The brave commander, Martin Vargas, was offered the alternative of embracing Mohammedanism and a Mohammedan wife or execution. He chose the latter, and was beaten to death with sticks, his body was dragged through the streets, cut into pieces, and thrown into the sea. So did the corsair treat a gallant foe. It was then that Kheir-ed-Din conceived the project of uniting the island and the city, with the double object of preventing any repetition of the Spanish occupation and of providing a harbour for his fleet. Thirty thousand Christian slaves supplied him with labour, and materials lay near to hand. The ruins of the old Roman city of Rusgania strewed the shore at Cape Matifou; and countless blocks of Roman hewn stone and marble lie buried beneath the floor of the mole. The work, a very big work for the period, was finished in three years, and henceforth for nearly three centuries the corsair fleets lay within, safe from the storms of the Mediterranean and the attacks of their enemies. Kheir-ed-Din’s son mounted batteries on the Penon, and built the lighthouse tower in 1544. It is of octagonal shape, nearly 120 feet high, and visible for a distance of fifteen miles. A band of gleaming tiles below the summit happily relieves the monotony of its elevation. The present great harbour, covering 222 acres, was commenced by the French in 1836. It was formed by continuing the line of Kheir-ed-Din’s mole to the south-east, and building another of irregular form from a point to the south of the city. In these works blocks of concrete were used for the first time in such operations,—an experiment which has had important results. In the making of this great harbour, as in so many other constructive matters, the French have risen to the level of their opportunities. Their genius in such large matters is unquestioned; and if anyone doubts their pre-eminence in minor arts, let him compare their coinage and their postage stamps with those of any other nation.