It was as Frank had said.
Buried in the earth which composed the cellar floor a flat stone of a grayish color was discovered, above which all now stood.
"The spades, Barney and Sandy!" cried Frank, seizing the pick-ax himself. "Hold the light, Garibaldi, that we may see what we are about. Make what noise you like, boys, there's no one to hear us—this house has been deserted for years."
He struck the ground with the pick-ax as he spoke, the sound echoing upon the rafters of the floor above.
The earth once loosened, Barney and Sandy made short work of it with their spades.
It was of a light and sandy character, and yielded so readily to their efforts that Frank, finding the pick-ax useless, soon threw it to one side, and taking the spade from the hands of Sandy, joined Barney in the hole, now rapidly deepening.
Both boys had removed their coats, and were working with a will.
Around them the little mound of earth thrown out by their spades steadily grew, until a depth of four feet or more was reached.
And yet, they had found nothing. Nor was there any appearance that the earth had been ever disturbed.
"By thunder, but this is tough work!" growled Barney, straightening himself up. "How much further do you think we've got to go?"