s."

"But you can't do without sleep, sir," said the man.

"I can to-night, Tom. I've been resting and having little naps of a few
minutes at a time all day."

"Well, sir, begging your pardon, it's the rummest sort o' rest I ever
see. Take my word for it, sir, you can't hold up."

"I must somehow, Tom; so no more words. Look here, we'll seep watch
together, and the one who feels drowsy can take a nap now and then,
ready to start up at the slightest alarm."

"Very well, sir, if you won't sleep reg'lar, so be it."

But it proved to be hard work. Nature is a terrible tyrant to those who
try to break her laws, and after about an hour's duty on deck, when the
clustering stars had been watched, and their reflections in the sea, the
wheel visited again and again, an ear given from time to time at the
forecastle hatch and ventilator, where everything was silent as the
grave, all of a sudden Mark would find himself at home, talking to his
father and mother, or on board the _Nautilus_, listening to Mr Whitney,
the doctor, or to the captain, and then start up with a jerk to find he
had been asleep.

"How long was I off, Tom?" he would whisper, angry with himself.

"'Bout five minutes, sir."

"Not more?"

"No, sir."

"That's right. All quiet?"

"Yes, sir. Have another."

"Nonsense! I'm better now."

Mark took a turn to the wheel, said a few words to the steersman, and
returned to his seat, to find that in those brief minutes Tom Fillot had
gone off too, but only to start up, fully awake, at the moment his young
officer sat down.

"Look here, sir," he said; "mortal natur' won't bear it. I'll take a
trot up and down now while you sleep."

"I'm not going to sleep," said Mark, shortly.

"Begging your pardon, sir, you are," said Tom; and he took a few turns
up and down, to return at last and find Mark quite fast.

"I knowed it," he said to himself, but he had hardly thought this when
Mark started up again, vexed with himself, but unable to control the
desire for rest.

The consequence was that during the next two hours this natural process
went on, the one who sat down going off instantly to sleep, while the
other kept up his sentry-like walk, and no more words were uttered
respecting it. They felt that it was nature's work and accepted their
position till toward midnight, when Mark was resting with his back to
the bulwark, and his chin upon his breast, sleeping heavily, as he had
been for about a minu