A fine large chart of the Pacific showing the western coast of America north to the tip of the island of California and south to Tierra del Fuego. One of only two charts of the Pacific published in England before 1740. The map is not recorded in any of the standard references to California as an island, and is not listed by Wagner. Only two other known examples could be traced – one privately, and that in a Samuel Thornton composite atlas at The New York Public Library. The earliest modern chart of the Pacific was published as an atlas map by Joannes Jansson in 1650. It was closely copied by Arnold Colom in 1658 with editions to 1700. In 1675 John Seller published the first English chart of the whole Pacific region again following the early Dutch models. Not until 1683, with John Thornton’s “A New MAPP of the / WORLD…Mercator’s Projection.”, do the English maps of this area begin to take on character of their own. By the beginning of the 18th century the Dutch models were obsolete. About the time of his uncle’s death Samuel Thornton re-published many of John Thornton’s charts along with several new ones designed to compete with The English Pilot: Fourth Book. These were bound in composite atlases, often with a title page Atlas Maritimus. In this respect he followed John Seller’s original design for a composite English sea atlas of the world. The chart of the Pacific was new and probably published soon after his uncle’s death in 1704. The cartography laid down on this chart is advanced. Unlike other London publishers who reiterated the Dutch and French cartography (Moses Pitt, John Overton, Phillip Lea, etc.), Thornton used surveys first published on the large wall map of the world by Robert Morden, 1699 (Shirley # 597). Like other English charts of the Pacific Thornton depicts English settlements in America from Florida to New England as well as the Pacific rim. South America takes on a familiar elongated form and the California coast, although largely following the second Sanson model, is distinctly English. The South Pacific islands are similar to earlier printed maps but an informed comparison of the nomenclature between the Dutch and English charts has yet to be published. (A first state with the imprint of John Thornton survives in BL Maps.C.25.b.9). Burden. North America, # 292 (Jansson)/ Shirley. World, # 597 (Morden)/ Tooley. California as an Island, # 38, plate 45 (Seller).