Diagram of the appearance of Venus at internal contact, as seen at Tahiti in 1769 by James Cook and Charles Green. From “Observations Made, by Appointment of the Royal Society, at King George’s Island in the South Sea; By Mr. Charles Green, Formerly Assistant at the Royal Observatory at Greenwich, and Lieut. James Cook, of His Majesty’s Ship the Endeavour”, Philosophical Transactions, 61 (1771), 397-421, facing p. 410.