Within 20 years from the time of Gama's arrival in India, the coasts of E. Africa, Arabia, Persia, Hindustan, and Further India had been explored, and many of the islands of the great archipelago discovered. In the 10th and 17th centuries the progress of astronomical science led to a general revision of Ptolemy's tables of latitude and longitude, which had for ages been received with implicit confidence, but which more accurate observations now proved to be generally erroneous. In the 18th century many learned and laborious writers, among whom D'Anville may be particularly mentioned, applied themselves to the rectification of the whole system of ancient geography, and to the identification of ancient with modern countries, cities, rivers, mountains, and other features. The desire to discover a shorter route to India than those by Cape Horn and the cape of Good Hope led the English and the Dutch in the 16th century to make daring and persevering efforts to effect a N. E. and a N. W. passage. For a long time the opinion prevailed that the northern extremity of America terminated, like the southern, in a point or cape, by sailing around which the mariner could enter the Pacific ocean and make his way to India. The expeditions of Sir Hugh Willoughby and Richard Chancellor in 1553, of Frobisher in 1576-'8, of Davis in 1585-'7, of Barentz in 1594-'6, in search of this northern route, greatly enlarged the knowledge of the arctic regions, and especially of the N. E. part of North America. So, too, in the succeeding century, a similar result followed from the voyages of Henry Hudson in 1607-'11, and of William Baffin in 1612-16. It was not till the latter part of the 18th century, however, that the great breadth of the upper part of North America became fully known from the investigations of Capt. Cook in his voyages to the Pacific. The determination of the distance from Behring strait to the E. coast of North America dispelled for a time all expectation of a X. W. passage; it was supposed that the continent stretched in one unbroken mass to the pole.

The discoveries of Ilearne in 1771 and of Mackenzie in 1789, by showing that an ocean bounded America on the north, dispelled these ideas, and in 1818 the attempt to effect the X. W. passage was revived by an expedition commanded by Capt. Ross. This was the beginning of a series of English and American expeditions to the arctic regions which have greatly advanced our knowledge of that part of the world, though without attaining the object for which they were commenced. (See Arctic Discovery.) Early in the 17th century the Dutch, while seeking for a southern continent whose existence was supposed necessary to balance the northern, discovered Australia, which they called New Holland, and explored a considerable portion of its coasts. In 1642

Tasman discovered Van Diemen's Land, or Tasmania, as it is now called. Soon afterward he discovered New Zealand and several of the Polynesian groups. His explorations proved that New Holland was an island, and not a part of the southern continent. The famous Capt. Cook in his voyages, 1768-'79, made strenuous efforts, without success, to discover the southern continent; but he added largely to geographical knowledge by his survey of the Pacific ocean and its innumerable islands. An expedition sent out by the United States in 1838, under command of Lieut. Wilkes, in 1842 discovered a continent within the antarctic circle, portions of which had been seen shortly before by the French and English navigators Dumont d'Urville and Sir James Ross. (See ANtaec-tic Discovery.) Our acquaintance with the interior of Asia has been greatly advanced within the last two centuries by Russian, English, and French conquests, and by a multitude of travellers, prominent among whom have been the Jesuit missionaries, so that our general knowledge of that continent is tolerably complete. No great terra incognita remains, though fuller and more precise information about the vast regions known as Tartary is much to be desired.

The travels of Humboldt, of Lewis and Clarke, and of Fremont have enlarged our acquaintance with the interior of the American continent; and during the last few years much light has been thrown upon it by the various exploring expeditions sent out by the government, and especially by companies of professors and students from our colleges. The interiors of Australia and of Africa are still only partially known. Much has been done for the exploration of the former by Sturt, Eyre, Leichardt, Stuart, McKinlay, Landsborough, Burke, the brothers Gregory, and others; while in Africa a host of travellers have struggled for a century past to penetrate the mystery which envelops that great division of the globe. Foremost among the African explorers have been James Bruce, Mungo Park, Major Denham, Lieut. Clapper-ton, Richard Lander, Captains Burton and Speke, Dr. Livingstone, Dr. Barth, Heuglin, and Sir Samuel Baker. Great additions to our knowledge of the countries on the upper Nile have been made by expeditions sent by the pasha of Egypt, which have penetrated far beyond the region so long assigned on our maps to the mountains of the Moon. These expeditions and the researches of Barth, Burton, Livingstone, Baker, and the missionaries Rebmann and Krapf, have left in obscurity only a portion of that part of Africa which lies between lat. 10° N. and 10° S., and Ion. 12° and 27° E. Dr. Livingstone at the time of his death was endeavoring to penetrate this region.-The remarkable progress of geographical discovery during the present century may be thus briefly summed up: Northern Asia has been traversed by the expeditions sent out by the Russian government; the great fields of central Asia have been crossed in various directions; our knowledge of China has been vastly increased; the newly awakened desire of the Japanese to participate in the advantages of European civilization has broken down much of their ancient prejudice against foreigners, and bids fair to introduce us to an intimate and exact knowledge of their country; Palestine has been explored with wonderful minuteness; the interior of Arabia has been penetrated; the sites of many of the most renowned cities of antiquity have been determined; the Niger and the Benoowe or Tchadda have been traced almost throughout their extent; the Kile has been traced to the great lakes in the equatorial regions of Africa; Madagascar and Australia have been crossed in various directions from sea to sea; the icy continent about the south pole has been discovered; the delineation of the N. shore of the North American continent has been completed; the principal features of the geography of that vast portion of our own territory lying between the Mississippi and the Pacific have been ascertained, and its sublime scenery has been described; and the river systems of South America have been explored.

With the exception of the regions about the poles and in the centre of Africa, the general outlines of every part of the earth's surface are known to civilized man. -The literature of geography, to which the school of Carl Ritter has given its highest degree of scientific development, has within a few years undergone a marked change. Instead of the formal, regular descriptions of the earth and its inhabitants, which were once in vogue, gazetteers and geographical dictionaries are now popular. The progress of geography has been much aided during this century by the efforts of zealous geographical societies. Their transactions, issued periodically, contain a vast and constantly increasing mass of information. Among the best works on geography are: Geographie universelle, by Malte-Brun (6 vols. 8vo, Paris, 1810-'29; revised by Th. Lavallee, 6 vols. 8vo, 1856-'62), the English translation of which was revised by J. G. Pcrcival, who added notes (3 vols. 4to, Boston, 1834); Die Geschichte der Erdkunde, by Ludde (1840); Geschichte der Erdlcunde und Ent-deckungen, by Carl Ritter (1861); Geschichte der Erdlcunde his avf Alexander von Humboldt und Carl Hitter, by O. Peschel (18G5); and the works of De Rougemont, Von Roon, Berg-haus, Volger, Merleker, Meinicke, Kloden (Handbuch der Erdkunde, 1858-'62; 2d ed., 1865 et seq.), Wappaus {Handbuch der Geographic und Statistik, 4 vols., 1855-71), and Daniel {Ilandbuch der Erdkunde, 4 vols., 3d ed., 1869-'72). Eor ancient geography, see Handbuch der alten Geographie, by Forbiger (3 vols., 1842); Smith's "Dictionary of Greek and Roman Geography (2 vols. 8vo, London, 1854-7); Buchholz's Homerische Kosmogra-jdiie und Geographie (1871); and Deutsche Alterthumslcunde: Stellung des Pytheas in der Geschiclite der Erdkunde, by K.Miillen-hoff (1870). The principal geographical gazetteers and dictionaries are: "Encyclopaedia of Geography," by Hugh Murray (London, 1834; Amer. ed. revised, 3 vols. 8vo, Philadelphia, 1843; new ed., 1857); "A Dictionary, Geographical, Statistical, Historical," etc, by J. R. McCulloch (4 vols. 8vo, London, 1841; new ed., 1866); Fullarton's "Gazetteer of the World " (7 vols. 8vo, Edinburgh, 1850-'57); " The Imperial Gazetteer," by W. G. Blackie (2 vols., London, 1855; 3d ed., 1873); Ritter's Geogra-phisch -statistisches Lexikon (Leipsic, 1855); Lippincott's " Gazetteer of the World " (Philadelphia, 1855; new ed., 1866); Keith Johnston's " Dictionary of Geography " (revised ed., London, 18G7); Dictionnaire de geographie ani-verselle, ancienne et moderne, by L. N. Besche-relle (4 vols. 4to, Paris, 1856-'8; new ed., 1865); and Dictionnaire universel d'histoire et de geographic, by M. N. Bouillet (1 vol., Paris, 1842; 22d ed., 1871). Most of the geographical societies publish periodicals, the principal of which are those of Paris {Bulletin, 1822 et seq.), London ("Journal," 1831 et seq.; "Proceedings," 1855 et seq.), Berlin {Zeitschrift, 1840 et seq.), St. Petersburg (1848 et seq.), Geneva {Journal, 1861 et seq.), and Florence {Bollet-tino, 1867 et seq.). Other valuable geographical periodicals are Petermann's Geographische Mittheilungen (Gotha, 1855 et seq.), and its Er-gangzungshefte or supplements; Saint-Martin's L'Annee geographique (Paris, 1863 et seq.); and "Ocean Highways" (London, 1871; new series, 1873 et seq.).