At the same time he addressed a treatise to the Royal Society of London, upon an eclipse of the sun, which he had observed in Newfoundland in 1766.
This document appeared in the "Philosophical Transactions." Cook was not long in receiving a due reward for so much, and such successful labour, and for his patient studies, the more meritorious, as he had had few opportunities, and was self-taught.
A scientific question of the highest importance, viz., the transit of Venus across the sun's disc, which had been announced for 1769, was eagerly discussed by all the scientists of the day. The English Government, confident that this observation could only be effectually made in the Pacific Sea, resolved to send a scientific expedition thither.
The command was offered to the famous hydrographer A. Dalrymple, equally celebrated for his astronomical investigations, and his geographical discoveries in the southern seas. But he was so exacting in his demands, and so persevering in his request for a commission as ship's captain, which Sir Edward Hawker as obstinately refused, that the Secretary of the Admiralty proposed another commander for the projected enterprise.
His choice fell upon James Cook, who was cordially recommended by Sir Hugh Palliser, and to him therefore the command of the Endeavour was given, whilst he was at the same time raised to the rank of ship's lieutenant.
Cook was now forty years of age. This was his first appointment in the Royal Navy. The mission entrusted to him called for varied qualifications, rarely to be met with in a sailor. For, although the observation of the transit of Venus was the principal object of the voyage, it was by no means the only one. Cook was also to make a voyage of discovery in the Pacific Ocean. But the humbly born Yorkshire lad was destined to prove himself equal to his task.
Whilst the Endeavour was being equipped, her crew of eighty-four men chosen, her store of eighteen months' provision embarked, her ten guns and twelve swivel guns, with the needful ammunition, shipped, Captain Wallis arrived in England. He had accomplished his voyage round the world. He was consulted as to the best spot for the observation of the transit of Venus, and he selected an island which he had discovered, and which was named by him after George III. It was later known by its native name of Tahiti. From this spot therefore Cook was to take observations.
Charles Green, assistant to Dr. Bradley, of Greenwich Observatory, embarked with him. To Green was entrusted the astronomical department, Doctor Solander, a Swedish doctor of medicine, a disciple of Linnæus, and professor at the British Museum, undertook the botanical part. Finally, Sir Joseph Banks joined the expedition, out of simple interest, anxious to employ his energy and fortune. After leaving Oxford, Sir Joseph Banks had visited the Newfoundland coast and Labrador, and had there acquired a taste for botany. Two painters accompanied the expedition, one a landscape and portrait painter, the other a scientific draughtsman. In addition to these persons, the company comprised a secretary and four servants, two of whom were negroes.
The Endeavour left Plymouth upon the 26th of August, 1768, and put into port at Funchal, in the island of Madeira, on the 13th of September, to obtain fresh fruit and make discoveries. The expedition met with a cordial reception.
During their visit to a convent, the staff of the Endeavour were entreated by the poor immured recluses to let them know when it would thunder, and to find a spring of fresh water for them, which they sorely needed, in the interior of the convent. With all their learning, Banks, Solander, and Cook found it impossible to satisfy these demands.