The evidence presented to-day by the ruined condition of the walls in these places corroborates the statements made by contemporaries, that these were the principal places bombarded. Mahomet was already able to claim with some justice that he had opened three entrances for his army into the city.[358] Several of the towers between the Adrianople Gate and Caligaria had been destroyed. The Anatolian division had greatly weakened those in the neighbourhood of the Third Military Gate. But the most extensive destruction had been wrought by the Janissaries with the aid of the great cannon of Urban. While in each of the three places mentioned the Outer Wall is even now in an exceptionally dilapidated condition, the ruins in the valley of the Lycus show that this was the place where the cannon had been steadily pounding day and night. Along almost the whole length of the foss, extending for upwards of three miles, its side walls and a great portion of the breastwork still remain, mostly, to all appearances, as solid as when they were new. But in the lower part of the Lycus valley hardly more than a trace of either is to be distinguished. The breastwork had been entirely destroyed and had helped to raise the foss to the level of the adjoining ground. A large portion of the Outer Wall and some of its towers had been broken down. The ruins of the Bactatinean tower had helped to fill the ditch; two towers of the great Inner Wall had fallen. A breach of twelve hundred feet long according to Tetaldi had been made opposite the place where Mahomet had his tent.[359] Here, where the largest cannon was placed, the struggles had been keenest. Here was the station of John Justiniani with his two thousand men, among whom were his own four hundred Genoese cuirassiers with their arms glittering in the sun to the delight, says Leonard, of their Greek fellow fighters. While the cannon had greatly damaged the walls in the other two places mentioned, here, says Critobulus, they had entirely destroyed them. There was a wall no longer, nor did there in this part exist any longer a ditch, for it had been filled up by the Turkish troops.[360] Hence it was that in this part Justiniani and those under him had been constantly occupied in repairs. Day after day the diarists recount that the principal occupation of the besieged was to repair during the night the part of the walls destroyed during the day by the cannon. Without experience of the power of great guns even in their then early stage of development, the besieged tried to lessen the force of the balls by suspending from the summit of the walls a sheathing of bales of wool. This and other expedients had failed. [Sidenote: Construction of stockade.]