nothing.

Now ensued a great kicking and churning as Jerry's legs transformed
themselves into propellers for the salvaged "_Big Four_." Progress
was slow; the waterlogged craft lay in the river like so much
cordwood. More than once Jerry had to stop for a few minutes' rest.
But little by little he neared shore, encouraged by Dave, who
impatiently awaited the landing, wading out finally waist-deep to
help.

Neither one said a word as the boat was at last beached. No more
than the barest glance was needed to tell that there was nothing in
the boat but water. Theirs had been a fruitless chase.

"Well," said Dave, slowly, after a long silence, "I guess that ends
our last hope."

"I'm afraid you're right," agreed Jerry dejectedly. "But there's one
thing that puzzles me--do you notice how much water there is in the
boat? It's a good ten inches from the top--how full would it have
been when she popped up from under the falls at the dam?"

"She'd have been right up to the top, I suppose. Why?"

"Well, what I want to know is: How did it get out? And, what's more,
I'd like to know how it would have taken the boat all these hours to
float those few miles. Plum Run's got a six mile an hour current up
above, and it's at least four here. There's something mighty funny
about it all to me."