Captain Jack
said, commendingly.

"Yes; I'm on until midnight. Then Williamson stands watch until
three-thirty in the morning. After that Eph comes up and takes the
trick until it's time to call us all."

"When do I come on watch?" asked Jack.

"I never heard the captain of a craft had to stand watch in port,"
laughed Hal Hastings "Besides, old fellow, we couldn't be sure you'd
be aboard to-night. So the watches are all arranged. Anyway, you'd
better turn in and get a full night's sleep, for you've more on your
mind than the rest of us."

"Then tell Williamson, and have him pass the word on to Eph, that watch
ought to be very strictly kept," answered the young captain.

A few minutes Benson remained on deck, chatting with his chum. When he
at last went below the submarine captain lost little time getting into
his berth.

When Machinist Williamson came on deck at midnight a light wind was
blowing, but the air was not really chilly. In his heavy reefer the
machinist felt wholly comfortable after he had lighted his pipe and
started his slow walk back and forth along the deck.

There did not appear to be overmuch sense in keeping this deck watch.
Only a short distance away lay the United States gunboat "Waverly,"
with her alert marine guard. Though there was no moon, the starlight
was bright enough to enable a marine on the gunboat to see anything that
might skim over the water toward the "Benson."

Yet Williamson was on watch, under instructions, and he was a faithful
fellow who meant to do his full duty.

"Seems kinder tough, of course, to be so long out of one's bunk in the
middle of the night," the machinist admitted to himself.

Yet, had his vision been keen enough to know what was happening on shore,
almost directly opposite the "Benson," Williamson would have been
tenfold more alert.

Over there on the shore, in a clump of flowering, semi-tropical bushes,
crouched two men. On the ground with them lay a metal cylinder some two
feet long and seven inches in diameter. There was also a coil of wire
and a boxed magneto battery.

One of the pair held to his eyes a pair of night marine glasses.
Incessantly this watcher kept his gaze focused on Williamson.

About two o'clock in the morning Williamson found it necessary to go
below for a few moments. After reaching the conning tower he paused,
for a few moments, to look keenly all about him.

Yet, look as he would through the night, the machinist's