A piece of wood was thrown from the ship into the sea, with a thin rope attached to it. As the ship sailed on, the wood remained
bobbing in the water at about the same place; the rope unwound as the ship sailed by and away from the wood. By leaving the wood, or “log” as English sailors called it, in the water for a minute . . . the seaman would know how far the ship had traveled in that time, and so work out how far it had traveled in an hour. . . . [i]f a knot were tied in the rope every one-sixtieth of a mile, all a sailor had to do was to count the knots as he pulled in the rope, and he would know how many miles per hour his ship was traveling.” How did tying knots in the rope make the job of figuring out how far a ship had traveled easier
they would know because the rope will be one sixteenth of a mile and when the rope got maxed out in length it would show how far they have traveled and the wiould calculate how far they have been in that amount of time
