feet in diameter.

"That's where the wind comes from," Mr. Stanlock decided. "It's the
mouth of the old mine we used to hear about years ago. But where's the
other opening? Funny nobody knows about that. This end has been
covered up with that old heavy door and concealed with a layer of
earth. When our men moved the pile of lumber, they observed that the
earth had been disturbed recently and shoveled it away and found this
hole."

Mr. Stanlock directed the rays of light into the hole and discovered a
flight of steps cut in the hard clay.

"The lieutenant and his men are down in there," he concluded. "I think
I'll follow them."

He descended cautiously into the hole. Half a dozen irregularly formed
steps brought him to a slope leading downward on an inclined plane of
six or seven degrees. He was astonished at the degree of preservation
of the walls, ceiling, and supports, considering the years that had
elapsed since the mine was last worked. The passage continued as a
downward slope for about fifty yards and then became almost level for
a like distance. Only in two places had the walls or ceiling fallen in
to any considerable extent, and in neither of those places was the
obstruction so great as to constitute an impassable barrier.

As he proceeded, Mr. Stanlock peered ahead anxiously, in the hope that
he would discover the lights of Lieutenant Larkin and his companions.
But he walked nearly 100 yards through an irregular and
characteristically jagged passage before he caught sight of anything