ught to do at once. Such a performance is called a "crash dive."

"I'd like to see him come up so near that we could ram him," said the
captain, gazing almost directly into the sun. "Find out what she's
making."

[Sidenote: Getting up speed.]

The engineer lieutenant stooped to a voice-tube that almost swallowed up
his face, and yelled a question to the engine-room. An answer came,
quite unheard by the others.

"Twenty-four, sir," said the engineer lieutenant.

"Get her up to twenty-six."

The engineer cried again through the voice-tube. The wake of the vessel
roared like a mill-race, the white foam tumbling rosily in the setting
sun.

[Sidenote: Seventy feet below the surface.]

Seventy feet below, Captain Bill was arranging the last little details
with the second in command.

[Sidenote: The plan of attack.]

"In about five minutes we'll come up and take a look-see [stick up the
periscope], and if we see the bird, and we're in a good position to send
him a fish [torpedo], we'll let him have one. If there is something
there, and we're not in a good position, we'll manoeuvre till we get
into one, and then let him have it. If there isn't anything to be seen,
we'll go under again and take another look-see in half an hour. Reilly
has his instructions." (Reilly was chief of the torpedo-room.)

[Sidenote: Wreckage all about.]

"Something round here must have got it in the neck recently," said the
destroyer captain, breaking a silence which had hung over the bridge.
"Didn't you think that wreckage a couple of miles back looked pretty
fresh? Wonder if the boy we're after had anything to do with it. Keep an
eye on that sun-streak."

[Sidenote: A crash dive to avoid a destroyer.]

An order was given in the _Z-3_. It was followed instantly by a kind of
commotion--sailors opened valves, compressed air ran down pipes, the
ratchets of the wheel clattered noisily. On the moon-faced depth-gauge,
with its shining brazen rim, the recording arrow fled swiftly, counter
clockwise, from seventy to twenty, to fifteen feet. Captain Bill stood
crouching at the periscope, and when it broke the surface, a greenish
light poured down it and focused in his eyes. He gazed keenly for a few
seconds, and then reached for the horizontal wheel which turns the
periscope round the horizon. He turned--gazed, jumped back, and pushed
the button for a crash dive.

"She was almost on top of me," he explained afterwards, "coming like
hell! I h