"All right," agreed Porky. He turned from the rail with a last
glance seaward. He seized his brother and whirled him about.

"Look! Look!" he cried. "There it is again, straight ahead!
What's that?" Beany's keen eyes swept the sea in a lightning
glance. Then lie dashed for the companionway and fairly fell
into the presence of the Captain.

"A periscope! A periscope!" he gasped.

In another instant the Captain was on the bridge, the glasses at
his eyes. He commenced rapping out short orders.

The boys, watching breathlessly, saw the guns trained on the
little periscope which, like the reared head of a poisonous
snake, came darting at them with a swiftness which seemed
incredible. Then everything seemed to, happen at once. The
little racer on whose throbbing deck they stood swerved like a
frightened colt. Her guns spoke together; and at the same time
something slim and long cut cleanly through the water and passed
by, missing the Firefly's side so narrowly that the boys felt
their knees weaken under them. The periscope shook as the guns
volleyed again, wavered uncertainly, and sank from sight.

"We hit her!" said Beany at the rail.

The Firefly, with every ounce of steam on, dashed ahead, doubling
here and there and darting about like a frightened hare. A spot
of oil appeared on the water.