"There are sure to be some boats somewhere on this lake," Jack said, "and we might get hold of one and go across to Alexandria some night, and reconnoitre. If we find there are no sailors or troops there, we can take to our boat and pull back again. I think it would be better to do that than to try to work round by the sea-shore, for I believe they have fortifications running across from the sea to the lake, so as to prevent the place from being attacked by a force landing beyond the forts."