“Nor from below,” said Mr. Merryweather, striking his stick upon the flags which lined the floor. “Why, dear me, it sounds quite hollow!” he remarked, looking up in surprise.

“I must really ask you to be a little more quiet!” said Holmes severely. “You have already imperilled the whole success of our expedition. Might I beg that you would have the goodness to sit down upon one of those boxes, and not to interfere?”

The solemn Mr. Merryweather perched himself upon a crate, with a very injured expression upon his face, while Holmes fell upon his knees upon the floor and, with the lantern and a magnifying lens, began to examine minutely the cracks between the stones. A few seconds sufficed to satisfy him, for he sprang to his feet again and put his glass in his pocket.