They rowed down the river until they entered the Mississippi, and then they set their sail again.
No other human beings were afloat on the river, at least not within the range of their vision, but there was a plenty of floating trees and other debris brought down by the spring flood.

Careful steering was necessary, but they went on without any accident.

Shif'less Sol, however, gazed up at the moon with an unquiet eye.
"She looks too soft an' fleecy," he said, speaking of the moon.

"When she's peepin' through them lacy-lookin' clouds it means that trouble is about to stir." "We'll keep a watch," said Henry.
They continued until midnight and Sol's troubles still kept off, but about that time all noticed a sudden increase of the breeze, accompanied by an equal increase of dampness.
"Something like a storm is coming and you were right, Sol," said Henry.
"Now, I wish we knew a lot about sailing." "But as we don't," said Paul, "I think we'd better take in our sail at once." They quickly did so and their precaution was wise.

The wind, blowing out of the north, began to shriek, and the boat, even without the aid of a sail, leaped forward.