as willing, for I don't feel at all sleepy yet," was the
answer.

"Yes: let's have a look at the stars and the river before we lie down,"
said Brace; and they strode quietly out till they were at the extreme
edge of the shelf, with the black darkness below them and the river
sparkling and spangled with the reflections of the stars which glowed
brilliantly in a long wide band overhead, the cliffs cutting off a vast
amount of the great arch.

"I'm glad that fire's well out," said Briscoe quietly, as he looked
back. "Indians are not very likely to be about at night, but if a canoe
were coming along the river and the paddlers saw a fire up there, you
may depend upon it they would land to see what was the matter."

"That's for certain," said Lynton. "Do you think it likely that those
chaps we ran down belong to the same tribe as those we saw in the canoe
yonder before we landed?"

"It's hardly likely," said Briscoe. "I fancy the natives of these
regions are cut up into little bits of tribes scattered here, there, and
everywhere about the forest."

"Pst! Be quiet a minute," said Brace, and all listened.

"What is it?" asked Briscoe, at the end of a minute.

"I heard a peculiar noise while you were speaking, but it is still now."

"Birds--night-birds," said Briscoe. "Our friends of the cavern
grumbling because we've turned them out."

"Oh, no; I don't fancy it was that," said Brace hurriedly. "It sounded
like human voices singing in chorus."

"Our fellows below in the boat," said Lynton, "only they wouldn't be
singing."

"Oh, no; it was not that," said Brace.

"Might be anything," said Briscoe, yawning. "Frogs, perhaps, down by
the water-side."

"No: I'm pretty well used to the night sounds we hear," said Brace
impatiently. "Ah, there it is: listen."

He was silent, and as if reflected from the cliff there came a low
musical sound, very soft and sweet, and, as he said, as if many voices
were raised far away in a kind of chorus which reverberated from the
sides of the canon, reaching in a soft murmur to where they stood
listening.

"H'm!" ejaculated Briscoe, after listening till the sound died softly
away. "Can't be any band having a concert on the next street."

"And I should say it isn't a boating party returning down the river from
an outing, singing glees," said Lynton.

"I've heard of singing-fish," said Brace. "There's not likely to be
anything of that kind in the river, is there?"

"No,"