The man made no reply. To him and his comrades the escape of the British ships was a mystery. That they were made of iron they understood, but had no idea of the enormous thickness of their sides; and could not even imagine that ships could be built sufficiently strong to keep out the missiles discharged by the immense cannons in the forts. That not even a mast should have been knocked away seemed to them almost miraculous. In point of fact the ships had been struck but once or twice with the shells from these massive cannon. The Egyptian gunners were unaccustomed to the use of the huge pieces, and had consequently aimed too high, and the shell had passed either between the masts or far overhead.