Rollo on the Atlantic

by Jacob Abbott

At length the man who holds the log throws it over into the water, and the ship, sailing onward all the time, leaves it there, floating edge upwards. The man who holds the reel lifts it up high, so that the line can run off easily as the ship moves on. As soon as the first rag runs off, which denotes the beginning of the marked point of the line, he calls out suddenly,—

"Turn!"

This is the command to the man who holds the minute glass to turn it so as to set the sand to running. He accordingly instantly changes the position of the glass, and holds it perpendicularly, and immediately sets himself to watching the running out of the sand. The instant it is gone, he calls out,—

"Stop!"

The man who is holding the reel, and another who stands by ready to help him, instantly stop the line, and begin to draw it in. They observe how many knots have run out, and they know from this how many miles an hour the ship is going. Each knot goes for a mile.

They do not have to count the knots that have run out. They can always determine, by the form and color of the last one that passed, what knot it is. One of the men goes immediately and reports to the captain that the ship is going so many knots, and the captain makes a record of it. The other men at once begin to draw in the line, which brings the log in also at the end of it. This line comes in very hard, for the friction of so long a cord, dragged so swiftly through the water, is very great. It generally takes four or five men to pull the line in. These men walk along the deck, one behind the other, with the line over their shoulders; and at first they have to tug very hard. The reel man winds the line upon the reel as fast as they draw it in. It comes in more and more easily as the part that is in the water grows shorter; and at length the log itself is soon skipping through the foam in the wake of the ship, until it comes up out of the water and is taken on board.

They heave the log every two hours,—that is, twelve times for every twenty-four hours,—and from the reports which the captain receives of the results of those trials, it is easy for him to calculate how far the ship has come during the whole period. As he knows, too, exactly how far the pilot has been steering by the compass all this time, he has both the direction in which the ship has been sailing, and the distance to which she has come; and, of course, from these data he can calculate where she must now be. This mode of determining the ship's place is called by the reckoning. The other is called by observation.

The intelligent and reflecting boy who has carefully read and understood the preceding explanations will perceive that the two operations which we have been describing are in some sense the reverse of each other. By the former, the navigator ascertains by his measurements where the ship actually is to-day, and then calculates from that how far, and in what direction, she has come since yesterday. Whereas, by the latter method, his measurements determine directly how far, and in what direction, the ship has come; and then he calculates from these where she now is. Each method has its advantages. The former, that by observation, is the most sure and exact; but then it is not always practicable, for it may be cloudy. On the other hand, the latter—that is, by the reckoning—never fails, for the log can always be thrown, be the weather what it may; but it cannot be fully relied upon, on account of the currents in the water and the drifting of the vessel. Consequently, on board all ships they keep the reckoning regularly every day. Then, if they get a good observation, they rely upon that. If they do not, they go by the reckoning.

We now return to the story. And here, I suppose, is the place where those sagacious children, who, when they are reading a book in which entertainment and instruction are combined, always skip all the instruction, and read only the story, will begin to read again, after having turned over the leaves of this chapter thus far, seeing they contain only explanations of the mode of navigating a ship, and saying nothing about Hilbert and Rollo. Now, before going any farther, I wish to warn all such readers, that they will not be able to comprehend at all clearly the complicated difficulties which Hilbert and the others got into in respect to the lottery without understanding all that has been explained in the preceding pages of this chapter. I advise them, therefore, if they have skipped any of it, to go back and read it all, and to read it slowly too, and with the utmost attention. And I advise them, moreover, if they do not perfectly understand it all, to ask some older person to read it over with them and explain it to them. If they are not willing to do this, but insist on skipping the first part of the chapter, I advise them to make complete work of it, and skip the last half too; for they certainly will not understand it.

When Hilbert went back to the paddle box with his half sovereign, it was about eleven o'clock. The observation was to be made at twelve; and the results, both in respect to the observation and the reckoning, were to be calculated immediately afterward. The lottery which the men were making related to the number of miles which the ship would have made during the twenty-four hours. The men were just making up the list of subscribers to the tickets when Hilbert went up to them. He gave his half sovereign to the man who had the list. This man whom they called the Colonel, took the money, saying, "That's right, my lad," and put it in a little leather purse with the other half sovereigns.