From climax to anticlimax

Part of the Science Networks. Historical Studies book series (SNHS, volume 37)


Until 1760 there had only been eight observations that related to the supposed moon of Venus, and they were scattered over more than a century. The situation changed drastically in the following year, which should undoubtedly be seen in the context of the long-awaited Venus transit of 1761, an event that focused international astronomical attention on the course of the planet.1 It is possible that transits of Venus have been observed before the invention of the telescope, for under the right circumstances a Venus transit should be visible to the naked eye. When the planet passes in front of the Sun, its apparent diameter is about 1/31 of that of the Sun. However, claims of pre-telescopic observations remain speculative.2


German Translation Optical Illusion Venus Diameter Amateur Astronomer Paris Academy 
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  1. 2.
    See the critical discussion in Goldstein 1969 of possible transit reports made by Avicenna, Averroes and other Islamic astronomers in the Middle Ages. Kepler and some of his contemporaries believed that a Mercury transit had been observed in Europe in the ninth century (van Helden 1976b and Sheehan and Westfall 2004, pp. 57–59).Google Scholar
  2. 3.
    On the correct explanation of the black drop effect, see Schaefer 2001. Something like the modern understanding of the effect was first proposed by Lalande in 1770, although his explanation was incomplete (Lalande 1773).Google Scholar
  3. 4.
    More complete lists, including details of the observations, can be found in Haase 1860–69, p. 8, Stroobant 1887a, pp. 6–9, and Schorr 1875, pp. 66–67. The first list of observations of the Venus moon appears in Lambert 1775, p. 186, and includes data from Cassini in 1672 to Montbarron in 1764.Google Scholar
  4. 5.
    Ferguson 1778, p. 18, the sixth edition, corrected and with an appendix on the results of the 1761 Venus transit observations.Google Scholar
  5. 6.
  6. 7.
    The Jesuit order was disbanded by Pope Clement XIV in 1773. On the strained relationship between Lagrange and Boscovich, see Hill 1961, pp. 81–93. Lagrange published several astronomical and meteorological observations, but apparently not on the satellite of Venus (Poggendorff 1863). Pezenas (1692–1776), his mentor, became director of the observatory in Avignon, where he specialized in solar research and in 1774 published Nouvelles théorie du Soleil.Google Scholar
  7. 8.
    Reported by Lalande in his article on the Venus moon in Encyclopédie II, p. 259. On the Limoges observations, see below. Lalande praised Lagrange as an astronomer recognized for his experience and accuracy, for which reason his observations deserved to be taken seriously.Google Scholar
  8. 9.
    Not much is known about Baudouin de Guèmadeuc (1737–1817), but see the account in Michaud 1857, p. 37, where his year of birth is given as 1734. According to George Sarton, he was a benefactor of the pioneer historian of mathematics Jean-Etienne Montucla (1725–1799). When Baudouin was calumniated and exiled, Montucla defended him (Sarton 1936, p. 527) and in 1802 he took care to include him in his Histoire des mathématiques (vol. 4, p. 16). See also the editorial note in Galiani 1818, pp. 53–54.Google Scholar
  9. 11.
    Galiani to Baudouin, 20 April 1770, in Galiani 1818, vol. 1, pp. 53–59. Most of the letters are addressed to Louise-Florence d’Épinays (1726–1783), the French writer and close acquaintant of Jean-Jacques Rousseau (1712–1778) and the circle around the Encyclopédie.Google Scholar
  10. 12.
    Eight years earlier, Chappe (1722–1769) had made an equally adventurous expedition to Siberia, where he made transit observations in Tobolsk. On his involvement in the Venus transit projects, see Woolf 1959, pp. 115–126, 157–159. His posthumous account of the Californian expedition appeared as Chappe d’Auteroche 1772 and six years later as an English translation, A Voyage to California to Observe the Transit of Venus (London: Edward & Charles Dilly, 1778).Google Scholar
  11. 13.
    According to Hell 1792, p. 20.Google Scholar
  12. 14.
    Even less is known about Montaigne than about Baudouin, except that he, an able observer of comets, was born on 6 September 1716 in Narbonne (Lalande 1803, p. 477). He is listed in Poggendorff 1863, but without a first name and with no publications. See also Lynn 1884 and Thirion 1885, pp. 45–46. On his comet of 1772, today known as 3D/Biela, see section 6.1.Google Scholar
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    Encyclopédie II, p. 258.Google Scholar
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    Baudouin 1761c which includes translations of both of the French memoirs. On Hell’s reception of Baudouin’s memoir, see Hell 1766, p. 11. Among those who possessed the German text, and probably studied it, was Immanuel Kant, cp. Kant scholars agree that he only acquired books that he actually read.
  15. 17.
    Only five monthly issues, all of 1761, appeared of the Mathematical Magazine. On Bevis (1695–1771), see Wallis 1982. In a booklet of 1883, the amateur astronomer Leeson Prince reproduced Bevis’ translation of the Baudouin-Montaigne work. See Prince 1883 and also Lynn 1887a.Google Scholar
  16. 18.
    Hell 1765, p. 6. Wargentin (1717–1783) was a prominent Swedish astronomer, see section 4.2. Gotthilf Christian Reccard (1735–1798) was at the time he translated Baudouin’s work a school inspector in Berlin. After having moved to Königsberg in 1765, he was appointed professor of theology and thus became a colleague of Kant. Better known as an astronomer than as a theologian, he built his own observatory and published several works in astronomy, including a treatise on the solar eclipse observed on 1 April 1764.Google Scholar
  17. 19.
    Baudouin 1761c, p. 3 and p. 31. According to Moore 1956, p. 128, Baudouin also reported on the measurements in Dictionnaire de physique of 1789, but we have not been able to locate this source (it may refer to Lalande 1781). Ley 1964, p. 218, states that it was Montaigne who read the memoir to the Paris Academy in 1761, and that he “had repeatedly expressed skepticism toward the existence of a satellite of Venus.” The first claim is wrong and the second lacks solid documentation.Google Scholar
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    Lalande, who observed the 1761 transit from the Palais du Luxembourg, referred to the observations of Baudouin and Messier in Lalande 1763b (p. 84).Google Scholar
  19. 21.
    Baudouin 1768a. In Baudouin 1768b he reported observations of two of Jupiter’s moons, made in November 1761. The two communications were abstracted in Bernoulli 1771, pp. 156–158. Baudouin’s articles and addresses read to the Paris Academy indicate that at the time he was considered with some respect by the French astronomical community.Google Scholar
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    Baudouin 1761c, p. 24.Google Scholar
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    Montucla 1802, p. 16. The author must have known, for most of the volume was written by Lalande, who also served as an editor. (Montucla died in 1799, before his work was completed.)Google Scholar
  22. 24.
    Newton 1999 (based on the third edition of 1726), pp. 812–813. See also I. Bernard Cohen’s clear exposition on pp. 218–228 and the recalculation in Garisto 1991. Newton found that the mass of the Sun was 1,067 times that of Jupiter and 3,021 times that of Saturn; the modern values are 1,047 and 3,498, respectively. For the Earth, Newton got 169,282, while the present value is 332,946.Google Scholar
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    Lemonnier 1746, p. 558. Contrary to other observers, William Herschel found that Venus was a little larger than the Earth (Herschel 1912, vol. 1, p. 450).Google Scholar
  24. 26.
    Baudouin 1761c, p. 48.Google Scholar
  25. 27.
    Ibid., pp. 47–48. See also Lynn 1887a. It is hard to understand how Baudouin could have made this elementary mistake, especially if he was assisted by Lalande.Google Scholar
  26. 28.
    Baudouin 1761a, pp. 23–25.Google Scholar
  27. 29.
    Baudouin 1761b, pp. 15–16, followed by a certification by Grandjean de Fouchy (1707–1788). Most of the passage appeared in English translation in Hutton 1795, vol. 2, p. 649. Neither of the two postscripts were included in the German translation. According to Hell 1792, p. 116, Lacaille was opposed to Baudouin’s memoir and its claim of a Venus moon. He was, so Hell suggested, fooled or forced to support the publication of the work.Google Scholar
  28. 30.
    Encyclopédie II, p. 260. Lalande’s argument is not very clear.Google Scholar
  29. 31.
    Paulian 1781, pp. 336–337. The articles in the dictionary appeared anonymously, but it is most likely that the author of the entry on Venus’ moon was Lalande.Google Scholar
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    Lalande 1795, p. 322. On the arguments of Hell and Boscovich, see section 4.2.Google Scholar
  31. 33.
    Lalande 1803, p. 477.Google Scholar
  32. 34.
    Messier 1784, which includes excerpts of letters from Montaigne to Messier (1730–1817). For Montaigne’s letters to Messier, dating from 1770, 1772 and 1780, see Bigourdan 1904.Google Scholar
  33. 35.
    Olbers 1804, p. 176. See also Lynn 1887b.Google Scholar
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    Letters of 14 November and 28 December 1775, reproduced in Lambert 1776, pp. 186–188. See also Stroobant 1887a, pp. 41–42.Google Scholar
  35. 37.
    Mentioned in Encyclopédie II, p. 259. The source is the London Chronicle or Universal Evening Post 9, no. 699 (16–18 June 1761), here quoted from Haase 1863–69, p. 11. See also Stroobant 1887a, p. 43. The observation in St. Neot was reported to the French-speaking world in an article of August the same year in the Journal Étranger.Google Scholar
  36. 38.
    Lacaille 1763, p. 78.Google Scholar
  37. 39.
    Cassini de Thury 1763, p. 412. J. L. Liesganig (1719–1799) served as astronomer and professor of mathematics at the Collegio Viennensi until 1773, when the Jesuit order was dissolved. Present at the observations in Vienna was also Maximilian Hell.Google Scholar
  38. 40.
    Pingré 1763, p. 376. On Pingré’s (1711–1796) adventurous voyage to Rodrigues and his transit observations, see Woolf 1959, pp. 98–115.Google Scholar
  39. 41.
    Ferner 1763, p. 225, who made his observations in company with Jean Paul Grandjean de Fouchy, secretary of the Académie des Sciences from 1743 to 1776. The letter is dated 20 June 1761.Google Scholar
  40. 42.
    Dunn 1763, p. 189. Samuel Dunn (1723–1794) wrote several tracts on astronomy, nautical science and instruments. In 1769 he was invited by Nevil Maskelyne (1732–1811), the Astronomer Royal, to observe the transit of Venus, and he was one of the first to observe evidence for an atmosphere on the planet (Meadows 1966).Google Scholar
  41. 43.
    Chapple 1761a. In Chapple 1761b, he revised his data for the transit, without mentioning the satellite of Venus.Google Scholar
  42. 44.
    Bliss 1762, figure on p. 244.Google Scholar
  43. 45.
    Winthrop 1764, p. 283. Woolf 1959, pp. 93–94. On John Winthrop (1715–1779) as an astronomer, see Brasch 1916.Google Scholar
  44. 46.
    Quoted in Wolf 1857, p. 276. Over a period of forty years, Staudacher (1731–1792) made observations of sunspots. These and other of his astronomical data were later published by another Nuremberg astronomer, Johann Woeckel (1807–1849). See Woeckel 1846.Google Scholar
  45. 47.
    Wales and Dymond 1770. On the expedition to Canada, see Metz 2006. On Wales’ astronomical and nautical voyages, see Orchiston and Howse 1998.Google Scholar
  46. 48.
    Reported in Hell 1765, p. 26, here quoted from the German translation in Haase 1863–69, pp. 252–253. A briefer account of Montbarron’s observations was brought in Encyclopédie II, p. 259. Montbarron is not mentioned in Poggendorff 1863, Hockey 2007 or other standard sources.Google Scholar
  47. 49.
    Messier 1767, p. 57.Google Scholar
  48. 51.
    Hoyt and Schatten 1995. The 11-year sunspot cycle was discovered about 1840 by Heinrich Schwabe (1789–1875), a pharmacist and amateur astronomer in Dessau, Germany, while looking for evidence of an intramercurial planet.Google Scholar
  49. 52.
    Christian Horrebow was only appointed full professor in 1764, at the death of his father Peder Nielsen Horrebow (1679–1764) who held the chair 1713–64 (and had earlier worked as the assistant of Ole Rømer). However, since 1753 the younger Horrebow had served as director of the observatory and de facto as professor of astronomy. On Christian Horrebow, see Moesgaard 1972, who fails to mention his work on Venus and its satellite. On the Danish transit observations of 1761 and 1769, see also Pedersen 1992, pp. 102–104, and Nielsen 1957a (in Danish).Google Scholar
  50. 53.
    Horrebow 1761a; Horrebow 1765c; Lalande 1763a.Google Scholar
  51. 54.
    Horrebow 1761b, p. 20.Google Scholar
  52. 55.
    Horrebow 1761a, unpaginated introduction.Google Scholar
  53. 56.
    The observations of 1761 remained unknown until 1882, when the Copenhagen astronomer Hans C. F. C. Schellerup (1827–1887) reproduced them in their original Latin from the old observations ledger. See Schjellerup 1882, who however seems to have been unaware of Horrebow’s two dissertations of 1761. The observations of Roedkiær and Horrebow are not well known in the history of science. Pedersen 1992, p. 80, briefly notes that Roedkiær published “a report of an observation of the (alleged) satellite of Venus,” but that is all.Google Scholar
  54. 57.
    Observation report of 28 june 1761, in Schellerup 1882, p. 165. This and the subsequent translations from Latin have kindly been made by Henk Bos.Google Scholar
  55. 58.
    Artzt 1813, pp. 453–454.Google Scholar
  56. 59.
    Schjellerup 1882, pp. 166–167.Google Scholar
  57. 60.
    Roedkiær 1765. See also Horrebow 1765c.Google Scholar
  58. 61.
    Horrebow 1765c, p. 402.Google Scholar
  59. 62.
    Ibid., p. 403.Google Scholar
  60. 63.
    A German translation of Hell’s Latin version of the French account in the Gazette Litéraire (based on the original Danish) appears in Haase 1863–69, pp. 251–252.Google Scholar
  61. 64.
    Schjellerup 1882, pp. 167–168. The “Islaean telescope” refers to a kind of refractor named after the French physicist and astronomer Joseph Nicolas Delisle (1688–1768). C. H. = Christian Horrebow; O. B. = Ole Bützov; J. = Ejolvor Johnsen. In company with Peder Horrebow junior (1728–1812), Bützov (1742–1784) went the following year to the northern parts of Norway to observe the Venus transit. During 1773–78 he was in charge of the small observatory at Vardø.Google Scholar
  62. 65.
    Hell 1792, p. 118. Hell was on his way to Norway to observe the Venus transit of 1769 (see section 4.2).Google Scholar
  63. 66.
    Bugge 1783, p. 219. On the works of Hell and Lambert, see sections 4.2 and 4.3.Google Scholar
  64. 67.
    Lambert 1775, p. 181.Google Scholar
  65. 68.
    On Bonnet (1720–1793) and the principle of plenitude, see the classic account in Lovejoy 1964, first published in 1936.Google Scholar
  66. 69.
    Bonnet 1764, pp. 7–8. In a later edition, Bonnet added in a lengthy footnote a sketch of the history of the satellite of Venus from Cassini to Lambert, leaving the erroneous impression that Cassini, as well as Short and Lambert, firmly believed in the existence of the satellite (see the excerpt in Thornton 1804, p. 328).Google Scholar
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    Bonnet 1766, pp. 7–8. Reproduced in Nieto 1972, plate IV. Readers of the German translation would believe that the law of planetary distances was due to Bonnet, as Titius (1729–1796) did not disclose the authorship of the inserted section. For details on the origin and historical development of the Titius-Bode law, see Jaki 1972a, Jaki 1972b and Nieto 1972.Google Scholar
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    Same title and publisher as Bonnet 1766, p. 7. Reproduced in Nieto 1972, plate V.Google Scholar
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    For valuable background to Frederick II (1712–1786) as a philosopher-king and his reestablishment of the Berlin Academy in the 1740s, see Terrall 1990. See also Taton 1984, reprinted in Taton 2000, pp. 261–272.Google Scholar
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    Frederic II, 1805, p. 19 and also in d’Alembert 1822, pp. 256–257. Part of the letter has been quoted in the earlier literature, e.g. in Schorr 1875 (p. 73), Wolf 1877 (p. 679) and Littrow 1886 (p. 101), but always without date and reference. Ley 1964, p. 219, states that King Frederick read Lambert’s essay, a claim for which there is no documentation.Google Scholar
  71. 75.
    d’Alembert 1822, p. 79.Google Scholar
  72. 76.
    Oeuvres Complète de Voltaire, Mélanges VI. The title of Voltaire’s work was Des singularités de la nature par un académicien de Londres, de Bologne, de Pétersbourg, de Berlin etc. See Roe 1985. On Voltaire and the sciences, see Perkins 1965, which mostly deals with his critical attitude to ideas of natural history.Google Scholar
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    Quoted in Nisbet 1970, p. 141, which offers a detailed exposition of Herder’s view on science and suggests that his ideas of astronomy were inspired by Kant. Anfangsgründe der Sternkunde was based on notes made by Liborius Bergmann, a student in Herder’s class in the Cathedral school in Riga in 1765. Given that G. C. Reccard, the translator of Baudouin’s memoirs on the Venus moon (cp. section 3.1), served as professor in Königsberg at the same time as Kant and Herder, one can imagine that the topic was discussed and widely known.Google Scholar
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    Herder 1787, p. 35. See also Crowe 1999, p. 151. One of the minor planets (1989 UH7) is named after Herder.Google Scholar
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    Palti 1999, p. 326, who argues the connection between Herder’s philosophy and the cosmological views of Kant and Lambert.Google Scholar
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    Kant 1981, pp. 131–132.Google Scholar
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    Martin 1781, p. 263. The Young Gentleman and Lady’s Philosophy first appeared in the General Magazine of Arts and Sciences, a journal edited and largely written by Martin (1704–1782) in the years 1755–65.Google Scholar
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    Ibid., p. 264.Google Scholar
  79. 83.
    Martinet 1779, where the Venus moon is discussed on pp. 212–214 and on p. 1 in the appendix. On Martinet (1729–1795) as an exponent of enlightenment physico-theology, see van der Wall 2004. In 1769 he was elected a member of the Dutch Society of Sciences (Hollandsche Maatschappij van Wetenschappen), founded in Haarlem in 1752.Google Scholar
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    Review in Algemeene Vaderlandsche Letter-Oefeningen 1792, pp. 97–101.Google Scholar
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    Helmuth 1794 (second edition), p. 196. The first edition was published in 1791. Helmuth (1732–1813) was superintendent and minister in Calvörde in the dukedom of Braunschweig-Lüneburg. On Lambert’s prediction, see section 4.3.Google Scholar
  82. 86.
    Ibid., p. 287.Google Scholar

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