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.”
“Well, gentlemen, looking at the porpoises?” said the captain, coming up behind them. “Nice little school of them. They always go along like that. I used to think when I first saw them that they were like a troop of boys running along and leaping posts. They’re after a shoal of fish; mackerel perhaps. Well, Sir John, how do you think the yacht runs with this breeze?”
“Splendidly,” said Sir John.