David Gill, a Scotsman, trained as a watchmaker and worked in that profession. Timekeeping led to astronomy, and he designed, equipped, and operated a private observatory at Dun Echt near Aberdeen for James Lindsay, the Earl of Crawford. In 1877 Gill and his wife travelled to Ascencion Island to measure the solar parallax by observing Mars. After he proved the worth of the heliometer, a telescope with a divided objective, for measuring the distance to the sun, he was appointed Her Majesty's Astronomer at the Cape of Good Hope, a position he held from 1879 to 1906. He greatly improved the observatory, designing and securing new instruments of unprecedented precision. He redetermined the distance to the sun to such precision that his value was used for almanacs until 1968. He photographed the southern sky and helped initiate the international Carte du Ciel project to chart the entire sky. Gill and Jacobus C. Kapteyn, who measured Gill's photographs in the Netherlands, initiated the separation of observation from reduction. Gill also made geodetic surveys of South Africa. In fact he carried out all of the observations to measure the distances to stars in terms of the standard meter.
Presentation of Bruce medal
Pardee, George C., PASP 12, 49-55 (1900).
Government of Germany, Order Pour le Merite for Arts and Sciences, 1910.
National Academy of Sciences, James Craig Watson Medal, 1899.
Royal Astronomical Society, Gold medal, 1882, 1908, presented by H.F. Newall, MNRAS 68, 317-30 (1908).
Royal Society, Royal Medal, 1903.
Some offices held
Royal Astronomical Society, President, 1909-11.
Astronomical Society of Southern Africa
Bitterman, Jay, Lake County Astronomical Society
Forbes, George, David Gill: Man and Astronomer (John Murray, London, 1916).
Reid, John S., “Sir David Gill – Scotland’s most notable astronomer?”, The Conversation, 2014.
Reid, John, “David Gill - Magnificent and Desirable Astronomer,” presentation at the International Conference on the History of Physics held at Trinity College, Cambridge, in September 2014. arXive:1601.02519.
Stoy, R.H., Dictionary of Scientific Biography 5, 403-06.
Tenn, Joseph S., “David Gill: The Third Bruce Medalist,” Mercury 19, 3, 84 (1990).
Warner, Brian, “Sir David Gill (1843–1914)," Transactions of the Royal Society of South Africa 49, 147-53 (1994).
University of Aberdeen
Anonymous, Observatory 37, 115-17 (1914).
Dyson, F.W., Proceedings of the Royal Society A 91, xxvi-xlii (1914-15).
E[ddington], A.S., MNRAS 75, 236-47 (1915).
Kapteyn, J.C., Ap.J. 40, 161-72 (1914).
Paterson, John A., JRASC 13, 343-59 (1919).
Astronomical Society of Southern Africa (several)
David and Isobel Gill at Mars Bay, Ascension, 1877, where Gill was observing the opposition of Mars in order to measure the solar parallax. From George Forbes, David Gill: Man and Astronomer (London, 1916), facing p. 94. (sketch)
Royal Astronomical Society/Science Photo Library (several)
Stamps from Ascension Island commemorating the centenary of the Gills’ visit
University of Aberdeen Natural Philosophy Collection
Named after him
Gill’s papers are at the Royal Greenwich Observatory Archives, Cambridge University Library, the Royal Astronomical Society, the Royal Observatory, Edinburgh, and the National Archives of South Africa.
Other References: Historical
Dept of Rural Development and Land Reform, Republic of South Africa, Historical Mapping Background
Brück, H.A., “Lord Crawford’s Observatory at Dun Echt 1872-1892,” Vistas in Astronomy 35, 81-138 (1992).
Chinnici, Ileana, La Carte du Ciel: Correspondence inédite conservée dans les archives de l’Observatoire de Paris (Observatoire de Paris, Paris & Osservatorio Astronomico di Palermo, Palermo, 1999).
Clerke, Agnes M., A Popular History of Astronomy during the Nineteenth Century (Adam & Charles Black, Aberdeen, Scotland, 1885, 1887, 1893, 1902; fourth ed. reprinted by Scholarly Press, St. Clair Shores, MI, 1977).
Clerke, Agnes M., “A Southern Observatory,” The Contemporary Review 4, 380-92 (1889); reprinted in Annual Report of the Board of Regents of the Smithsonian Institution for 1891 (Smithsonian Inst., Washington, DC, 1893).
Crawford, L., “Gill’s Work on the Determination of the Solar Parallax,” Monthly Notes of the Astronomical Society of South Africa 2, 85-88 (1943).
Evans, David S., Under Capricorn: A History of Southern Hemisphere Astronomy (Adam Hilger, Bristol and Philadelphia, 1988).
Gill, David, History and Description of the Royal Observatory Cape of Good Hope ( H.M. Stationer Off., Edinburgh, 1913).
Gill, David, “Presidential Address to the British Association for the Advancement of Science,” Observatory 30, 299-306 (1907).
Gill, Isobel (Mrs. David), Six Months in Ascension: An Unscientific Account of a Scientific Expedition (John Murray, London, 1878).
Krumm, H.E., “Gill’s work on Stellar Parallax with the Heliometer,” Monthly Notes of the Astronomical Society of South Africa 2, 88-89 (1943).
Mitton, J., “David Gill and the Measurement of the Astronomical Unit,” Mercury 9, 124 (1980).
Murray, C.A., “David Gill and Celestial Photography,” in Suzanne Debarbat, ed., Mapping the Sky: Past Heritage and Future Directions: Proceedings of the 133rd Symposium of the International Astronomical Union, held in Paris, France, 1-5 June 1987. IAU Symposium no. 133 (Kluwer Academic Publishers, Dordrecht, 1988), pp.143-48.
Packer, J.E., “Astronomy in Mid-Atlantic,” Sky & Telescope 43, 74 (1972)
Rose, Colonel, “Reminiscences of Sir David Gill,” Monthly Notes of the Astronomical Society of South Africa 2, 79 (1943).
South African Astronomical Observatory, History of the South African Astronomical Observatory
Warner, Brian, Astronomers at the Royal Observatory, Cape of Good Hope: A History with Emphasis on the Nineteenth Century (Univ. of Capetown, Capetown, 1979).
Whittingdale, W., “Reminiscences of Sir David Gill,” Monthly Notes of the Astronomical Society of South Africa 2, 73-78 (1943).
Other References: Scientific
Gill, Jr., David, “Note on Stars within the Trapezium of the Nebula in Orion,” MNRAS 27, 315-16 (1867).
Gill, Jr., David, “Close Companion to Alpha Lyrae,” Astronomical Register 6, 159-60 (1868).
Lindsay, Lord & David Gill, “On Lord Lindsay’s Preparations for Observations of the Transit of Venus in 1874,” MNRAS 33, 34 (1872).
Lindsay, Lord & David Gill, “On the Determination of the Solar Parallax by Observations of Juno at Opposition,” MNRAS 34, 279-300 (1874).
Lindsay, Lord & David Gill, “Progress of Reduction of the Observations of the Transit of Venus,” MNRAS 36, 10-12 (1875).
Gill, David, “On the Proposed Expedition to Observe the Approaching Opposition of Mars,” MNRAS 37, 310-33 (1877).
Gill, David, “Mr. Gill’s Expedition to Ascension, Correspondence and Reports,” MNRAS 38, 1-11 (1877).
Lindsay, Lord & David Gill, Mauritius Expedition 1874. Determination of the Solar Parallax by Observations of the Minor Planet Juno at Opposition (Dun Echt Observatory Publications, vol. 2, 1877) [summary in MNRAS 38, 86-88 (1877)].
Gill, David, “On Observations of α Centauri Made with the Heliometer at Ascension in 1877,” MNRAS 39, 123 (1878).
Gill, David, “On the Value of the Solar Parallax Derived from Observations of Mars Made at Ascension Island during the Opposition of 1877,” MNRAS 39, 434-37 (1879).
Gill, D., “On a New Method of Determining Astronomical Refractions,” MNRAS 39, 366-68 (1879).
Gill, D., “On the Value of the Solar Parallax Derived from Observations of Mars made at Ascension Island during the Opposition of 1877,” MNRAS 39, 434-37 (1879).
Gill, David, “Observations of the Great Southern Comet 1880, I., made at the Cape of Good Hope,” MNRAS 40, 300-01 (1880).
Gill, David, “On Photographs of the Great Comet (b) 1882,” MNRAS 43, 53 (1882).
Gill, David, “Note on the Nucleus of the Great Comet (b), 1882,” MNRAS 43, 319-21 (1883).
Gill, David, “Preliminary Account of a Telegraphic Determination of the Longitude of the Royal Observatory, Cape of Good Hope,” MNRAS 43, 408-19 (1883).
Maclear, Thomas & David Gill, Catalogue of 4,810 Stars for the Epoch 1850: from Observations Made at the Royal Observatory, Cape of Good Hope: during the Years 1849 to 1852 (Eyre & Spottiswoode for H.M.S.O., 1884?).
Gill, David, “Observations of Comet 1884 II (Barnard),” Astr. Nach. 110, 201-206 (1884).
Gill, David, “Photographie Céleste. Traduction d’une Lettre adressée par M. le Dr. Gill, directeur de l’observatoire du Cap, à M. Mouchez, relativement au project d’exécution d’une Carte photographique du Ciel,” Bulletin Astronomique, Serie 1, 3, 321-24 (1886).
Gill, D., “On Some Suggested Improvements in the Practical Working of M. Loewy’s New Method of Determining the Elements of Astronomical Refraction,” MNRAS 46, 325-28 (1886).
Gill, D., “On the Determination of Errors of Graduation without Cumulative Error, and the Application of the Method to the scales of the Cape Heliometer,” MNRAS 49, 105-18 (1886).
Gill, David, “Note on some investigations of the accuracy of the Paris photographs,” Observatory 11, 292-96 (1888).
Gill, David, “On the Reduction of Distances from Heliometer Observations,” Astr. Nach. 131, 185-92 (1892).
Gill, David & J.C. Kapteyn, The Cape Photographic Durchmusterung for the Equinox 1875 (H.M. Stationery Off., London, 1896).
Gill, David, Observations of Comets made at the Royal Observatory, Cape of Good Hope, in the Years 1880 to 1894Annals of the Cape Obs., vol. 1, part 1 (H.M. Stationery Office, Edinburgh, 1898).
Innes, R.T.A., Reference Catalogue of Southern Double Stars, with a preface by David Gill Annals of the Cape Obs., vol. 2, part 2 (H.M. Stationery Office, Edinburgh, 1899).
Gill, David, Researches on Stellar Parallax Made with the Cape Heliometer (H.M. Stationery Office, Edinburgh, 1900).
Gill, David, “The Great Comet of 1901, as Observed at the Royal Observatory, Cape of Good Hope,” MNRAS 61, 508-12 (1901).
Gill, David, “Preliminary Note on an Apparent Rotation of the Brighter Fixed Stars as a Whole with Respect to Fainter Stars as a Whole,” Astr. Nach. 159, 117-122 (1902).
Gill, David, Results of Meridian Observations of the Sun, Mercury and Venus Made at the Royal Observatory, Cape of Good Hope, in the Years 1884-1892 (H.M. Stationery Office, Edinburgh, 1907).
Gill, David, “On the Construction of Astronomical Instruments,” Transactions of the Optical Society 13, 64-97 (1911).
Gill, David, W.H. Finlay, W. de Sitter, & V.A. Lowinger, “Researches on Stellar Parallax Made with the Cape Heliometer,” Annals of the Cape Observatory 8, 2.i-2.175 (1911).
Gill, David, “President’s Address,” MNRAS 71, 380-85 (1911).
Cookson, Bryan & David Gill, “Determination of the Mass of Jupiter and Orbits of the Satellites from Observations Made with the Cape Heliometer,” Annals of the Cape Observatory 12, 2.1-2.215 (1915).
Cookson, Bryan & David Gill, “Determination of the Elements of the Orbits of Jupiter's Satellites: from photographs taken at the Cape in 1902,” Annals of the Cape Observatory 12, 4.1-4.122 (1915).
Gill, David, William Finlay, & Willem de Sitter, Determination of the Mass of Jupiter and Elements of the Orbits of Its Satellites from Observations Made with the Cape Heliometer (H.M. Stationery Office, Edinburgh, 1915).
Other Works: Popularizations, History, etc.
Gill, David, “The Cape Observatory,” Observatory 11, 85-87 (1888).
Gill, David, “The Photographic Chart of the Heavens,” Observatory 11, 320-26 (1888).