The history of geographical discovery is, in its initial stages, almost solely one of conquest. Men, either for their own or their country's profit--and sometimes for both--went out in search of unknown lands because they wanted to trade with them. Pytheas, who has been described as "one of the most intrepid explorers the world has ever seen," was the first man to bring news of the Arctic regions to the civilized world. He did not pretend to have visited them, but in or about 330 B.C. he set out from Marseilles and journeyed north. During this voyage, which must have lasted for several years, he visited Britain, and then, proceeding to the most northerly point of the British Isles, he heard of an Arctic land called Thule, which at one time of the year enjoyed perpetual day, and at another had to endure perpetual night. With a leap over a few hundred years we come to Ptolemy, whose influence on geography was almost paramount from the second century to comparatively modern times. No one is more dangerous than a bad cartographer, or more valuable than a good one; but although Ptolemy made many mistakes, he also did such splendid work that it is quite easy to forget them. To him we owe the names of latitude and longitude, and it has been well said of him that he held the extraordinary "distinction of being the greatest authority on astronomy and geography for over fifteen hundred years." Ptolemy's work may have required to be corrected and amplified, but, at least, he gave the world something which was worthy of correction. In the eighth and ninth centuries the Norsemen became terrors in Europe. "Harold of the fair hair" reigned from 860 to 930 A.D., and these seventy years formed a period of great adventure. During Harold's reign the Norsemen colonized Iceland, and in 983 Erik the Red founded a colony in Greenland, which flourished until the Norwegians ceased to take an interest in it. Not until the fifteenth century did English seamen begin to turn their attention to the North. They were more or less forced to do so. Portugal and Spain were all-powerful in the East and West, and so England began earnestly to think of discovering a way to Cathay and the Spice Islands by a northern route. But if we were a little slow in beginning to pay attention to the Arctic regions, we have every cause to be satisfied with our work after we had once begun it. The fifteenth century saw considerable activity as regards Scandinavia, but it was not until 1505 that a charter was granted to the Company of Merchant Adventurers, and from that year we can date our real interest in Arctic discovery. It is well, perhaps, to bear in mind, while thinking of Polar exploration, that there is a marked difference between the two Polar regions. The Arctic is an ocean surrounded by continental lands; the Antarctic is a continental land surrounded by oceans.