Cook’s third voyage, which was undertaken primarily with the idea of forcing a way through the north-west passage, has already been mentioned in the chapter on Polar Exploration. But it must be noticed here that on his way to the Arctic region, besides revisiting many of his previous discoveries and finding the larger islands of the Cook Archipelago, he sighted for the first time since the sixteenth century the Hawaiian group. These important islands are supposed to have been discovered by the Spaniard Gaetano in 1555, but had long been forgotten; it was here that Cook was murdered by the natives in 1779. His work was of extreme importance in several directions: he made known to the world a larger area of the globe than perhaps any other man before or since; he overcame the disease which had previously been one of the greatest obstacles in the way of explorers, and he laid the foundation of the British Australasian Empire. It is said that had he returned from his last voyage he would have received honour from the King; it would have been due, and overdue. Cook’s work in the Pacific was ably carried on after his death by several other explorers, of whom the best known was J. F. G. de la Pérouse, who set out in 1785 to fill in the gaps left by Cook on his voyages, and particularly to explore the great sea between North-west America and Japan. He made a successful exploration of Manchuria and the islands to the north of Japan, which were then little known, and he visited Petropavlovsk in Kamchatka, whence he sent home the journals of his voyage. He then voyaged to the east of Australia, touching at Samoa, and reached Botany Bay. Then disaster overtook the expedition, and no one returned to tell how its members perished somewhere to the north of the New Hebrides. In 1791 d’Entrecasteaux set out to search for La Pérouse; and though he was unsuccessful, he advanced to a large extent the knowledge of the islands north-east of Australia. During the following hundred years many explorers and scientists worked in the Pacific, filling in the gaps left by the pioneers in the region. In 1803 the Russians came on the field, with Adam Krusenstern, followed by Otto von Kotzebue (1816), and Fabian von Bellingshausen (1819–21). The French followed in 1818 with L. C. D. de Freycinet, and later with Louis Duperrey and Dumont d’Urville. In 1839 the first important American expedition sailed under Charles Wilkes. Much scientific work for purposes of research was carried on in Oceania in the nineteenth century; but with the exception of the famous “Challenger” expedition (Chapter XIV) it is beyond the scope of this book. CHAPTER X. MEASUREMENT, CARTOGRAPHY, AND THEORY, 1500–1800