When the Macedonians had covered more than half the distance between the shore and the wall, the Ph[oe]nicians began to resist their advance. The catapults were brought into play. These were great bows of tough wood, set in a solid framework. The strings of twisted gut were drawn back by a windlass, and huge arrows, made of iron and weighing two or three hundred pounds, were fitted to the groove prepared for them. The string was released by drawing a trigger as in a cross-bow, and the missile sped to the mark.
The catapults were reënforced by the ballistæ. In a frame of heavy beams an arm was set, with a great spoon at one end, while the other was held firmly in twisted cords. By means of a rope wound about a roller the arm was drawn back, and a stone or a ball of metal was placed in the spoon. Suddenly freed, the arm flew up until it was halted by a cross-beam of the framework, when the missile left it and hurtled through the air toward the mole.
While darts and stones were showered upon the causeway from the walls, vessels attacked it from both harbors, filled with archers and slingers, who drove the workmen back. Tyre was jubilant. Alexander, she thought, must now surely abandon his foolish enterprise.
Work on the causeway was indeed halted for a time, but only long enough to permit the Macedonians to contrive means of defence. Two great towers were built and pushed out to the end of the mole. These were tall enough to dominate the wall. They were provided with catapults and ballistæ, with which to answer and silence those of the Tyrians, and were manned by soldiers, who from their height were able to reach the decks of the triremes that were sent to annoy them. For further protection, palisades of timber and movable breastworks were constructed on the mole, and pushed forward as it advanced.
Work was resumed, and the long causeway crept nearer and nearer to the city. By order of the council, under cover of night, sponge and pearl divers were sent to the mole in small vessels. With cords in their hands they plunged into the water and fastened them to the foundation stones of the mole, which the crews on board the boats pulled away.
But in spite of all these devices, the mole continued to lengthen.