About the time that Alexander was making his way eastward through Persia, Pytheas was leaving the Greek colony of Marseilles for the west and north. The Phœnicians, with their headquarters at Carthage, had complete command of the mineral trade of Spain—the Mexico of the ancient world. They knew where to find the gold and silver from the rivers—indeed, they said that the coast, from the Tagus to the Pyrenees, was "stuffed with mines of gold and silver and tin." The Greeks were now determined to see for themselves—the men of Carthage should no longer have it all their own way. Where were these tin islands, kept so secret by the master-mariners of the ancient world?

A committee of merchants met at Marseilles and engaged the services of Pytheas, a great mathematician, and one who made a study of the effect of the moon on the tides. All sorts of vague rumours had reached the ears of Pytheas about the northern regions he was about to visit. He would discover the homes of the tin and amber merchants, he would find the people who lived "at the back of the north wind," he would reach a land of perpetual sunshine, where swans sang like nightingales and life was one unending banquet.

So Pytheas, the mathematician of Marseilles, started off on his northern trip. Unfortunately, his diary and book called The Circuit of the Earth  have perished, and our story of geographical discovery is the poorer. But these facts have survived.

The ships first touched at Cadiz, the "Tyre of the West," a famous port in those days, where Phœnician merchants lived, "careless and secure" and rich. This was the limit of Greek geographical knowledge; here were the Pillars of Hercules, beyond which all was dim and mysterious and interesting. Five days' sail, that is to say, some three hundred miles along the coast of Spain, brought Pytheas to Cape St. Vincent.

He thought he was navigating the swift ocean river flowing around the world. He was, therefore, surprised to find as he rounded the Cape that the current had ceased, or, in his own words, the "ebb came to an end." Three days more and they were at the mouth of the Tagus. Near this part of the coast lay the Tin Islands, according to Greek ideas, though even to-day their exact locality is uncertain. Pytheas must have heard the old tradition that the Cassiterides were ten in number and lay near each other in the ocean, that they were inhabited by people who wore black cloaks and long tunics reaching to the feet, that they walked with long staves and subsisted by their cattle. They led a wandering life; they bartered hides, tin, and lead with the merchants in exchange for pottery, salt, and implements of bronze.

That these islands had already been visited by Himilco the Carthaginian seems fairly certain. He had started from Cadiz for the north when Hanno started for the south. From the Tin Islands his fleet had ventured forth into the open sea. Thick fogs had hidden the sun and the ships were driven south before a north wind till they reached, though they did not know it, the Sargasso Sea, famous for its vast plains of seaweed, through which it was difficult to push the ships.

"Sea animals," he tells us, "crept upon the tangled weed." It has been thought that with a little good fortune Himilco might have discovered America two thousand years before the birth of Columbus. But Himilco returned home by the Azores or Fortunate Islands, as they were called.

Leaving the Tin Islands, Pytheas voyaged on to Cape Finisterre, landing on the island of Ushant, where he found a temple served by women priests who kept up a perpetual fire in honour of their god. Thence Pytheas sailed prosperously on up the English Channel till he struck the coast of Kent. Britain, he announced, was several days' journey from Ushant, and about one hundred and seventy miles to the north. He sailed round part of the coast, making notes of distances, but these are curiously exaggerated. This was not unnatural, for the only method of determining distance was roughly based on the number of miles that a ship could go in an hour along the shore. Measuring in this primitive fashion, Pytheas assures us that Britain is a continent of enormous size, and that he has discovered a "new world." It is, he says, three cornered in shape, something like the head of a battleaxe. The south side, lying opposite the coast of France, is eight hundred and thirty-five miles in length, the eastern coast is sixteen hundred and sixty-five miles, the western two thousand two hundred and twenty-two—indeed, the whole country was thought to be over four thousand miles in circumference. These calculations must have been very upsetting to the old geographers of that age, because up to this time they had decided that the whole world was only three thousand four hundred miles long and six thousand eight hundred broad.

He tells us that he made journeys into the interior of Britain, that the inhabitants drink mead, and that there is an abundance of wheat in the fields.

"The natives," he says, "collect the sheaves in great barns and thrash out the corn there, because they have so little sunshine that an open thrashing-place would be of little use in that land of clouds and rain." He seems to have voyaged north as far as the Shetland Islands, but he never saw Ireland.

Having returned from the north of the Thames, Pytheas crossed the North Sea to the mouth of the Rhine, a passage which took about two and a half days. He gives a pitiable account of the people living on the Dutch coast and their perpetual struggle with the sea. The natives had not learnt the art of making dykes and embankments. A high tide with a wind setting toward the shore would sweep over the low-lying country and swamp their homes. A mounted horseman could barely gallop from the rush and force of these strong North Sea tides.

But the Greek geographers would not believe this; they only knew the tideless Mediterranean, and they thought Pytheas was lying when he told of the fierce northern sea. Pytheas sailed past the mouth of the Elbe, noting the amber cast upon the shore by the high spring tides. But all these interesting discoveries paled before the famous land of Thule, six days' voyage north of Britain, in the neighbourhood of the frozen ocean. Grand excitement reigned among geographers when they heard of Thule, and a very sea of romance rose up around the name. Had Pytheas indeed found the end of the world? Was it an island? Was it mainland? In the childhood of the world, when so little was known and so much imagined, men's minds caught at the name of Thule— Ultima Thule—far-away Thule, and weaved round it many and beautiful legends. But to-day we ask: Was it Iceland? Was it Lapland? Was it one of the Shetland Isles?

"Pytheas said that the farthest parts of the world are those which lie about Thule, the northernmost of the Britannic Isles, but he never said whether Thule was an island or whether the world was habitable by man as far as that point. I should think myself"—the speaker is Strabo, a famous Greek traveller who wrote seventeen books of geography—"I should think myself that the northern limit of habitude lies much farther to the south, for the writers of our age say nothing of any place beyond Ireland, which is situate in front of the northern parts of Britain." Pytheas said that Thule was six days' sail north of Britain. "But who in his senses would believe this?" cries Strabo again. "For Pytheas, who described Thule, has been shown to be the falsest of men. A traveller, starting from the middle of Britain and going five hundred miles to the north, would come to a country somewhere about Ireland, where living would be barely possible."

The first account of the Arctic regions likewise reads like pure romance to the ignorant and untravelled. "After one day's journey to the north of Thule," says Pytheas, "men come to a sluggish sea, where there is no separation of sea, land, and air, but a mixture of these elements like the substance of jelly-fish, through which one can neither walk nor sail." Here the nights were very short, sometimes only two hours, after which the sun rose again. This, in fact, was the "Sleeping Palace of the Sun."

With all this wealth of discovery, Pytheas returned home by the Bay of Biscay to the mouth of the Gironde; thence sailed up the Garonne, and from the modern town of Bordeaux he reached Marseilles by an overland journey.