Because of adjustments in the standard values of units of measurement over the years, a 28-second interval of time is now used in calculating a ship's speed using a rope in this way, but the basic principle remains the same.ĭictionary of Collective Nouns and Group Terms. If one knot in the rope was paid out during this time, the ship was said to be moving at one knot, or one nautical mile per hour. Eventually, the calculation of speed using this method was made easier by knotting the rope at intervals of 47 feet and 3 inches and using an hourglass that ran out after 30 seconds. As the ship moved away, the rope would pay out and sailors would count the number of knots in the rope that were paid out over a fixed stretch of time, usually measured with a sand hourglass. When the log was thrown into the water, it would remain in roughly the same place where it splashed down. A long rope was knotted at fixed intervals, wound on a spool, and tied to the end of a large wooden wedge, called the chip log or just log. The unit called the knot originated in a traditional method of measuring the speed of ships in use at least since the 16th century.
Although the knot is defined as one nautical mile per hour, the similarity in sound between knot and nautical mile is entirely coincidental. Word History: In nautical usage, knot is a unit of speed, not of distance, and has a built-in meaning of "per hour." A ship is said to travel at ten knots (and not ten knots per hour).
0 kommentar(er)
