"It certainly looks as if the stone had been struck with something heavy," Harry said. "I should think, by the appearance, some very heavy piece of rock must have been dropped upon it."
"Yes, señor, very heavy rock—so heavy that there must have been many men to lift it."
"It must have been heavy indeed to break up this slab."
"Perhaps it is not so thick as the others," Dias suggested.
"I don't like it, Dias. Well, let us set to work. We will try the wedges there. They were no use against the solid stone, but they might move these pieces. Put one of the borers just at the place from which these cracks start—at least, I suppose they are cracks—and let us drive it in for an inch. You hold it, José. Don't turn it, we want it to go in just in a line with this crack. I know we cannot drive it in far, but at least we may make it go deep enough to give a wedge a hold in it."
Five such small holes were made in a crack that seemed to form a rough circle, then the wedges were put in, and they began to work with sledges. In ten minutes Harry, examining the place carefully, said: "The bit of stone is breaking up. There are lines running across it from the wedges. Give me the heaviest sledge." He swung it round his head and brought it down half a dozen times in the centre of the wedges. The cracks opened so far that he could see them without stooping.
"Now we will try with the crowbars," he said.
In ten minutes a fragment of the stone was got up; then they hammered on the wedges again, and a piece of rock, which was roughly seven or eight inches in diameter, broke completely off.
"It is only about two and a half inches thick," Harry said as he drew one of the fragments out. And, holding the candle to the hole, he went on: "And there is another slab underneath. That settles it. We are at the top of one of these vaults. The question is, is it empty? I am afraid it is. This stone has evidently been broken up and fitted in again with wonderful care."
"Why should it be fitted in carefully if they emptied the chamber?"