know that Jupiter will be on the meridian at 8.32 to-night."

"Well, then, you know some more things that are worth knowin' to a sailor-man, anyhow," declared Captain Whitby.

For twenty-four hours the schooner glided along slowly and quickly, the wind constantly drawing ahead and forcing her off her course. Then it fell dead calm, and a heavy swell began to roll in from the southeast.

"Mother," said Thornton, "don't be frightened, but we're going to have a storm."

"Mercy sakes!" exclaimed Mrs. Seabury; "how do you know? The Captain hasn't said so."

"The barometer has fallen rapidly for the last six hours, and the wind has been backing from west to southwest and so on around to southeast," said Thornton, "and there's going to be a gale. The Captain hasn't said anything, because he does not wish to frighten you."

Two hours later it began to blow in short uneasy puffs from the southeast, and Captain Whitby ordered the top-sails and foretopmast stay-sail taken in. He laid the vessel by the wind on the starboard tack, intending to push out as far as possible from dangerous proximity to the coast. At six o'clock in the evening it was blowing freshly, and the long swells were cut up into foaming ridges.

"Get the fore-sail off her!" cried Captain Whitby to his little crew, and presently the big sheet of canvas was furled snugly on its boom.

"In jib, and lay aft to reef the mains'l!"

It was wild weather now, and no mistake. The big roaring green billows came raging down out of the dusk in the southeast, and as the schooner would lean far over to meet them it looked as if they were going to bury her. But as each sea approached, the schooner's bowsprit would swing upward with a great heave, the sea under-ran her, and down she came with a crash and a cloud of spray into the screeching hollow.

"I'll have to ask you all to go below," said the Captain; "it isn't safe for you to be on deck. You might get washed overboard."

Shut in the badly lighted little cabin, with the one lamp swinging madly, the agonized groaning of timbers all around them, and the thunder of tons of water falling on the deck above them, the Seaburys began to wish that they had never left their little home to go out on the treacherous ocean. They did not go to bed, but sat on the lockers, holding fast with both hands, and momentarily expecting that some terrible catastrophe would happen. About three o'clock in the morning they heard a loud shout and a heavy thump on the deck, followed by a rapid shuffling of feet.

"What can have happened?" exclaimed Mr. Seabury.

"Oh, they're coming to tell us that we must take to the life-boat!" cried Mrs. Seabury.

The cabin door was pushed open, and three sailors stumbled in, bearing the inanimate form of the Captain.

"One o' the main throat-halyard blocks fell from aloft," said a sailor, "an' hit him. I reckon he's hurt bad."

The Captain was laid in his bunk, and Mrs. Seabury forgot her fears in her anxiety to do something for him. And being one of those "handy" New England women, she could do a good deal, too. She could not find any broken bones, so she decided that the poor man had been struck on the body and injured internally. With the help of her husband, she prepared and administered a soothing drink which put the sufferer to sleep. Poor Thornton stood about idly, and keenly feeling his helplessness. But at eight o'clock he eased his mind a little by winding the chronometer.

In the mean time the storm had broken; it was only a summer gale, and at nine o'clock the wind shifted to northwest, and the sun came out. Thornton and his father went on deck, leaving Mrs. Seabury to attend to the Captain, who was awake and in much pain. The mate came up to Mr. Seabury, and said:

"This are a ser'ous business, sir."

"Yes," answered Mr. Seabury; "I suppose you're in command now."

"Waal, I am: but I wish I wasn't."

"Why, how's that?"

"Why, ye see," said the mate, scratching his head, "I kin sail the schooner all right: but I can't navigate her. I'm blowed ef I know w'ich way to steer now."

"Why not sail west till you sight land?"

"'Cause I might hit a shoal or rocks, not knowin' they was there."

"Please may I speak?" said Thornton.

"Well, what is it?" asked his father.

"I can navigate the schooner, though I can't sail her," said the boy, earnestly.

"You! Why, you never were at sea before!"

"That makes no difference," said Thornton; "sailors navigate by the sun, moon, and stars, and I know all about them. Father, I know that I can navigate this schooner into New York Bay. The chronometer is running; I know where the captain's sextant is, and I wish you'd let me try."

"We must speak to the Captain about this," said Mr. Seabury.

They went below and laid the matter before the Captain. In spite of his sufferings he became deeply attentive. He asked Thornton this question:

"How are you goin' to find the position o' the schooner now? I've lost her reckonin'."

"I'll take a chronometer sight right away, and another two hours from now, and work out the position by astronomical cross-bearings—Sumner's method, I think you sailors call it."

"Can you work Sumner's method?"

"Certainly, with sun, moon, or stars."

"Then you know more navigation than I do," said the Captain.

"It's nothing but applied astronomy, you know," said Thornton, "and I've always been studying astronomy."

"You go ahead and see what you can do, my boy," said the Captain. "Let Bowers, the mate, handle the schooner, and you tell him which way to steer."

Thornton went at once to the chronometer and set his watch by it. Then he went on deck with the Captain's sextant in his hand, and the crew stopped work to stare at him. He had a short talk with Bowers, who explained the situation to the men.

"If the Captain says it's all right," said one of the men. "I s'pose it is."

But, nevertheless, they could not understand how any person not a sailor could be a competent navigator, though the simple fact is that navigation has not necessarily anything to do with seamanship. The schooner was hove to for two hours, because Thornton explained to the mate that he desired to keep her in one place until he ascertained her position. At 11.15 the boy took his second sight and went below to work out his problem. His father stood over him in wonder while he filled a sheet of paper with sines, cosines, secants, and such things. At last the computation of the position was completed, and Thornton had to ascertain the course to be steered. He got the Captain's chart, and, marking the ship's place on it, went into the sufferer's cabin and showed it to him.

"I guess you must be about right, boy," said the Captain. "In settin' the course, you want to get well out here."

And the Captain indicated with his finger certain dangers that must be given a wide berth. Thornton set a safe course, and, going on deck, told the mate to get the schooner under way S. 1/2 W. The men sprang to their work willingly, and in a very few minutes the Three Elms was cleaving her way over a comparatively quiet sea. For three days Thornton continued his labors as navigator, and on the morning of the fourth he announced that the Highlands of Navesink ought to be sighted from the masthead at eleven o'clock. A sailor was sent up to look out for them. The hour of eleven came, and he was silent. The mate and the crew looked gravely at the anxious boy. Could he have been in error? Five minutes passed, and the men began to talk angrily. Then the man aloft cried:

"Land, ho! It's the bloomin' old Highlands! I know that lump!"

A CHEER WENT UP,