With a turn of his wrist Mr. Henderson moved the wheel which
controlled the tube. It was deflected and sent the boat to larboard.

At that instant from the rock two small fountains of water rose in the
air, falling back in a shower of spray through which the sun gleamed.

"That's not a rock! It's a big whale!" cried Jack. "And we're going to
hit him!"

The professor had miscalculated the speed of the craft, or else had
not thrown her far enough to larboard, for, a second later, the
Mermaid was almost upon the big leviathan.

With a desperate twirling of the steering wheel the professor veered
the craft as far as possible. But all he could do did not suffice, for
the craft hit the whale a glancing blow on the side, and the ship
careened as if she would turn turtle.

At the same time there rang out from upon deck the sound of a rifle
shot. Old Andy had taken a chance at the enormous creature of the
deep.

"Hurrah!" the bays heard him shout. "I give him one plumb in the eye!
A fine shot! And we hit him besides with the boat. I guess he's a
goner!"

"I'm afraid not," muttered the professor. "That was a bad blow we
struck him, but I think it will only ruffle his temper. We'll have to
look sharp now, boys."