Commodore Byron returned in the month of May in the year 1766, and in the month of August following the Dolphin was again sent out, under the command of Captain Wallis, with the Swallow, commanded by Captain Carteret. The equipment of the Dolphin was the same as before. The Swallow was a sloop mounting fourteen guns; her complement was ninety men, with one lieutenant and twenty-two petty officers. These vessels proceeded together till they came within sight of the South Sea, at the western entrance of the Strait of Magellan, and from thence returned by different routes to England. In the latter part of the year 1767, it was resolved by the Royal Society, that it would be proper to send persons into some part of the South Sea to observe a transit of the planet Venus over the sun's disc, which, according to astronomical calculation, would happen in the year 1769; and that the islands called Marquesas de Mendoza, or those of Rotterdam or Amsterdam,[2] were the properest places then known for making such observation. [Footnote 2: So called by Tasman, but by the natives Anamooka and Tongataboo; they belong to that large cluster which Cook named the Friendly Isles.--E.] In consequence of these resolutions, it was recommended to his majesty, in a memorial from the Society, dated February, 1768, that he would be pleased to order such an observation to be made; upon which his majesty signified to the lords commissioners of the Admiralty his pleasure that a ship should be provided to carry such observers as the society should think fit to the South Seas; and, in the beginning of April following, the society received a letter from the secretary of the Admiralty, informing them that a bark of three hundred and seventy tons had been taken up for that purpose. This vessel was called the Endeavour, and the command of her given to Lieutenant James Cook,[3] a gentleman of undoubted abilities in astronomy and navigation, who was soon after, by the Royal Society, appointed, with Mr Charles Green, a gentleman who had long been assistant to Dr Bradley at the Royal Observatory at Greenwich, to observe the transit.[4]