Bertie moved along to let the others look at the edge. He was keeping his finger on the joint, and they had scarcely come up when he said, "The other end of the stone's sunk in about as much as this end projects."
"Something certainly occurred to shift this stone a little," Harry said, examining it carefully. "It is curious. If others had been displaced, one would have put it down to the shock of an earthquake—a common enough occurrence here—but both above and below it the stones are level with the others, and nowhere about the house have we seen such another displacement. Look! there is a heap of rubbish along the foot of the wall here. Stir it up, Dias, and let us see what it is."
"It is sand and small stones, and some chips that look like chips of rock."
"Yes, these bits look, as you say, as if they had been chipped off a rock, not like water-worn stones. Though how they got here, where everywhere else things are perfectly tidy, I cannot say. However, we can think that over afterwards. Now for the stone! Let us all put our weight against this projecting end. I don't in the least expect that we can move it, but at any rate we can try."
They all pushed together.
"I think it moved a little," Harry said, and looked at the edge.
"Yes, it is not above half as far out now as it was."
"That is curious, for if it is as thick as we took it to be, it would weigh at least a couple of tons. We won't try to push it in any farther. I am sorry we pushed it at all. Now, give me that heavy sledge, José, possibly there may be a hollow sound to it. I will hit at the other end, for I don't want this to go in any farther."
He went to the stone beyond it first and struck two or three blows with all his strength. Then he did the same with the stone that they were examining.
"I don't think it gives such a dead sound," he said.