Alexander began the siege of Tyre without any fleet; the Sidonian and Aradian ships not having yet come. It was his first task to construct a solid mole two hundred feet broad, reaching across the half mile channel between the mainland and the islet. He pressed into his service laboring hands by thousands from the neighborhood; he had stones in abundance from Palætyrus, and wood from the forests in Lebanon. But the work, though prosecuted with ardor and perseverance, under pressing instigations from Alexander, was tedious and toilsome, even near the mainland, where the Tyrians could do little to impede it; and became far more tedious as it advanced into the sea, so as to be exposed to their obstruction, as well as to damage from winds and waves. The Tyrian triremes and small boats perpetually annoyed the workmen, and destroyed parts of the work, in spite of all the protection devised by the Macedonians, who planted two towers in front of their advancing mole, and discharged projectiles from engines provided for the purpose. At length, by unremitting efforts, the mole was pushed forward until it came nearly across the channel to the city wall; when suddenly, on a day of strong wind, the Tyrians sent forth a fireship loaded with combustibles, which they drove against the front of the mole and set fire to the two towers. At the same time, the full naval force of the city, ships and little boats, was sent forth to land men at once on all parts of the mole. So successful was this attack, that all the Macedonian engines were burnt,—the outer wood-work which kept the mole together was torn up in many places,—and a large part of the structure came to pieces.[319] [319] Arrian, ii. 18, 19; Diodor. xvii. 42; Curtius, iv. 3, 6, 7.