An "ell" is an antiquated unit of length that has been historically used in various countries, including England, Scotland, and Germany. The length of an ell could vary depending on the region and the specific purpose, but it was typically used to measure cloth or textiles. The term "ell" is derived from the Latin word "ulna," which means "forearm," as the length of an ell was often based on the length of a person's forearm.
Different regions had their own variations of the ell, but some common measurements include:
English Ell: In England, the English ell was approximately 45 inches or 1.143 meters.
Scottish Ell: In Scotland, the Scottish ell was longer, measuring around 37 inches or 0.94 meters.
French Ell: In France, the French ell, also known as the aune, was used and had its own variations, but it was typically around 1.188 meters.
Flemish Ell: In parts of Europe, including Belgium and the Netherlands, the Flemish ell was used, which was approximately 27 inches or 0.686 meters.
Earth's polar radius, often denoted as "r," is the distance from the center of the Earth to a point on the Earth's surface near either the North Pole or the South Pole. It represents the Earth's radius when measured from its center to a point along its polar axis. The polar radius is shorter than the equatorial radius because the Earth is slightly flattened at the poles and bulges at the equator due to its rotation.
The approximate value for Earth's polar radius is about 6,357 kilometers (or approximately 3,949 miles). This value may vary slightly depending on the reference ellipsoid used for modeling the Earth's shape, but the given value is a commonly used and accurate approximation for most purposes.
In contrast to the polar radius, Earth's equatorial radius (measured from the center to a point on the equator) is slightly longer, approximately 6,378.1 kilometers (3,963.2 miles).