A chain is a unit of length used in some older systems of measurement, particularly in surveying and land measurement. In the United States, one chain is equal to 66 feet or 22 yards. Internationally, it's defined as exactly 20.1168 meters.
Chains were historically used for measuring large plots of land and for surveying purposes, often in agriculture and real estate. However, the use of the chain as a standard unit of measurement has largely been replaced by the more modern and standardized metric and imperial systems, which use units like meters, feet, and yards.
The term "chain" comes from the practice of physically measuring land using a chain made of linked metal bars or wire. Each chain was typically 66 feet long, and surveyors would lay out chains end to end to measure distances across large areas. Today, modern surveying equipment such as electronic distance measuring devices (EDMs) and GPS technology have largely replaced the use of physical chains in land surveying.
A league is a unit of length that has been used historically in various cultures to measure distance, especially over land or at sea. The length of a league can vary from one region to another, and its value has changed over time.
In most cases, a league is roughly equivalent to 3 miles or approximately 4.828 kilometers. However, the exact value of a league has varied in different historical contexts and regions. For example:
Marine League: In nautical terms, a league is often considered to be equivalent to 3 nautical miles, which is approximately 5.556 kilometers. This is commonly used for measuring distances at sea.
Spanish League: In Spain and some Spanish-speaking countries, the league historically referred to the "legua," which was usually defined as 5,000 varas. The vara is an old Spanish unit of length, and the actual length of a Spanish league could vary by region. It was typically around 4.18 miles or 6.73 kilometers.
French League: In France, the league (or "lieue" in French) was historically used, and its length could vary from region to region. One French league is roughly equivalent to 4 kilometers (about 2.49 miles).
Historical Leagues: In various historical contexts and regions, leagues were used as a convenient way to measure distances over land. These leagues often had different values depending on local custom and geography.
It's important to note that the use of leagues as a unit of measurement has largely been replaced by the more standardized metric system in modern times. Therefore, leagues are not commonly used for precise measurements today but may still appear in historical documents, literature, or discussions of older measurements.