Charles Green was born in 1735 in Yorkshire, the son of a farmer. In 1761 he was appointed Assistant to the third Astronomer Royal, the Rev. James Bradley, successor to Halle, at the Royal Observatory Greenwich, founded in 1675.
This position was described thus: "Nothing can exceed the tediousness of the life the assistant leads, excluded from all society, forlorn, he spends months in long wearisome computations". It was hardly surprising that Green took the opportunity to take special responsibility for the observations of the Transit of Venus on Cook's first great voyage.
In November, 1763 "two gentlemen well skilled in astronomy'' sailed for Barbados. One was Green and the other was Rev. Nevil Maskelyne, who had observed the 1761 Transit of Venus in St Helena. Maskelyne was appointed as chaplain to HMS Princess Louisa and to help Green with the tests. Maskelyne, author of "British Mariners Guide', wrote a very favourable report on Green. They returned home in autumn 1764, and on the death of Nathaniel Bliss, Maskelyne became Astronomer Royal and Green got a salary increase. Green had a disagreement with his superior and entered the navy. He was purser of the Aurora before going to the Endeavour in 1768.
It was hoped that observations of the Transit of Venus would provide the vital distance which could give scale to the solar system. As the official astronomer to the expedition, Green was to receive 200 guineas for his work, whilst Cook got 100 guineas. Green's servant on the voyage was John Reynolds. In Tahiti Green made observations and checked instruments ready for the Transit of Venus on June 3rd 1769. Cook wrote "not a clowd seen the whole day, and air perfectly clear, so we had every advantage we could desire in observing the whole passage of the planet Venus over the suns disk".
Originally published in Cook's Log, page 1713, volume 23, number 1 (2000).