d when Carey left," suggested the captain.
"Maybe they were put out, so the vessel couldn't move."

The steam yacht was moving slowly and those in the two rowboats were
making every effort to catch up to her. Then the black smoke began to
pour from the funnel of the _Josephine_.

"The other vessel is getting up steam," said Mr. Rover. "She may catch
the _Rainbow_ even if those in the rowboats do not."

Closer and closer to the steam yacht drew the two rowboats, until it
looked as if the _Rainbow_ would surely be boarded by the enemy.
Then of a sudden there came a cloud of smoke from the deck of the steam
yacht, followed by a stream of sparks which went whizzing just over the
rowboats. Then followed more sparks, and balls of fire, red, white and
blue.

"What in the world are they doing?" murmured Captain Barforth.

"They are shooting off something, but it is not a gun or a cannon,"
answered Mr. Rover.

"Hurrah! I know what it is!" cried Tom. "Good for Fred and Hans! Those
are my fireworks--those I had left from the Fourth of July celebration.
They are giving them a dose of rockets and Roman candles!"

This news was true, and as the rockets and Roman candles hit the
rowboats and the occupants the latter stopped rowing and then began to
back water in confusion. Soon the rowboats turned back and hastened to
the side of the _Josephine_.

"That's what I call repelling boarders!" said Captain Barforth, grimly.
"I only hope the fireworks hold out."

"It is now to be a race between the _Rainbow_ and that other
craft," observed Mr. Rover, and he was right. Inside of fifteen minutes
both vessels were headed out to sea, and running at about the same rate
of speed. Soon the haze over the water hid both craft from view.

"Well, one thing is certain," said Mr. Rover. "Our friends are alive to
their danger and are going to do their best to get away from the
enemy."

"And another thing is that we are left marooned on this isle," said the
captain.

The party remained in the tree a while longer, and then, as there
seemed nothing else to do, they descended to the ground.

"Well, we have one thing in our favor," was Dick's comment. "Sid
Merrick and his crowd must be on the _Josephine_, or they wouldn't
chase the _Rainbow_, and that being so they can't interrupt our
treasure hunt, at least for the present."

"But if they capture our steam yacht how are we to get away from here,
even if we do uncover the treasure?" said Sam.