In Search of Vulcan

Moreux Abbé Th. , “Mercury and Intra-Mercurial Planets”, Scientific American supplement no. 1680, 14 March 1908, 163.

Comptes rendus des séances de l'Académie des Sciences, xxix (1849), 1–3.

Ibid., xlix (1859), 379–83.

Ibid., 383–5.

Text of letter printed in ibid., 1 (1860), 40–45.

Leverrier's account of his trip to Orgères in ibid., 45–46. Abbé Moigno in the magazine Le cosmos gave a detailed account of Lescarbault's self-built observatory and Leverrier's stiff cross-examination of his March 1859 sighting. See Monthly notices of the Royal Astronomical Society (London), xx (1859–60), 98–101. Lescarbault had constructed his own pendulum with an ivory ball and a piece of string in order to count seconds, as his watch had no second hand. Short of paper, his notes were made by a piece of charcoal on an erasable board. His equipment was later made the subject of ridicule by Camille Flammarion.

The Spectator article was reprinted in the New York Times, 10 February 1860, 3.

Monthly notices, xx (1859–60), 100–1.

The Times (London), 10 January 1860, 11. Scott was one of several British observers to neglect the exact date and time of transit.

Letter from Wolf R. to Leverrier , Comptes rendus, 1 (1860), 482.

Monthly notices, xx (1859–60), 195.

Ibid., 344.

Letter of Emm. Liais of 8 March 1860, Astronomische Nachrichten, lii (1860) (no. 1248), 369. Liais had spent the better part of 1859 in solar observation with superior equipment to Lescarbault's. However, Olin J. Eggen feels that the tone of Liais's letter was too bitterly hostile to Leverrier to be fully reliable, and it could, in part, be discounted. Liais was a known rival of Leverrier. See Eggen , “Vulcan”, Astronomical Society of the Pacific leaflet no. 287, March 1953, 294.

Flammarion Camille , Mémoires biographiques et philosophiques d'un astronome (Paris 1911), 188–90.

Astronomical register, iv (1866), 129–31. Vulcan here is listed as the first planet in a descriptive account of the planets. The Lummis observation was marred by the observer's departure from his telescope to pursue official duties. When he returned, the object was no longer to be seen.

Eggen , “Vulcan”, 294.

Letter of Coumbary , Comptes rendus, lx (1865, ii), 1113. For a general list of observations see ibid., lxxxiii (1876), 621–3.

Letter of Gould to Yvon Villarceau of 7 September 1869, ibid., lxix (1869), 813–14. Gould claimed that he would have seen anything brighter than 6th magnitude. 400 photographs taken in the United States supported him. Consequently, he claimed that the hypothesis of an intramercurial planet could be dispensed with. Nonetheless, Villarceau did not consider the case closed. Nothing was seen by Simon Newcomb during the same eclipse. However, according to the Sioux City Daily Times, four local residents independently discovered an unknown object during the eclipse both with and without optical instruments; Astronomical register, vii (1869), 227.

Denning's correspondence to the Astronomical register, vii (1869), 89, 113; viii (1870), 77–78, 108–9; ix (1871), 64.

Editorial account in the New York Times, 27 May 1873, 4.

Ibid. A reader, “H.E.P.”, referred to this editorial in his 6 July letter to the paper. He claimed to have seen a well-defined black spot on the Sun on 8 May 1860 while taking the time with a Dent's dipleidoscope with telescope attached. The limited range of his instrument prevented him from observing it for long. The Times editorial spurred him to look again, and he found the spot with the same equipment on 26 and 27 June and immediately recognized it. He said he did not remember the precise date of the French discovery, so he could not decide whether the honour of the first discovery of Vulcan should belong to a Frenchman or to an American citizen.

Letters from Wolf to Leverrier of 26 August and 6 September 1876, Comptes rendus, lxxxiii (1876), 510, 561; Scientific American, 21 October 1876, 257.

Comptes rendus, lxxxiii (1876), 621–4, 647–8. To these was added a sixth in late October when Hind wrote from Britain that there had also been an observation on 9 October 1819 by Stark which conformed with the others. Letter from Hind to Leverrier , ibid., 809.

New York Times, 7 October 1876, 1. Watson James relayed Leverrier's message to American astronomers through the Associated Press. The Times had editorially announced on 26 September on the strength of Leverrier's prediction that Vulcan definitely existed.

Comptes rendus, lxxxiii (1876), 719.

Scientific American, 11 November 1876, 304; 16 December 1876, 390.

Janssen J. , “Note sur les passages des corps hypothétiques intra-mercuriels sur le soleil”, Comptes rendus, lxxxiii (1876), 650–1.

Correspondence published in issues of 21 October, 11, 18, 25 November, 16 December 1876.

Comptes rendus, lxxxiv (1877), 367.

Professor Davidson of the U.S. Coast Survey believed he would have seen anything with a diameter larger than five seconds of arc. He saw nothing in the three-day period from Summit, California; New York Times, 27 March 1877, 4. All other accounts were equally negative.

Nature, 15 August 1878, 426; New York Times, 30 July 1878, 5.

New York Times, 8 August 1878, 5. Watson's original co-ordinates were 8^h 26’ 54” right ascension, +18° 16’ declination.

Nature, 22 August 1878, 433.

Ibid., 19 September 1878, 539.

New York Times, 16 August 1878, 5.

Ibid.

Nature, 1 and 8 August 1878, 353, 380, 385.

Scientific American, 31 August 1878, 128.

Mouchez E. , “Nouvelle observation probable de la planète Vulcan par M. le professeur Watson”, Comptes rendus, lxxxvii (1878), 229.

Comptes rendus, lxxxvii (1878), 514.

Nature, 5 September 1878, 495.

Ibid. The position of this second object was 8^h 8’ 38”, + 18° 3′.

Ibid., 10 October 1878, 616.

Comptes rendus, lxxxvii (1878), 427.

Nature, 26 September 1878, 569.

von Oppolzer Th. , “Sur l'existence de la planète intra-mercurielle indiquée par Le Verrier”, Comptes rendus, lxxxviii (1879), 26.

Astronomische Nachrichten, xciv (1878) (nos. 2253–4), 321. Proctor Richard A. who had expressed his acceptance of the eclipse sightings in the London Times of 14 August 1878, now repudiated his own article and wrote an essay indicating his doubts on the reliability of the observations of Swift and Watson as well as that of Lescarbault. His criticism was more mild than that of Peters. The essay was finally published in 1883. Proctor , Rough ways made smooth (London, 1883), 32–57.

Watson letter of 15 May 1879, Astronomische Nachrichten, xcv (1879) (no. 2263), 103–4. The feud with Peters continued until Watson's death in 1880. At his death Watson was constructing a special observatory at the University of Wisconsin to look for Vulcan.

Ibid. (no. 2277), 319–24.

The observatory, ii (1879), 389, 424.

Nature, 22 January 1880, 287.

Ibid., 14 June 1883, 145. Swift, who had continued to voice his faith in Vulcan, was now grasping at straws. In an 1883 article prior to the return of the Caroline Island expedition, he stated that it was possible that the intra-mercurial matter was too small to be seen on the solar surface in transit. But perhaps the current expedition would locate the missing planet. “Intra-Mercurial Planets—One, Many, or None?”, Sidereal messenger, ii (June 1883), 122–3. Once the expedition returned, Swift tried to fashion a planet out of a rather dubious sighting by E. L. Trouvelot of the Meudon Observatory in France. Trouvelot had seen a very red star about three degrees northwest of the Sun in his finder, but while trying to zero in with the large telescope, “time” was called and he had to switch to other pre-assigned duties. Swift suggested, after talking with the friendly but non-committal Trouvelot, that an eclipse must cause, in some way, planetary matter to turn red while ordinary stars remain white. When Swift found no red stars in that area after a subsequent search, he announced that Trouvelot's red star must have been a planet; New York Times, 29 July, 1883, 2; 4 August 1883, 3.

Letters of Backhouse of 20 October 1884 and 19 May 1885, Astronomical register, xxii (1884), 273; xxiii (1885), 144.

Clerke Agnes M. , citing Peters's Astronomische Nachrichten article, declared the probability of Vulcan's existence to be very low; Clerke , A popular history of astronomy during the nineteenth century (London, 1886), 294.

Busco Pierre , L'évolution de l'astronomie au xix^e siècle (Paris, 1912), 35–36.

Newcomb Simon , “The Abnormal Behaviour of the Perihelion of Mercury”, reprinted in A source book of astronomy, ed. by Shapley Harlow and Howarth Helen E. (New York, 1929), 338–44.

Newcomb , The elements of the four inner planets and the fundamental constants of astronomy, Supplement to the American ephemeris and nautical almanac for 1897 (Washington, D.C., 1895), 109–23.

A computation attributed to Newcomb and Herzer by Bird J. Malcolm , Relativity and gravitation (London, 1921), 301.

Pickering Edward C. , “Photographic Search for an Intra-Mercurial Planet”, Scientific American, 10 March 1900, 154.

Campbell W. W. , “The Closing of a Famous Astronomical Problem”, Popular science monthly, May 1909, 496.

Ibid. See also Perrine C. D. , “The Lick Observatory-Crocker Expedition to Observe the Total Solar Eclipse of 1901, May 17–18”, Astronomical Society of the Pacific publications, xiii (1901), 187–204.

Campbell W. W. and Perrine C. D. , “The Lick Observatory-Crocker Eclipse Expedition to Spain”, Astronomical Society of the Pacific publications, xviii (1906), 13–36.

Campbell , “The Closing of a Problem”, 500.

Bergmann Peter G. , The riddle of gravitation (New York, 1968), 147.