The close of the 18th century was the begin ning of a new era in the annals of American exploration, The travels ofAlexander von Humboldt between 1799 and 1804 in the basins of the Orinoco and Magdalena, and in the Andes and Mexican Cordilleras, mark an epoch in the history of geography and natural science. His work was taken up and extended to other regions, especially Brazil, by eminent natural ists like Maximilian of Wied, Spix, Martius, Auguste de Sainte-Hilaire, Orbigny and Poppig. These had worthy successors in the brothers Schomburgk (British Guiana), Darwin (Pata gonia, Tierra del Fuego), AvAallemant (Bra zil), Tschudi (Andes, Brazil), Castelnau (Bra zil, Bolivia, Peru), and Burmeister (Brazil, Argentina).
By the acquisition of the Louisiana territory in 1803 the United States came into possession of a boundless domain, in great part as far removed from the knowledge of white men as the heart of Africa. (See Fins. 5 and 6). An exploring expedition was immediately sent into this terra incognita under Lewis and Clark, who proceeded up the valley of the Missouri, crossed the divide of the Rocky Mountains and followed the Columbia down to the sea. The explorations of Pike, Long, Bonneville Catlin, Nicolett, and FrEttiont, the opening of overland routes to Utah and California, and the government sur vey for a Pacific railway made deep rifts in the trans-Mississippi region; but its greatest won ders were to remain enshrouded till the tide of colonization had begun to sweep over the whole area. It was not till 1832 that the Mississippi river was traced to its source by Schoolcraft.
The exploration of the Arctic regions in the hope of finding a north water route for the trade with the East, had lost much of its fasci nation by the 18th century. Russia alone prose cuted it systematically in the course of that cen tury, accomplishing a great work in tracing the coast line of Siberia. About the beginning of the 19th century the idea of a Northwest Pas sage was revived in England and the dream of reaching the pole began to be entertained. (See FIGS. 3 and 4). A great and persistent onslaught on the frozen North was inaugurated in 1818. The labyrinth of islands, peninsulas, and ice bound passages north of the American conti nent yielded up its intricacies to the assaults of Parry, the two Rosses, Sir John Franklin (to whose tragic end Arctic discovery owed much of its rapid progress), McClure, Kane, Mc Clintock and Hayes. The exploration of Arctic
British America was prosecuted on land with heroic energy by Franklin, Back, Richardson, Beechey, Dease, Simpson, and Rae. Parry in an attempt to reach the pole in 1827 dragged his sledges over the floating ice fields to the parallel of 82° 45', eclipsing all previous records by more than a degree of latitude. In 1831 James Clark Ross solved the mystery of the position of the north magnetic pole, which he located in the peninsula of Boothia. McClure entered the Arctic Ocean through Bering Strait in 1850, proceeded east, was beset for years in the ice, joined hands in 1854 with an expedition which had come in the opposite direction,, and thus carried off the laurels of the Northwest Passage. While a great breach' was being made in the Arctic fast nesses, Bellingshausen, Weddell, Dumont d'Ur ville, Sir J. C. Ross, Wilkes, and others ex tended geographical discovery into the Antarc tic regions. Ross discovered Victoria Land, with its active volcanoes, and in 1842 advanced beyond the 78th parallel. During this same period the arid depths of Australia, whose coast had been explored by Flinders in 1801-03, were invaded by Sturt, Eyre and the ill-fated Leichhardt.
A flood of light was thrown on the geog raphy of Northern and Central Asia in the first half of the 19th century by the journeys of Ermann, Humboldt, Middendorf, Huc (who entered Lhassa, the holy city of Tibet) and others; while men like Webb, Moorcroft and Wood scaled the heights of the Himalayas and the Pamir, and reached the head streams of the Indus, Ganges and Amu Dada. From 1848 Mount Everest, with the 29,002 feet given to it by the trigonometrical measurement of Sir Andrew Waugh, figured as the highest point on the globe. Among the naturalists who were attracted to the Himalayas, the name of the botanist Hooker stands pre-eminent. The most distinguished traveler in Southwestern Asia in the early part of the century was Burckhardt, who succeeded in entering the holy places of Mecca and Medina. In 1829 Ararat was ascended by Parrot. In 1832-33 Alex ander Burnes performed his famous ride from India to Bokhara. The travels of Crawfurd and MacLeod in the second quarter of the cen tury dispelled in part the obscurity hanging over farther India. Between 1835 and 1849 the naturalist Junghuhn explored Java and parts of Sumatra. Among his successors in the Malay Archipelago were St. John and Wallace.