one, up and down which huge weights, which depended from
massive chains and passed over great rollers, had formerly been used to
glide.

Ben shook his head as he put his hand upon one of the weights, which
were formed of so many discs of cast lead, through the centre of which
the great chain passed, a solid bar of iron being driven through a link
below to keep them from sliding off.

The weights hung about breast-high; and at the slight pressure of the
man's hand began to swing to and fro in the stone place open to the
chamber, but closed below where they ran down in the wall at the sides
of the gate-way.

"Well, these must have been worked by hand, Ben," said Roy. "Men must
have stood here and run them down. Two of you go to the other side, and
all press down together, but stand ready to jump back in case anything
breaks. I don't see how you can be hurt if you do."

"No, sir; no one can't be hurt, for the weights will only go down these
holes with a bang."

"Try, then. Now, all together--pull!"

The men tugged and strained, but there was no sign of yielding, and Ben
shook his head.

"Rollers must be rusted, sir, and stick."

But upon his climbing up to examine them, it proved that these had not
been made to turn, only for the chains to slide over them, as the
grooves worn in the iron showed.

"Nothing to stop 'em here, sir," said the man.

"Then it must be set fast at the end of the bridge," said Roy; and,
descending with the men, they crossed the moat and found the bridge
completely wedged and fixed in the opening of stone which embraced the
end.

Picks and crowbars were fetched, the stones and sand scraped out, and
when the place was cleared they reascended to the furnace-chamber, when,
upon another trial being made, it was found that the weights so
accurately balanced the bridge that with very little exertion the chains
came screeching and groaning over the iron rollers, and the men gave a
cheer as the end rose up and up till it was drawn very nearly up to the
face of the tower.

Ben rubbed his ear and grinned with satisfaction.

"Come, sir," he said, "we can make ourselves pretty safe that way; but
I'm afraid the moat's so filled up that a man can wade across."

"That he can't," cried one of the gardeners. "I've plumbed it all over,
and there aren't a place less nor seven or eight feet deep, without
counting the mud."

"Then you've been fishing!" thought Roy, but he did not say so, only
ga