d the boat careened
over so dangerously that, if the man who held the sheet had not hastily
let go so that the sail went flying, the mate would have gone over the
side, and would soon have been left behind, as the boat was now going
along at a considerable speed.

It was only a matter of a moment or two, and then the tiller was
steadied, the sheet hauled home, and the boat glided swiftly on once
more.

"I say," cried Briscoe, as Dan sat grinning with delight, "what's it all
about?"

"About?" cried Lynton angrily; "why, my bait was taken by either a shark
or an alligator. There's a hundred yards of new line gone. What's to
be done now?"

"You'd better rig up another, I should say," said the American drily,
"and hold on and give out when the fish runs."

"It's a rum un," muttered the mate. "I say, my lad, just keep your head
out of my way next time. Are you aware that it's just about as hard as
a cocoanut?"

"Never mind, Lynton," cried Brace. "Get out another line as soon as you
can, while the fish are biting so freely."

"I don't know about that. The old man will kick up a row about that
line being lost. It was his, and he'll want to know how it came about
that I lost it."

"Never mind: we brought plenty with us. Look sharp."

CHAPTER TWENTY ONE.

A RIVER MONSTER.

The boat's way was checked, and every eye was now fixed upon the second
mate as he prepared and threw out another artificial bait. At the same
moment the sail was allowed to fill, and the boat glided on once more.

"They don't get this line," said Lynton confidently, "for I'll hold it
all the time. Let her go, Dan: take a pull on that sheet."

The boat answered to the drag as if she had been a spirited horse
resenting a touch at the curb rein, and away they went, with the water
surging up towards the gunwale as she careened over.

They had sailed on for a few minutes when a loud cry came from the mate.

"Ahoy there! Oh, murder!" he yelled. "Throw her up in the wind, or I
shall have my arms dragged out of their sockets."

For just when least expected there was a tremendous jerk as some fish or
reptile snatched at the flying bait, and Lynton was scarcely able to
keep his hold of the line.

"Let him run," cried Brace. "Give him plenty of line."

For the moment the mate was too much taken by surprise to act, but,
recovering himself while one of the men snatched up and loosened more
line from the winder, he let out yard afte