hard
Swayne interested in our Girls' Branch Athletic League, and so we are to
have a fine new field, they say. That's enough for Laura to do."

"But Mother Wit is always turning up unexpectedly with something new,"
laughed Dorothy. "And she says we must have a new shell in time to use
it in the race on the big day."

"Who's launch is that, Dory?" asked her sister, suddenly.

A motor-boat had just come into sight around a point of the island
ahead.

"Why--why----Isn't that Pretty Sweet's _Duchess_?" asked Dorothy.

"Maybe. It's missing explosions dreadfully. Nasty thing! I don't like a
motor boat."

"Well, a canoe or a sailboat is more fun, I believe, unless you want to
go fast," said the other twin.

"Speed up, Dory. We can cross the bow of that boat. It _is_ Purt's
boat."

"And there are two other boys aboard."

"Chet and Lance, I declare!"

"Laura said she and Jess were coming over to the island to-day; funny
the boys aren't with them."

"Then somebody else would have to go with Purt, for he could never run
that motor alone. Oh, look!"

As Dorothy spoke there was a big puff of smoke from the middle of the
launch and they heard the boys shouting excitedly.

[Illustration: AS DOROTHY SPOKE THERE WAS A BIG PUFF OF SMOKE FROM THE
MIDDLE OF THE LAUNCH.]

"Now you've done it, Purt!" was an exclamation the twins heard.

Then flames shot up where the smoke had been and the twins both cried
out.

"Their gasoline's afire! It's the tank!" exclaimed Dora.

She had scarcely spoken when there came a muffled report, another great
balloon of smoke, and the launch seemed to be afire from end to end. Out
of the smoke and flames three figures, one after the other, leaped into
the lake, while the burning launch darted on across the path of the
girls' canoe.

CHAPTER II

MISSING: THE SHORT AND LONG OF IT

"Oh! Oh!" cried Dora. "I hope they're not burned."

"But they'll be drowned!" gasped her sister.

"Chetwood Belding and Lance Darby won't drown, that's sure," returned
Dora, but driving in her paddle vigorously.

"No, they can swim."

"And they won't let Prettyman Sweet drown, either."

The girls swept on at a splendid pace, paying no attention to the
runaway and burning launch. They were anxious to reach the struggling
boys.

"We can't take them aboard, Dora!" cried her sister.

"Of course not; but they can cling to the gun-wales----"

"And sink us."

"No, they won't."

"They'll tip us