Why statute mile

The US and UK agreed to standardize their length measurements in At that time, it was agreed that a yard would be equal to 0.

So one mile is 1, yards, 5, feet, or 1, This is the type of mile that everyone in these countries uses; in their cars, they drive X number of miles from Point A to Point B. In ancient Rome, the mile was divided into 5, feet. But in early Britain, greater importance was placed on the furlong, a now archaic measurement equal to 10 chains or feet. Other forms of mile include the Italian mile, which is defined as 1.

The problem with miles, especially those contrived from the paces of Roman legionaries, is that they are human measurements grounded in history but not in our understanding of the natural world. When man set out to navigate the sea, the distance of a pace, a foot, or a mile had little meaning. Navigation on the high seas, and centuries later in the air, is based on the latitude and longitude grid lines.

The nautical mile is directly created from these reference points. Both longitude and latitude are measured in degrees. Each degree contains 60 minutes, and each minute has 60 seconds. Longitude lines run north and south from the north pole to the south pole. On the other hand, the nautical mile is used for distances on the ocean and doesn't have a tangible equivalent like paces. It's a mathematical calculation based on degrees of latitude around the equator.

The equator is a circle, which we know has degrees. Each degree is divided into sixty minutes, which are not the same as the minutes on your watch. In navigation, one minute is called a nautical mile. The Roman mile was 1, paces. As the Romans defined a pace as two steps, left and right, it meant a total of 2, steps.

There are obvious problems with using inconsistent measurements such as steps, which can vary person to person, and eventually a set distance needed to be decided upon. In an act of Parliament, Queen Elizabeth I decreed that a mile was to be eight furlongs, 80 chains, rods [1], 1, yards or 5, feet. The length was statutorily decided upon in , hence the name statute mile.

As our ability to measure more and more precisely grew, it became recognized that different countries were using slightly different measurements for feet and yards, and as yards were used to measure a mile, slightly different mile lengths were being used. Various countries agreed to an international measurement of the foot to be The U.

If the mile originated with 5, Roman feet, how did we end up with a mile that is 5, feet? Blame the furlong. The furlong wasn't always just an arcane unit of measure that horseracing fans gabbed about; it once had significance as the length of the furrow a team of oxen could plow in a day.

In , Parliament set about determining the length of the mile and decided that each one should be made up of eight furlongs. Since a furlong was feet, we ended up with a 5,foot mile. So if the statute mile is the result of Roman influences and plowing oxen, where did the nautical mile get its start?

Strap on your high school geometry helmet for this one. Each nautical mile originally referred to one minute of arc along a meridian around the Earth. Think of a meridian around the Earth as being made up of degrees, and each of those degrees consists of 60 minutes of arc. Thus, a nautical mile is 6, feet.

Like the mile, the acre owes its existence to the concept of the furlong.