During the Hellenistic Age men began to gain more accurate ideas regarding the shape and size of the habitable globe. Such events as the expedition of the "Ten Thousand" [17] and Alexander's conquests in central Asia and India brought new information about the countries and peoples of the Orient. During Alexander's lifetime a Greek named Pytheas, starting from Massilia, [18] made an adventurous voyage along the shores of Spain and Gaul and spent some time in Britain. He was probably the first Greek to visit that island. ERATOSTHENES, ABOUT 276-194 B.C. All this new knowledge of East and West was soon gathered together by Eratosthenes, the learned librarian of Alexandria. He was the founder of scientific geography. Before his time some students had already concluded that the earth is spherical and not flat, as had been taught in the Homeric poems. [19] Guesses had even been made of the size of the earth. Eratosthenes by careful measurements came within a few thousand miles of its actual circumference. Having estimated the size of the earth, Eratosthenes went on to determine how large was its habitable area. He reached the conclusion that the distance from the strait of Gibraltar to the east of India was about one-third of the earth's circumference. The remaining two-thirds, he thought, was covered by the sea. And with what seems a prophecy he remarked that, if it was not for the vast extent of the Atlantic Ocean, one might almost sail from Spain to India along the same parallel of latitude. [Illustration: PROGRESS OF GEOGRAPHICAL KNOWLEDGE IN ANTIQUITY Map, The World according to Eratosthenes, 200 B.C. Map, The World according to Ptolemy, 150 A.D.] PTOLEMY The next two centuries after Eratosthenes saw the spread of Roman rule over Greeks and Carthaginians in the Mediterranean and over the barbarous inhabitants of Gaul, Britain, and Germany. The new knowledge thus gained was summed up in the Greek _Geography_ by Ptolemy [20] of Alexandria. His famous map shows how near he came to the real outlines both of Europe and Asia. THE PTOLEMAIC SYSTEM Ptolemy was likewise an eminent astronomer. He believed that the earth was the center of the universe and that the sun, planets, and fixed stars all revolved around it. This Ptolemaic system was not overthrown until the grand discovery of Copernicus in the sixteenth century of our era. 46. THE GRAECO-ORIENTAL WORLD THE NEW LUXURY