1769 Transit of Venus observed from Tahiti while voyaging to (unsuccessfully) observe the 1761 Transit in Sumatra. Using the solar parallax values obtained from the 1769 transit, Hornsby wrote in "Philosophical Transitions" December 1771 that "the mean distance from the Earth to the Sun (is) 93,726,900 English miles." The radar-based value used today for the astronomical unit is . This is only a difference of eight-tenths of one percent. Considering what these astronomers had to work with, their results were "absolutely remarkable". 1769 Transit of Venus observed from Tahiti On June 3, 1769, British navigator Captain James Cook, British naturalist Joseph Banks, British astronomer Charles Green and
John McLeod (explorer) John McLeod (explorer) John McLeod (1795 – after 1842) was a Scottish-born explorer of Canada, in his capacity as a fur trader with the North West Company and Hudson's Bay Company. He is remembered primarily for his explorations of several major rivers of the southwestern Northwest Territories, southern Yukon Territory, and northern British Columbia. McLeod arrived in Montreal, headquarters of the North West Company, in 1816. From there, he was assigned to the Churchill River area as a clerk. Following the merger of the two fur trading companies in 1821, McLeod served at various posts in the Athabasca and Mackenzie