Introduction
Resource: The History of Measurement

The Distant Past
For thousands of years, measurement was a very personal thing. Often body parts were the measuring device. Because of this, measurements often meant different things to different people. Here are some examples.

• Cubit — This ancient unit of length was based on the distance from the elbow to the tip of the middle finger.

• Foot — This measure came into use after the cubit and represented the length of a human foot. Obviously, this length varied a lot.

• Inch — An inch was the width of a man’s thumb. It was also the distance from the tip of the thumb to the first joint. Twelve times this distance equaled a foot.

• Yard — Three times a foot equaled a yard. This was also the distance from the tip of the nose to the end of a man’s outstretched arm.

• Stone — Babylonians used different stones to measure different items. The stones could weigh from 8 pounds (for selling fish) to 16 pounds (for selling wool).

• Carat — Arabs used karob beans to measure the weight of gold. From this, the word carat was derived to quantify the weight of gemstones such as diamonds.

• Pace — The Romans influenced many measurements because they traded in many lands. A pace was the distance of two steps or the distance from where one foot touched the ground until that same foot touched the ground again.

Needless to say, these methods of measurement caused confusion. There were no standards that meant the same thing to everyone. In the 13th century, King Edward of England decided that a standard was necessary and decreed a “master yardstick,” which is about the same as the current yard. Further, he decreed that a foot was 1⁄3 of a yard and an inch was 1⁄12 of a foot. He later reverted back to the “old system” of using seeds and body parts for measurement.

This “standard” system was brought to America with the colonists when they settled here.

The More Recent Past
In 1793 (during the time of Napoleon), the French adopted a new system of standards, which they called the metric system, using multiples of 10 to make conversions.

• Meter — The meter was supposed to be “1 ten-millionth part of the distance from the North Pole to the equator when measured on a straight line running along the surface of the earth through Paris.”

• Liter — Intended to measure liquid volume, the liter was defined as a cube 1⁄10 of a meter on each side.

• Gram — A gram was defined as “the mass of 1 cubic centimeter (a cube that is 1⁄100 of a meter on each side) of water at its temperature of maximum density.”

Measurement in the United States
The Constitution provided for a money system that was based on multiples of 10. In 1821, John Quincy Adams wrote a report to Congress dealing with the modernization of the measurement system. This is considered the first metric study. In 1855, after some prior laws, the American Yard Standard became the law.

In 1866, the metric system began to be used in the United States. Since that time, several bills have been passed to encourage the use of the metric system because it is the standard in most of the world’s countries. In 1975, Congress passed the Metric Conversion Act, but the United States still uses the American Yard Standard measuring system. Some applications where the metric system is in use include bottled soda in two-liter containers and track-and-field events. Manufacturing companies that sell to companies overseas also use the metric system.