After examining carefully all the circumstances of the case, Alexander conceived the very bold plan of building a broad causeway from the main-land to the island on which the city was founded, out of the ruins of old Tyre, and then marching his army over upon it to the walls of the city, where he could then plant his engines and make a breach. This would seem to be a very desperate undertaking. It is true the stones remaining on the site of the old city afforded sufficient materials for the construction of the pier, but then the work must go on against a tremendous opposition, both from the walls of the city itself and from the Tyrian ships in the harbor. It would seem to be almost impossible to protect the men from these attacks so as to allow the operations to proceed at all, and the difficulty and danger must increase very rapidly as the work should approach the walls of the city. But, notwithstanding these objections, Alexander determined to proceed. Tyre must be taken, and this was obviously the only possible mode of taking it.