The great cannon of Mahomet could only be fired seven times in one day, but the weight and repetition of the shots made some impression on the walls. The Turks rushed to the edge of the ditch, attempted to fill the enormous chasm and to build a road to the assault. In the attack, as well as in the defence, ancient and modern artillery was employed. Cannon and mechanical engines, the bullet and the battering-ram, gunpowder and Greek fire, were engaged on both sides. Christendom watched the struggle with coldness and apathy. Four ships, which successfully forced an entrance into the harbour, were the limit of their assistance. None the less, Mahomet meditated a retreat. Unless the city could be attacked from the harbour, its reduction appeared to be hopeless. In this perplexity the genius of Mahomet executed a plan of a bold and marvellous cast. He transported his fleet over land for ten miles. In the course of one night four-score light galleys and brigantines painfully climbed the hill, steered over the plain, and were launched from the declivity into the shallow waters of the harbour, far above the molestation of the deeper vessels of the Greeks. A bridge, or mole, hastily built, formed a base for one of his largest cannon. The galleys, with troops and scaling ladders, approached the most accessible side of the walls, and, after a siege of forty days, the diminutive garrison, exhausted by a double attack, could hope no longer to avert the fate of the capital. On Monday, May 28, preparations were made for the final assault. Mahomet had inspired his soldiers with the hope of rewards in this world and the next. His camp re-echoed with the shouts of "God is God; there is but one God, and Mahomet is the apostle of God"; and the sea and land, from Galata to the Seven Towers, were illuminated with the blaze of the Moslem fires. Far different was the state of the Christians. On that last night of the Roman Empire, Constantine Palæologus, in his palace, addressed the noblest of the Greeks and the bravest of the allies on the duties and dangers that lay before them. It was the funeral oration of the Roman Empire. That same night the emperor and some faithful companions entered the Dome of St. Sofia, which, within a few hours, was to be converted into a mosque, and devoutly received, with tears and prayers, the sacrament of the Holy Communion. He reposed some moments in the palace, which resounded with cries and lamentations, solicited the pardon of all whom he might have injured, and mounted on horseback to visit the guards and explore the motions of the enemy. The distress and fall of the last Constantine are more glorious than the long prosperity of the Byzantine Cæsars.