you've had; you've done
wonders to get over it so soon."

"Yes, you've done well, Jack," said Sir John, who looked gratified by
the way in which his son was behaving. "Mind! keep tight hold of the
rail."

For just then the yacht made a dive, rose, shook herself, and then,
after seeming to hang poised on the summit of a green hillock, she
started again with a leap.

"Yes; better hold tight till you feel more at home. One easily gets a
heavy fall and bruises at first. But you'll soon find your sea-legs,
and give and swing with the vessel just as if you belonged to her."

"Why didn't you bring the doctor up?" said Sir John; "he is losing a
glorious sight."

"I tried hard to wake him," replied the lad, "but he was too sleepy."

"Yes; he likes his morning sleep," said Sir John.

The captain walked forward to speak to the two men of the watch, and an
intense longing came over the boy to undeceive his father, who had not
grasped the true reason of his appearance on the deck. But try hard as
he would, shame kept him silent, and he began to give way again to the
nervousness which oppressed him.

"Don't you think," he began; but his father checked him.

"Look--look--Jack!" he said; and he pointed to something about a quarter
of a mile away.

For a few moments, as it appeared and disappeared, the lad could not
catch sight of it; but at last he did.

"A serpent--a huge serpent," he cried. "Is it coming this way?"

"It, or rather they are not coming in this direction, but going on the
same chase, my boy. No, it is not a serpent; serpents do not travel up
and down in that fashion, though some people think they do, but undulate
their bodies right and left."

"But look, father," cried Jack, forgetting his nervousness in the
interest of what he saw. "It must be a great snake, you can make out
its folds as it goes along."

"No, you look--take a good long look, and don't come on deck again
without your binocular. That is a little shoal of seven or eight
porpoises. They follow one another like that, and keep on with that
rising and falling manner, coming up to breathe, and curling over as
they dive down again. They do strangely resemble a great snake."

"But breathe, father?" said Jack; "fish breathe?"

"Those are not classed as fish, my lad. They cannot exist without
coming up to get air. A fish finds enough in the water which passes
over its gills."

"Yes, I've read that," said Jack; "but I had forgotten