could hear the electric siren of
the Wonder as it was blown to let them know that their escape had been
noticed. A moment later the water, which acted as a sort of
sounding-board, or telephone, brought to the ears of Tom Swift and his
friends the noise of the engines of the other craft in operation. She
was coming after them. The race for the possession of three hundred
thousand dollars in gold was already under way. Fate seemed against
those on board the Advance.

Chapter Seventeen

The Race

Directed by Captain Weston, who glanced at the compass and told him
which way to steer to clear the outer coral reef, Tom sent the
submarine ahead, signaling for full speed to the engine-room, where his
father and Mr. Sharp were. The big dynamos purred like great cats, as
they sent the electrical energy into the forward and aft plates,
pulling and pushing the Advance forward. On and on she rushed under
water, but ever as she shot ahead the disturbance in the phosphorescent
water showed her position plainly. She would be easy to follow.

"Can't you get any more speed out of her?" asked the captain of the lad.

"Yes," was the quick reply; "by using the auxiliary screws I think we
can. I'll try it."

He signaled for the propellers, forward and aft, to be put in
operation, and the motor moving the twin screws was turned on. At once
there was a perceptible increase to the speed of the Advance.

"Are we leaving them behind?" asked Tom anxiously, as he glanced at the
speed gage, and noted that the submarine was now about five hundred
feet below the surface.

"Hard to tell," replied the Captain. "You'd have to take an observation
to make sure."

"I'll do it," cried the youth. "You steer, please, and I'll go in the
conning tower. I can look forward and aft there, as well as straight
up. Maybe I can see the Wonder."

Springing up the circular ladder leading into the tower, Tom glanced
through the windows all about the small pilot house. He saw a curious
sight. It was as if the submarine was in a sea of yellowish liquid
fire. She was immersed in water which glowed with the flames that
contained no heat. So light was it, in fact, that there was no need of
the incandescents in the tower. The young inventor could have seen to
read a paper by the illumination of the phosphorus. But he had
something else to do than observe this phenomenon. He wanted to see if
he could catch sight of the rival submarine.

At first he coul