b'The first measurements of gravity in Australia FeatureThe first measurements of gravity in AustraliaMalaspina seated alongside\x08 The caption included experiments were made wherever the expedition landed, including Sydney4\x08Further detail on this supposition is given in the introduction of King (1990 p2): Bennelongs hut, on the east point of Sydney Cove, was assigned to the visitors to store their instruments while they made astronomical and gravitational observations and (p3): Before the expedition left Sydney, the results of all their scientific observations and calculations were made available to the English officers5\x08 What happened to these results? And did they include determinations of gravity?Well-known ASEG historian Doug Morrison and his colleague, Ivan Barko, carried out extensive research and were able to Roger Hendersonreport (Morrison and Barko, 2009) that the earliest gravity rogah@tpg.com.au determinations in Sydney Cove (and therefore in Australia) with surviving results were made by William Dawes in 1788\x08 Other measurements may have been made a few days earlier by the In his comprehensive history of geophysics in AustraliaFrench astronomer J\x08 L\x08 Dagelet in Botany Bay, but his results DrAA Day (Day, 1966) first refers to gravity measurementswere lost when his ship was wrecked on its way home to France6\x08being made in Sydney by L\x08 S\x08 de Freycinet and his company in 1819\x08 They used pendulums1\x08 Freycinet was, however,William Dawes came to Sydney in 1788 as a Lieutenant of Marines unable to compile his results for publication until 1826on the First Fleet transporting convicts7\x08 He was supplied with (deFreycinet, 1826)\x08 the necessary navigational and astronomical equipment by the British Astronomer Royal, Rev Dr Nevil Maskelyne8\x08 Maskelyne had Day (1966) states they were the first of four determinationspersuaded the Board of Longitude that the equipment could be of gravity to be made there in a space of ten years withoutused to observe a comet that was expected to return in September giving any more information\x08 He then notes that when1788, and which would be best seen in the Southern Hemisphere9\x08 Sir Thomas Brisbane arrived at Port Jackson in 1821 to beMaskelyne had nominated Dawes to operate the equipment; Governor of the Colony, he and his assistant, J\x08 Dunlop, soonhowever, the Board requested that the equipment be entrusted swung the Kater pendulum that Brisbane had brought fromonly to Captain Arthur Phillip, the commander of the First Fleet London at the new observatory Brisbane had established(Laurie, 1988)\x08 This decision was later to lead to some episodes of at Parramatta2\x08 As he had swung the Kater pendulumdisagreement between Dawes and Phillip, and ultimately to Dawes before leaving London, Brisbane was able to determinebeing sent back to England after only three years10\x08the difference in gravity between London and Parramatta\x08Very soon after his arrival, Dawes set up an observatory, according The results were forwarded to Henry Kater in England whoto a model recommended by Maskelyne, on what is today known published them in 1823, three years before de Freycinetas Dawes Point - adjacent to the southern pylons of Sydney published his (Kater, 1823)\x08 Harbour Bridge \x08 Figure 1 is a sketch of the area surrounding 11Recent research and later publications than Day (1966) suggestSydney Cove including the location of the observatory\x08that determinations of gravity had taken place in Sydney earlier than those made by de Freycinet\x08 For example, the MalaspinaThe comet that Maskelyne had predicted that Dawes could Expedition (17891794), a five-year maritime scientificobserve with his instruments did not appear, but Dawes exploration from Cadiz, Spain, under the command of Donnevertheless made the usual measurements of latitude and Alexandro Malaspina di Mulazzo, visited Sydney for a month from 13 March to 12 April, 17933\x08 It is presumed that Malaspina4Also, in First Geophysical Measurement at Sydney in 1793? in Preview had swung a pendulum there, as they had swung a pendulumOctober 1991 p 15 (as reprinted from NZ Geological Society, Historical at various places on the voyage from Cadiz for purposes ofStudies Group Newsletter March 1991), is a comment by Malaspina that determining the figure of the Earth\x08 experiments on gravitation have been repeated in both hemispheres and in various latitudesSome grounds for this presumption include the caption to a5Bennelongs hut was on Bennelong Point, now the site of the Sydney Opera figure in King (1990, p 66), a translation of Malaspinas report onHouse\x08 See Figure 1\x08the British settlement, which shows a pendulum in a tent with6Joseph Lepaute Dagelet was the astronomer of the La Prouse expedition of 1785-1787, which was under the command of Jean-Francois de Galaup de La Prouse and left Sydney on 10 March 1788 never to be seen again by any British or French citizen\x08 Much more on this French connection is in Morrison and Barko (2009)\x081Louis-Claude de Saulces de Freycinet was in command of lUranie\x08 He7Biographies and other details on Dawes include; Dawes, William (1762-conducted scientific observations around the world (1817-1820) and1836), Aust\x08 Dictionary of Biography; Laurie, 1988\x08visited Port Jackson (Sydney) in December 1819 to make gravity and8For a detailed list of the equipment supplied see Laurie, 1988 p 470\x08magnetic measurements\x08 9The Board of Longitude was a body created by an Act of Parliament in 1714 2The observatory was established by Brisbane at his own expense in theto study aspects of navigation\x08grounds of Government House at Parramatta\x08 10In part, Phillip was too protective of the equipment on occasions on the 3The definitive account of the expedition was finally published as; Museo Navalvoyage out when Dawes could have used it\x08y Ministerio de Defensa, La Expedicin Malaspina, 1789-1794, Barcelona,11Originally, Captain Phillip named the area Point Maskelyne\x08 The coordinates Lunwerg, tomos 1-9, 1987-1999\x08 of the location as best estimated are: 33 51 25 S, 151 12 30 E\x08APRIL 2021 PREVIEW 48'