The log-line was fastened to the chip, just us a boy loops a kite, two strings being attached at each end of the circular side, while the one at the angle is tied to a peg, which is inserted in a hole, just hard enough to keep it in place, while there is no extra strain on the board, but which can be drawn out with a smart pull.

When the log-line has run out as far as desired, there would be some difficulty in hauling in the chip while it was upright in the water; but a sudden jerk draws the peg at the angle, and permits the board to lie flat, in which position the water offers the least resistance to its passage.
The half-minute glass used on board the Young America, held by the quartermaster, was like an hour glass, and contained just sand enough to pass through the hole in the neck in thirty seconds.

The log-line was one hundred and fifty fathoms in length, and was wound on a reel, which turned very easily, so that the resistance of the chip to the water would unwind it.

The log-line is divided into certain spaces called knots, the length of each of which is the same fractional part of a mile that a half minute is of an hour.

If there be sixty-one hundred and twenty feet in a nautical mile, or the sixtieth part of a degree of a great circle, which is not far from accurate, and the ship be going ten knots an hour, she will run sixty-one thousand two hundred feet in an hour.