"Have you discovered anything?" asked Dick.
"Here, boys," he said, "you will see there is a crack in the wall. That may be the cause of the hollow sound I fancied it gave. But, look!" he added, holding the match high above his head, "see how the crack widens as it rises toward the ceiling. By Jove, boys! it's almost wide enough up there for a cat to get through."
Then the match burned too short to be held longer, and he dropped it. Several moments he stood in silence, paying no heed to the words of Dick or Brad. His mind was busy. Finally he said:
"Get up here, boys, both of you. Face this wall and stand close together. I want to climb on your shoulders. I am going to examine that crack. It may be our only hope of salvation."
They followed instructions, and Merry mounted to their shoulders, on which he stood. In this manner he was high enough to reach some distance into the crack in the wall. He found nothing but crumbling bits of cement and stone, which was a disappointment to him.
"Keep your heads down," he said. "I am going to see if I can loosen some of this outer coat of cement here. It may rattle down about your ears."
He pulled away at the cement, cleaving it off easily and exposing the fact that the wall was somewhat shabbily built above a distance of eight feet from the floor. An earthquake or convulsion of nature, or whatever had caused the crack in the wall, had seriously affected it, and it seemed very shaky and unstable indeed.
Several times he shifted about on the boys' shoulders to give them rest, as his heavy boots were rather painful after remaining in one position a few moments. They were eager to know what progress he was making.
"I can't tell what it amounts to, boys," he declared. "This crack may lead nowhere, even if I can make an opening large enough to enter."
At length he was compelled to descend in order to give them a chance to rest. Three times he mounted on their shoulders and worked at the cement and stones until the skin of his fingers was torn and his hands bleeding. He was making progress, nevertheless, and it seemed more and more apparent that, if given time enough, an opening might be made there at that height in the wall. In his final efforts he loosened a mass of the stuff, that suddenly gave way and went rattling and rumbling down into the wall somewhere. To his intense satisfaction, this left a hole large enough for a human being to creep into.