ds heard from the cavern-mouth overnight.

In all probability it was a fisher's song which the people imagined had
some effect upon the fish they were trying to lure to their nets.
Strangely wild and mournful, it rose and fell, and gained at times in
force as it seemed to echo from the right side of the canon, which here
rose up like some gigantic wall hundreds of feet in height, barred with
what appeared to be terraces, and honeycombed with open doors and
windows, row above row, from the lowest, upon which in two places
smouldered the remains of fires, right up to the sky-line, which,
roughly regular, was carved into something resembling the crenellations
of a gigantic castle, extending apparently hundreds upon hundreds of
yards.

Brace had hardly swept the face of the strangely-worked range of cliff
when the softly mournful chorus ceased, and as if moved by one impulse,
on catching sight of the approaching boats, the Indians burst forth into
a shrill piercing yell which echoed and re-echoed discordantly from the
face of the rocks. The next moment every man had seized his paddle, and
they were making the river foam and sparkle with the vigour of their
strokes.

There was no mistaking the effect produced on the Indians by the
appearance of the boats: it was the feeling of horror and dread, every
man plunging his paddle deeply into the water and striving his utmost to
force the canoes to their greatest speed, so that they might escape from
the strange beings. In all probability they were seeing white men for
the first time in their lives.

"What does that mean?" said Brace: "going to fetch help?"

"No," said Lynton; "because this must be where they live."

"Yes; there are their fires on the banks," added the captain.

"But they are mere savages," said Sir Humphrey, who ceased to watch the
retreating Indians, to sweep the front of the towering cliffs with his
glass. "This palace must have been the work of a more highly civilised
race."

"And is it your opinion that they are at home, waiting to shoot?" asked
Briscoe, stooping to pick up his gun.

"At home? No," cried Sir Humphrey: "those are the ruins of some
extremely ancient rock city. Look, Brace. Use your glass. It is the
work of centuries. I should say every place has been cut and carved out
of the solid rock by some industrious race; but it is quite deserted now
save by birds."

"Then we've made a find," said Briscoe excitedly. "I say, I wonder