Two important questions occupied the mind of Xerxes. How was he to get his vast army on European soil, and how escape those dangers from storm which had wrecked his father's fleet? He might cross the sea in ships, as Datis had done,--and be like him defeated. Xerxes thought it safest to keep on solid land, and decided to build a bridge of boats across the Hellespont, that ocean river now known as the Dardanelles, the first of the two straits which connect the Mediterranean with the Black Sea. As for the other trouble, that of storms at sea, he remembered the great gale which had wrecked the fleet of Mardonius off the stormy cape of Mount Athos, and determined to avoid this danger. A narrow neck of land connects Mount Athos with the mainland. Xerxes ordered that a ship-canal should be cut through this isthmus, wide and deep enough to allow two triremes--war-ships with three ranks of oars--to sail abreast. This work was done by the Phoenicians, the ablest engineers at that time in the world. A canal was made through which his whole fleet could sail, and thus the stormy winds and waves which hovered about Mount Athos be avoided. This work was successfully done, but not so the bridge of boats. Hardly had the latter been completed, when there came so violent a storm that the cables were snapped like pack-thread and the bridge swept away. With the weakness of a man of small mind, on hearing of this disaster Xerxes burst into a fit of insane rage. He ordered that the heads of the chief engineers should be cut off, but this was far from satisfying his anger. The elements had risen against his might, and the elements themselves must be punished. The Hellespont should be scourged for its temerity, and three hundred lashes were actually given the water, while a set of fetters were cast into its depths. It is further said that the water was branded with hot irons, but it is hard to believe that even Xerxes was such a fool as this would make him. The rebellious water thus punished, Xerxes regained his wits, and ordered that the bridge should be rebuilt more strongly than before. Huge cables were made, some of flax, some of papyrus fibre, to anchor the ships in the channel and to bind them to the shore. Two bridges were constructed, composed of large ships laid side by side in the water, while over each of them stretched six great cables, to moor them to the land and to support the wooden causeway. In one of these bridges no less than three hundred and sixty ships were employed. And now, everything being ready, the mighty army began its march. It presented a grand spectacle as it made its way from Sardis to the sea. First of all came the baggage, borne on thousands of camels and other beasts of burden. Then came one-half the infantry. The other half marched in the rear, while between them were Xerxes and his great body-guard, which is thus described by the Greek historian: