rom each side of her sharp prow; and as
they neared her the captain grew excited.

"She's going to heave to," he cried.

Just then a shot went skipping along the water, making the sea flash
into silver at every dip, and sped right on in front of the schooner's
bows, a messenger sufficiently faithful to warn the Yankee skipper of
what would be the fate of his vessel if he did not strike his colours,
for the man who aimed that shot could as easily have hulled the swift
craft.

At the captain's words every eye was directed to the American flag which
the skipper was disgracing, but it remained in its place as both vessels
sped on, and a couple more shots were fired and sent through the main
and foresails, which showed, with the aid of the glasses, a couple of
black spots.

That was all.

"He's laughing at us," growled Mr Staples. "Oh, if we could send a few
shots through his wretched craft!"

"And I dare not," cried the captain.

Just then Mark again caught sight of something which was taking place on
the schooner's deck, not five hundred yards from where they pressed on
in pursuit. It was hard to see at that distance, but he made out that a
sturdy black was evidently renewing the struggle which had taken place
before; but in spite of his efforts, he was being dragged to the side;
then, to Mark's horror, a hand was raised and a blow struck, followed by
a splash in the water, which was scattered far and wide, as the young
midshipman closed his glass with his wet hands, feeling as if it had
revealed horrors which he could not bear.

"First cutters!" rang out, and the lad ran to the boat; the captain
repeated his orders to the second lieutenant as the _Nautilus_ was run
on, so as to get as near as possible to the drowning slave before her
speed was checked and her boat lowered. There, all ready in their
seats, the boat's crew waited. The expected moment came as the sails
shivered, the boat kissed the water, the falls were unhooked, and in an
extremely short space of time the _Nautilus_ was gliding on in full
chase, and the cutter's oars were dipping in a quick, regular stroke
which took them wide of the vessel's course, as she literally darted
away.

And now, as he stood up once more on the thwart, to try and make out the
head of the black cast overboard, it struck Mark for the first time that
they were alone upon the wide sea, and that the _Nautilus_ was very
rapidly increasing her distance, while the schooner