Pytheas ventured still further north, and went beyond the Orcades Islands to the furthest point of Scotland, and he must have reached a very high latitude, for during the summer the night only lasted two hours. After six days further sailing, he came to lands which he calls Thule, probably the Jutland or Norway of the present day, beyond which he could not pass, for he says, "there was neither land, sea, nor air there." He retraced his course, and changing it slightly, he came to the mouth of the Rhine, to the country of the Ostians, and, further inland, to Germany. Thence he visited the mouth of the Tanais, that is supposed to be the Elbe or the Oder, and he retuned to Marseilles, just a year after leaving his native town. Pytheas, besides being such a brave sailor, was a remarkably scientific man: he was the first to discover the influence that the moon exercises on the tides, and to notice that the polar star is not situated at the exact spot at which the axis of the globe is supposed to be. Some years after the time of Pytheas, about B.C. 326 a Greek traveller made his name famous. This was Nearchus, a native of Crete, one of Alexander's admirals, and he was charged to visit all the coast of Asia from the mouth of the Indus to that of the Euphrates. When Alexander first resolved that this expedition should take place, which had for its object the opening up of a communication between India and Egypt, he was at the upper part of the Indus. He furnished Nearchus with a fleet of thirty-three galleys, of some vessels with two decks, and a great number of transport ships, and 2000 men. Nearchus came down the Indus in about four months, escorted on either bank of the river by Alexander's armies, and after spending seven months in exploring the Delta, he set sail and followed the west line of what we call Beloochistan in the present day. He put to sea on the second of October, a month before the winter storms had taken a direction that was favourable to his purpose, so that the commencement of his voyage was disastrous, and in forty days he had scarcely made eighty miles in a westerly direction. He touched first at Stura and at Corestis, which do not seem to answer to any of the now-existing villages on the coast; then at the Island of Crocala, which forms the bay of Caranthia. Beaten back by contrary winds, after doubling the cape of Monze, the fleet took refuge in a natural harbour that its commander thought that he could fortify as a defence against the attacks of the barbarous natives, who, even at the present day, keep up their character as pirates.