His fleet, counting vessels of all kinds, probably now numbered not less than three hundred and fifty ships. By their aid Mahomet hoped to gain possession of the harbour by destroying or forcing the boom. Accordingly, Baltoglu sailed down from the Double Columns, towards the ships stationed for its defence, and endeavoured to force an entry. The Turkish crews came on with the battle-cry of ‘Allah, Allah!’ and when within gun- and arrow-shot of their enemies closed bravely for the attack. The cuirassiers tried to burn the vessels at the boom with torches; others discharged arrows bearing burning cotton, while others again endeavoured to cut the cables of some of the ships so that they might be free to destroy the boom. In other parts they sought to grapple with the defending vessels and if possible to capture them. Both sides fought fiercely, but the Greeks and Italians, under the leadership of the Grand Duke Notaras, had provided against all the Turkish means of attack. The defending ships were higher out of the water than those of the Turks, and this gave them an advantage in throwing stones and discharging darts and javelins. Stones tied to ropes had been taken aloft on the yards and bowsprits, and the dropping of these into vessels alongside caused great damage. Barrels and other vessels full of water were at hand to extinguish fire. After a short but fierce fight the assailants judged that for the present at least the attempt to capture the boom and thus obtain an entrance into the harbour was hopeless, and amid taunts and shouts of joy from the Christians withdrew to the Double Columns. On April 20 we come to an incident at once interesting and suggestive. [Sidenote: Attempt to capture ships bringing aid.] In the midst of a story which is necessarily depressing from the consciousness that it is that of a lost cause, one incident is related by all Christian contemporary writers, whether eye-witnesses or not, with satisfaction or delight. This is the incident of a naval battle under the walls of the city itself. Spectators and writers dependent on the testimony of others who had seen the fight differ among themselves as to details but agree as to the main facts.