b'The first measurements of gravity in Australia Featureastronomer Maskelyne\x08 Maskelyne mentored William Dawes and supplied him with the instruments used to produce the first published measurements of gravity in Australia (Morrison and Barko, 2009)\x08 It is not known if Dawes used an instrument that was already well travelled, but it is possible\x08ReferencesDay, A\x08A\x08, 1966-67\x08 The development of geophysics in Australia: Journal and Proceedings of the Royal Society of NSW, 100, 33-60\x08De Freycinet, L\x08S\x08, 1826\x08 Voyage autour du monde, 1817-1820\x08 Observations du pendule: Paris\x08 Pillet Ain, 292 pp\x08Henderson, R\x08, 2020\x08 Bouguers gravity corrections and the shape of the Earth\x08 Preview, 208, 39-43\x08Morrison, D\x08 and Barko, I\x08, 2009\x08 Dagelet and Dawes: Their Meeting, Their Instruments and the First Scientific Experiments on Australian Soil: Historical Records of Australian Science, 20, 1-40, CSIRO publishing for Australian Academy of Science 2009\x08 Figure 1.This sketch of Sydney Cove with coastline drawn by W. Dawes hashttp://www\x08publish\x08csiro\x08au/nid/108/paper/HR09002\x08htmthe position of the observatory on the northernmost headland on the westernLaurie, P\x08S\x08, 1988\x08 William Dawes, and Australias first side of the Cove. The headland on the eastern side is Bennelong Point (afterobservatory: Quarterly Journal of the Australian Astronomical Laurie, 1988). Society, 29, 469-482\x08 http://articles\x08adsabs\x08harvard\x08edu//full/1988QJRAS\x08\x0829\x08\x08469L/0000469\x08000\x08htmllongitude\x08 Of more interest to geophysicists, however, are hisBosloper, C\x08, 2010\x08 William Dawes gravity measurements in readings of gravity\x08 Morrison and Barko (2009) were able toSydney Cove, 1788: International Federation of Surveyors establish that Dawes, over a period from February 1788 to earlyCongress 2010\x08 11-16 April, 2010, Sydney, Australia\x081790, also undertook observations specifically to determine (theKater, H\x08, 1823\x08 An account of experiments made with an value of) gravity at his Sydney Cove observatory\x08 The valuesinvariable pendulum at New South Wales by Major-General were forwarded to Dr Maskelyne in Britain who calculatedSir Thomas Brisbane, K\x08C\x08B\x08, F\x08R\x08S\x08: Phil. Trans. Roy. Soc. Lond., the absolute gravity\x08 (Morrison and Barko, 2009)\x08 Thus, unlike113, 308-325\x08Dagelet, the French observer of gravity, Dawes results survived,King, R\x08J\x08, 1990\x08 The Secret History of the Convict Colony: Alexandro making them the first gravity measurements in Australia\x08 Malaspinas report on the British settlement of New South Wales. Morrison and Barko (2009) were finally able to confirm that WilliamAllen & Unwin, Sydney, 1990\x08 ISBN 0-04-610020-2\x08Dawes gravity readings, after correction by C\x08 Bosloper (2020), resulted in the value at Sydney Cove as 9\x0879705 m/s2 or 979\x08705 gal\x08 This value agrees well with current absolute determinations12\x08Finally, it can be noted that Captain James Cook made clock measurements on his second voyage on the Resolution (1772-75) that enabled gravity to be derived at a number of ports of call (for a list of locations see Bosloper, 2010 -Table 3)\x08 If Cook had had the requisite equipment on his first voyage on Endeavour (1768-71) he may have been able to make similar measurements when he was moored for a time at Botany Bay in 1770\x08 They would certainly then have been the first known determinations of gravity in Australia\x08It is interesting to observe that scientists in the eighteenth century, the age of enlightenment, shared their few priceless astronomical instruments\x08 Instruments were even shared between warring countries such as Britain and France\x08 Morrison and Barko (2009), in their detailed revelations about the visit of the La Perouse expedition to Sydney (1785-87) to measure gravity, suggest that one of the three astronomical clocks (pendulums) used by the astronomer Dagelet was also used by Pierre Bouguer and Charles-Marie de La Condamine on their expedition to Peru (1736-45) to measure the shape of the earth (see Henderson 2020)\x08 The measurements of plumb-line deviations due to mountain masses in Peru made by Bouguer and Condamine were verified in 1774 in Scotland by the British 12According to C\x08 Bosloper (2020), Dawes made a mistake in setting the pendulum nut wrong by a whole turn, which effectively shortened the pendulum length\x08 As this has been noted to have occurred on subsequent voyages by Captain Cook and others, Bosloper was able to correct this\x0849 PREVIEW APRIL 2021'