would be
impossible for a man to spring over. The boards they carried down as
they descended, when they found themselves in another storey, the whole
of which was occupied by one large room without doors, the reason, of
course, why it had not been made their prison.

Their candle had now nearly burned out. Having hung their shoes round
their necks, they were able to step softly. Hunting about, they
discovered an empty space under the stairs, in which they stowed the
pieces of wood.

"Perhaps we might get down by the stairs," whispered Jack.

"The chances are that we should find a door to stop us at the bottom,"
returned Bill. "We must try to get down the outside. The walls are so
full of holes that we might manage it, and I am ready to go first and
try."

The question was, on which side should they attempt to make their
descent? On looking through the narrow windows, they observed a gleam
of light coming out below them on one side; probably that was from the
guard-room, and they accordingly fixed on the opposite side, where all
was dark. They ran no little chance of breaking their necks, but about
that they did not trouble themselves. If a cat could get up, they
believed that they could get down, by clinging with toes and fingers,
and teeth, if necessary, to the wall.

They, however, made the fullest examination in their power to ascertain
the best spot for their descent; they looked out of every window in
succession, but at last arrived at the conclusion that the attempt to
scramble down a perpendicular wall was too hazardous to be made. They
now began to fear that their enterprise must be abandoned, and that they
should be compelled to make their way first to a lower storey, which,
for what they could tell, might be inhabited; or else that they must
descend the creaking stairs, and run a still greater chance of being
discovered.

"Here's another window," said Bill; "let's look through that."

He climbed up to it, and gazed out. Great was his satisfaction to
perceive the top of a massive wall a few feet below him. The tower had
been a portion of an old castle, and the end of this wall was a mass of
ruins, but quite thick enough to enable them to scramble along the top
of it, and Bill had no doubt that they thence could easily descend to,
the level ground.

CHAPTER EIGHT.

THE ESCAPE--CONCEALED IN A CAVERN.

Bill drew his head in from the window, and beckoned to Jack, who
followed him up; a