“ Mr. Stone,” he said respectfully, “I am sure you know what you’re talking about, but will you tell me how a man could get up through that hole? It doesn’t seem to me that a small-sized boy could squeeze through.”

Fleming Stone took a silver-cased tape-measure from his pocket, and handed it to Rob without a word.

Eagerly stooping on the hearth, Rob measured the oval opening in the iron plate. Although the rectangular plate was several inches larger each way, the oval opening measured exactly nine and one-half inches by thirteen and one-half inches.

“Who could get through that?” he inquired, as he announced the figures. “I’m sure I couldn’t.”

“And Schuyler Carleton is a larger man than you are,” observed Mr. Fairbanks.