scampering
back.

"Oh, here's one side, sir," said Hardock, taking a few steps to his
left, and once more holding up his light against a rugged mass of
granite veined with white quartz, and glistening as if studded with
gems.

"How beautiful!" cried Joe.

"Let's throw a light on the subject," said Gwyn, merrily. "Open your
lanthorn, Joe;" and as this was done he lit the end of a piece of
magnesium ribbon, which burned with a brilliant white light and sent up
a cloud of white fumes to rise slowly above their heads.

The light brightened the place for a minute, and in that brief interval
the two friends feasted their eyes upon the crystal-hung roof and walls
of the lovely grotto, whose sides rose to about forty feet above their
heads, and then joined in a correct curve that was nearly as regular as
if it had been the work of some human architect. A hundred feet away
the roof sank till it was only two or three yards above the irregular
floor, and the place narrowed in proportion, while where they stood the
walls were some fifty feet apart.

Then the ribbon gave one flash, and was dropped on the floor, to be
succeeded by a black darkness, out of which the lanthorns shed what
seemed to be three dim sparks.

"What do you think of it, gen'lemen?" said Hardock, from out of the
black darkness.

"Grand! Lovely! Beautiful! I never saw anything like it," cried Gwyn.

"Why, it must be the most valuable part of the mine," cried Joe.

Hardock chuckled.

"It's just the part, sir, as is worth nothing except for show," he said.
"It's very pretty, but there isn't an ounce o' tin to a ton o' working
here, sir, and--"

His words were checked by a faintly-heard muffled roar, which was
followed by a puff of moist air and the customary whispering sound of
echoes; but before they had died away Grip set up his ears, passed right
away into the darkness, and barked with all his might.

"Quiet, sir!" cried Gwyn; but the dog barked the louder.

"Kick him, Ydoll; it's deafening," cried Joe.

"Didn't that shot sound rather rum to you?" said Hardock.

"Oh, I don't know," replied Gwyn, who was slow to take alarm. "Sounded
like a shot and the echoes."

"Nay; that's what it didn't sound like," said Hardock, scratching his
head. "It was sharper and shorter like, and we didn't ought to hear it
like that all this distance away."

"Isn't the roof of the mine fallen in, is it?" said Gwyn, maliciously,
as he watched the effect of