The most ancient records we possess from Assyria, Egypt, Palestine, and from the Homeric poems, show how very limited was the range of geographical knowledge possessed by that small civilised world from which our own civilisation has descended. Speaking roughly, that knowledge seems in the tenth century B.C. to have extended about one thousand miles in each direction from the Isthmus of Suez. However, the best point of departure for the peoples of antiquity is the era of Herodotus, who travelled and wrote B.C. 460-440. The limits of the world as he knew it were Cadiz and the Straits of Gibraltar on the west, the Danube and the Caspian on the north, the deserts of Eastern Persia on the east, and the Sahara on the south, with vague tales regarding peoples who lived beyond, such as Indians far beyond Persia, and pygmies beyond the Sahara. He reports, however, not without hesitation, a circumnavigation of Africa by Phœnicians in the service of Pharaoh Necho. [Illustration: THE FIRST KNOWN MAP OF THE WORLD This Babylonian map is probably of the eighth century B.C. The two circles are supposed to represent the ocean, while the River Euphrates and Babylon are shown inside them. The upper part of the tablet is a cuneiform inscription. ] Discovery advanced very slowly for many centuries, though the march of Alexander opened up part of the East, while the Roman conquests brought the Far North-West, including Britain, within the range of civilisation; and occasional voyages, such as that of Hanno along the coast of West Africa, that of Nearchus through the Arabian Sea, and that of Pythias to the Baltic, added something to knowledge. Procopius in A.D. 540 can tell us little more regarding the regions beyond Roman influence than Strabo does five and a half centuries earlier. The journeys of Marco Polo and Rubruquis throw only a passing light on the Far East. It is with the Spanish occupation of the Canary Isles, beginning in 1602, and with the Portuguese voyages of the fifteenth century, that the era of modern discovery opens. The re-discovery of America in 1492, for it had been already visited by the Northmen of Greenland and Iceland in the eleventh century, and the opening of the Cape route to India in 1497-1498, were hardly equal to the exploit of Magellan, whose circumnavigation of the globe in 1519-1520 marks the close of this striking period. Thereafter discovery proceeds more slowly. Some of the isles of the central and southern Pacific were not visited till the middle of the eighteenth century, and the north-west coast of America as well as the north-east Coast of Asia, remained little known till an even later date. Those explorations of the interior of North America, of the interior of Africa, of the interior of Australia, and of East Central Asia, which have completed our knowledge of the earth, belong to the nineteenth century. The first crossing of the North American Continent north of latitude 40° was not effected till A.D.