ght as they advanced.

"It is the chasm, or sink, where the roof of the cave has fallen in,"
said Penn.

While he spoke, a muffled rustling of wings was heard above their heads.
They looked up, and saw numbers of large black bats, startled by the
torches, darting hither and thither under the dismal vault. Birds, too,
flew out from their hiding-places as they advanced, and flapped and
screamed in the awful gloom.

To save the torches for their return, Cudjo now extinguished them. They
walked in the brightening twilight along the bank of the stream, and
found, to the surprise and delight of Virginia, some delicate ferns and
pale green shrubs growing in the crevices of the rock. Vegetation
increased as they proceeded, until they arrived at the sink, and saw
before them steep banks covered with vines, thickets, and forest trees.

The river, whose former course had evidently been stopped by the falling
in of the forest, here made a curve to the right around the banks, and
half disappeared in a channel it had hollowed for itself under the
cliff. Here they left it, and climbed to the open day.

"How strangely yellow the sunshine looks!" said Virginia. "It seems as
though I had colored glasses on. And how sultry the air!"

She looked up at the towering rocks that walled the chasm, and at the
trees upon whose roots she stood, and whose tops waved in the summer
breeze and sunshine, at the level of the mountain slope so far above.
She could also see, on the summit of the cliffs, the charred skeletons
of trees the late fire had destroyed.

"It was here," said Penn, "that Stackridge and his friends escaped. This
leaning tree with its low branches forms a sort of ladder to the limbs
of that larger one; and by these it is easy to climb----"

As he was speaking, all eyes were turned upwards; when suddenly Cudjo
uttered a warning whistle, and dropped flat upon the ground.

"A man!" said Carl, crouching at the foot of the tree.

Penn did not fall or crouch, nor did Virginia scream, although, looking
up through the scant leafage, they saw, standing on the cliff, and
looking down straight at them, at the same time waving his hand
exultantly, one whom they well knew--their enemy, Silas Ropes.

XLI.

_PROMETHEUS BOUND._

At the wave of the lieutenant's hand, a squad of soldiers rushed to the
spot. In a minute their muskets were pointed downwards, and aimed.
"Fly!" said Penn, thrusting Virginia from him. "Carl, take her