“Don’t break ’em all,” called Joe. “I want to be in on this.”

Frank continued up the ladder. Occasionally, when he came to a place where a rung had broken off, he was obliged to haul himself upward by main force, but finally he neared the top. The ladder ran up along the side of the tank to the very top of the great, vat-like receptacle, and there it led to a trapdoor.

The Hardy boys did not look down. They were high above the ground now, and the old water tower was swaying alarmingly. They began to realize their peril, for the tower was old and liable to topple over with them. But the thought did not serve to restrain them, and at last Frank scrambled over the last rung and found himself on the upper surface of the tower. He turned around and helped Joe over.