Transit of Venus expedition to Réunion (1874)
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The Dutch Transit of Venus Expeditions of 1874 and 1882 Robert van Gent, Anne Zandstra, Hans Hooijmaijers & Klaus Staubermann The visibility circumstances of the transit of Venus of 9 December 1874 Begin of the transit 1:49 UT End of the transit 6:26 UT Frederik Kaiser (1808-1872) Volkert S.M. van der Willigen (1822-1878) Transit of Venus expedition to Réunion (1874) Location: Saint Denis, Ile de la Réunion (Indian Ocean) Longitude 55° 27' 01.1" East Latitude 20° 51' 35.3" South • Jean Abraham Chrétien Oudemans (1827-1906): Chief astronomer. Head Geodetic Survey of Java. Trained by Frederik Kaiser (director of Leiden Observatory from 1837 to 1872). Director of Utrecht Observatory from 1876 to 1895. • Pieter Jan Kaiser (1838-1916): Astronomer responsible for the photographic observations. Head Department of Verification of Nautical Instruments. Son of Frederik Kaiser. • Ernst Frederik van de Sande Bakhuyzen (1848-1918): Astronomer. Younger brother of Hendrik Gerard van de Sande Bakhuyzen (director of Leiden Observatory from 1872 to 1908). Director of Leiden Observatory from 1908 to 1918. • Hendrik Theodorus Soeters (1842-1879): Assistant of J.A.C. Oudemans. Engineer Geodetic Survey of Java. • Marinus Bernardus Rost van Tonningen (1852-1927): Photographer assigned to assist P.J. Kaiser. • T.F. Blanken: First mate. Dealt with shipping matters and other odd jobs. Shipping routes of the Compagnie des Messageries Maritimes (Archives Leiden Observatory) Main Instruments carried to Réunion (1874) • Photoheliograph by Dallmeyer (Teyler's Stichting, Haarlem) • Refractor by Utzschneider & Fraunhofer (Mrs. de Beaufort-Stoop) • Merz heliometer (Hollandsche Maatschappij der Wetenschappen/Haarlem & Bataafsch Genootschap/Rotterdam) • Steinheil refractor (Leiden Observatory) • Airy double-image micrometer (Leiden Observatory) • Astronomical timekeeper by Fraunhofer & Utzschneider (Leiden Observatory) • 14 chronometers (Topographical Survey of Java: Hohwü 394, 455, 502 & 514, Schmidt 325 & 334; Teyler's Stichting: Knoblich 1700; Leiden Observatory: Kiek & Casseres 547, 549 & 556, Hohwü 568, 591 & 594, Arnold 418) • 2 universal instruments (Topographical Survey of Java: Repsold and Pistor & Martins) • 3 heliotropes (Leiden Observatory & Polytechnic Institute Delft) • 2 models of the transit of Venus by Boosman (Leiden Observatory) Refractor by Utzschneider & Fraunhofer lent by mrs. Anna Alida de Beaufort-Stoop Ø = 9.6 cm; f = 160 cm Museum Boerhaave, Leiden Chronometer by Knoblich & Krille (Altona) Teylers Museum, Haarlem Model of a Transit of Venus by Willem Boosman (Museum Boerhaave, Leiden) P.J. Kaiser’s 1862 thesis on the use of photography in astronomy Photoheliograph by John Henry Dallmeyer (London) Ø = 10.0 cm, f = 230 cm Plate size = 16.3 × 16.3 cm Mounting by H. Olland (Utrecht) Teylers Museum, Haarlem Plate measuring engine by Repsold & Söhne (Museum Boerhaave, Leiden) Sketch map of Reunion (Archives Leiden Observatory) Sketch map of Saint-Denis Archives Leiden Observatory Living quarters in Saint-Denis (Archives Utrecht Observatory) The members of the 1874 transit of Venus expedition Standing (f.l.t.r.): P.J. Kaiser, M.B. Rost van Tonningen, T.F. Blanken(?) Seated (f.l.t.r.): J.A.C. Oudemans, H.T. Soeters(?), E.F. van de Sande Bakhuyzen Observation camp in Saint-Denis (Archives Utrecht Observatory) Observation camp in Saint-Denis (Archives Utrecht Observatory) Present-day view of the observation camp (photograph Dominique Tournès) “A day with the natives” (Archives Utrecht Observatory) Telegram & transcript of the results (Archives Leiden Observatory) The visibility circumstances of the transit of Venus of 6 December 1882 Begin of the transit 13:57 UT End of the transit 20:15 UT Transit of Venus expedition to Curaçao (1882) Location: Fort Nassau, Willemstad, Curaçao (West Indies) Longitude 68° 56' 17" West Latitude 12° 07' 30" North • Paulus Hendricus Brocx (1856-1933): Chief observer. Naval officer 2nd class. Son of Lodewijk Gerard Brocx, Minister of Naval Affairs from 1868 to 1873. • Pieter Cornelis Swaan (1857-1931): Assistant. Naval officer 2nd class. • H. Lelyveld: Assistant. Second mate. Propeller steam ship 3rd class Alkmaar (Maritime Museum, Amsterdam)
