London, The Royal Society, 1772. 4to [22.3 (title page 21.5) x 16.9 cm)]. Title page, four pp. Disbound.

One of the chief objectives of James Cook' s first voyage was the observation of the transit of Venus in order to measure the distance between Venus and the sun, and hence between the Earth and the sun (the other was to explore the mysterious South Land). This paper is a report of the results. The Dutch scientist Johan Maurits Mohr (1716-1775) edited the data collected and forwarded by Cook and communicated it to the Royal Society. Mohr resided in Batavia, one of the stops of Cook's first voyage. “In 1765 Mohr built a large private observatory that was equipped with the best astronomical instruments of his time. His observatory, which had cost him a small fortune, was visited and praised by Louis Antoine de Bougainville and James Cook” (Wikipedia). Published in the Society's Philosophical Transactions. Title page of the part included. A good, clean copy. Although one of the most important scientific contributions by Cook, it was, apparently, missed by Beddie, Bibliography of Captain James Cook.