Without a word the boys slipped away. Mr. Hardy then placed on a round shelf nailed to the flagstaff, at about eight feet from the ground, a blue-light, fitting into a socket on the shelf. The shelf was made just so large that it threw a shadow over the top of the tower, so that those standing there were in comparative darkness, while everything around was in bright light. There, with a match in his hand to light the blue-light, he awaited the signal.

It was a long time coming--so long that the pause grew painful, and every one in the house longed for the bursting of the coming storm. At last it came. A wild, long, savage yell from hundreds of throats rose on the still night air, and, confident as they were in their position, there was not one of the garrison but felt his blood grow cold at the appalling ferocity of the cry. Simultaneously there was a tremendous rush at the doors and windows, which tried the strength of frame and bar. Then, as they stood firm, came a rain of blows with hatchet and tomahawk.