the Royal Society of London…, i (London, 1756), 470–1, Wallis's letter to the Royal Society dated 21 September 1664, reporting completion of “the task imposed upon him concerning Mr. Horrox's astronomical papers, by … digesting all the several pieces into one body … in order to the printing thereof”.

Wallis , op. cit. (ref. 3). Wallis's letter of 13 February 1671/2 (Rigaud, op. cit. (ref. 3), letter cccxix, 530–2) remarking on the fre loss, was part of an exchange with Collins; only Wallis's side survives. Wallis answered a question of Collins thus: “The papers that I had of Horrox and Crabtree … I returned all to Mr Oldenburg” and “What afterwards became of them I can give no account” (ibid., letter cccxviii, 528). Collins's reply gave, by inference, information about fre losses, prompting Wallis's expression of regret. Originals corresponding to some parts of Astronomia kepleriana defensa et promota survive and are listed in ref. 8.

Chapman Allan , “Jeremiah Horrocks, William Crabtree, and the Lancashire observations of the transit of Venus of 1639”, in Kurtz D. W. (ed.), Transits of Venus: New views of the solar system and Galaxy (Proceedings of IAU colloquium no.196, 2004), 3–26.

Oxford , Bodleian Library MS. Eng. e. 3388 (a sewn booklet of 38 leaves, about 14.5 cm × 9 cm), classified among “Notebooks on astronomy, mainly of Christopher Towneley, 17th–18th cent.”

Forbes E. G. Murdin L. Willmoth F. (eds), Correspondence of John Flamsteed , ii (Bristol, 1997), letter 622, pp. 418–21, 10 May 1690, showing that Christopher Towneley and Jonas Moore acquired some papers of Horrocks; Birch , History of the Royal Society , i (ref. 6), 386, a report of 17 February 1663/4 that “Mr Townley … had a considerable number of Mr Horrox's papers”.

Horrocks Jeremiah , Observationes coelestes habitae Toxtethae… , in Opera posthuma (ref. 1), 341, for an eclipse observation of August 1635, noting that the Liverpool clock sounded.

Kepler's geographical data, in Tabulae Rudolphinae (Ulm, 1627), and Lansberg's, in Tabulae motuum coelestium perpetuae (Middelburg, 1632), frequently disagree. For the difference between Uraniburg (Hven) and Goesa (Zeeland) Kepler gave 33 minutes, Lansberg 45 minutes. Disagreements elsewhere were often by lesser margins.

Horrocks , Opera posthuma (ref. 1), 58–60; Jeremiah Horrocks, manuscripts in Royal Greenwich Observatory papers at Cambridge University Library (RGO/1/68 and microform 36/1/22): Astronomicall Exercises at section 68 A, from f. 34; and Philosophicall Exercises, Section 68 B.

The 1636 June 30 observation is given (i) in Horrocks's letter to William Crabtree of 25 July 1636 (in Horrocks, Opera posthuma (ref. 1), 248); (ii) ibid., 342; and (iii) ibid., 366.

Stars Lanx borea and Lanx austrina are also known respectively as the North Scale (or β Librae or Zubeneschamali), and the South Scale (or a₂ Librae or Zubenelgenubi).

The passage translated in the main text transcribes as follows (from op. cit. (ref. 9), leaf 38v). Square-bracketed names replace astronomical symbols in the original: “1637 Nov. 25 h 7 20′ a [Mercury] dist. ab austrina lance 12/13 57/5 et a borea lance 10 40/46′ Keplerus habet in [Scorpio] 22 23 1/2 Lat 2 5′ b. ergo dist. ab austrina lance 10 57′ 1/3 a borea 10 44′ 1/3 Lanx borea fuit supra [Mercury] ergo ob differentiam refractioñ distantia vera fuit 10 45 1/2 /52.”

The passage from Opera posthuma (ref. 1), 357, cited in the main text, reads: “1637 Nov 25. Hora 7 1/4. Mercurius altus gr. 5, distabat a lance austrina gr.13, 5′, a borea gr.10, 46′. Mercurius altus gr. 7, dist. a borea lance gr.10, 46′.”

Horrocks , Astronomicall Exercises and Philosophicall Exercises (ref. 13).

Horrocks , Opera posthuma (ref. 1), 44 (Disputation I, chap. IV).

Wallis , Epistola nuncupatoria (ref. 5), third and fourth unnumbered page.

Wallis , Epistola nuncupatoria (ref. 5), seventh unnumbered page.

Horrocks , Opera posthuma (ref. 1), e.g. at p. 160 for solar parallax and pp. 39, 90 for eccentricity estimates; and Wilson, “Predictive astronomy…” (ref. 2), 167–8.

Horrocks , Astronomicall Exercises (ref. 13), f. 35.