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.