Alexander Dalrymple's chart records the tracks of a number important voyages of discovery, funded by competing nations, in the South Pacific: Alvaro Mendana de Neyra, discoverer of the Solomon Islands, in 1595; Theodore Gerrards, who claimed to see mountains southwest of South America in 1599; Pedro Fernandes de Quiros and Louis Vaez de Torres in 1606, showing them traversing what is now known as Torres Strait, although the source of this assertion is not provided in the book. The evidence had in fact come from his study of original documents and charts of Torres taken by the British from the Spanish archives when they captured Manila in 1762; Jacob Le Maire and Willem Schouten's discovery of the strait named after Le Maire, and crossing of the Pacific, in 1617; Jacob Roggeveen, who found Easter Island, in 1622; and Abel Tasman's voyages of 1642 and 1644.

The plate was originally engraved for Dalrymple's rare 'An account of the discoveries made in the south Pacifick Ocean, previous to 1764' (1767), and subsequently reprinted widely in his 'An Historical Collection of the Several Voyages and Discoveries in the South Pacific Ocean' (1770-1771). This French edition was probably, according to the National Library of Australia, included in the 'Atlas universal pour l'etude de la geographe et de l'histoire ancienne et moderne par Mr. Philippe et autres auteurs' (1787).

The mapmaker
The first hydrographer to the British Admiralty, Alexander Dalrymple (1737-1808) is best known for his researches regarding a great Southern Continent, as well as a proponent of the search for the Northwest Passage (thereby influencing Vancouver's survey). Through family connections, Dalrymple was made a "writer" (the most junior position) for the East India Company and sent to Madras where he arrived in May 1753. He was afforded access to Robert Orme's library and grew increasingly fascinated with the EIC's activities in Burma, Indo-China and Borneo. He turned down a promotion so that he might undertake a voyage to the east of his own. "In February 1759, Pigot freighted the Cuddalore (Captain George Baker) for Dalrymple 'to attempt to discover a new route to China through the Molucca Islands and New Guinea'. Dalrymple made three voyages between 1759 and 1764 to the Philippines, Borneo, and Sulu. In the first, based at Canton (Guangzhou), he reconnoitred Borneo, the Philippines, and the coast of Cochin-China. For the second, in the London in 1762, he had James Rennell as companion for a voyage to Sulu and Balambangan, where he had obtained for the company a grant of land. In Madras in 1763 he went through the formality of resignation, confident of reinstatement, to return to London to promote a trading settlement at Balambangan. En route to Canton for passage to England he became provisional deputy governor at Manila for a short period in April 1764, in the aftermath of the treaty of Paris, and he arrived in London in the summer of 1765 …" (ODNB)