Dick shook his head and answered,-
"It is not the sea, Hercules."
"Not the sea!" cried the negro, "then what can it be?"
"We must wait till daybreak," replied Dick, "and meanwhile we shall have to keep a sharp look-out."
Hercules returned to his place, but only to continue listening with ever-increasing curiosity. The rumbling perceptibly increased till it became a continued roar.
With scarcely any intervening twilight night passed into day. Just in front, scarcely more than half a mile ahead, a great mist was hanging over the river; it was not an ordinary fog, and when the sun rose, the light of the dawn caused a brilliant rainbow to arch itself from shore to shore.
In a voice so loud that it awoke Mrs. Weldon, Dick gave his order to Hercules to steer for the bank:-
"Quick, quick, Hercules! ashore! ashore! there are cataracts close ahead!"
And so it was. Within little more than a quarter of a mile the bed of the river sank abruptly some hundred feet, and the foaming waters rushed down in a magnificent fall with irresistible velocity. A few minutes more and the canoe must have been swallowed in the deep abyss.