"The heavy rains are responsible for this," said Snap. "We want to
be careful, or the boat will be smashed on some of the rocks."

"We might get out and walk---that is, some of us---if the shore
wasn't so rough and rocky," said Whopper. "It looks wilder than
ever now, doesn't it, boys?"

It certainly did look wilder---or was it only the rushing of the
water that made it appear so? They rowed on with caution, two
at the oars and two doing the steering with poles. Wags sat in
the bow as before, watching proceedings in silence.

About half the distance to Firefly Lake had been covered when they
came to a sharp turn in the watercourse. Here the water boiled and
foamed around several sharp rocks.

"Beware of the rocks!" sang out the doctor's Son.

"To the right! To the right!" yelled Whopper. "It's too shallow
on the other side!"

They tried to turn the craft to the right, but the current seemed
too strong for them. The boat swung around and hit one of the
rocks a sharp blow. There was a little splash as the collie went
overboard. Then came a big souse, that covered those who remained
in the boat with spray.

"Giant is overboard!" cried Whopper. "And so is the dog!"

"Let the dog take care of himself," cried Snap. "Grab Giant!"