Currently, two different systems of measurement have been widely standardized: the Imperial System, used mainly in the United States, and the Metric System, which is officially used throughout most of the world. The universality of these two systems has been perfected from globalization throughout history. Interestingly, if you analyze the units used in these standardized systems, you can see the different systems that were eliminated to increase the interoperability between different peoples and nations.
Systems of measurement have been around for thousands of years, since they were needed for many kinds of construction and design. The original forms of measurement were based on units relative to the human body, which often created successful guidelines, since this method just took advantage of natural standards. People were born with two arms and ten fingers, which worked well as units of measurement.
The earliest arm-based unit was the Egyptian cubit, which the ancient people needed to create dams for the Nile Delta and construct the pyramids. The cubit was measured by the length of the arm, from the elbow to the tip of the extended finger. This was divided in a remarkably complicated way, broken up into the basic subunit, the digit, which was the breadth of the finger and went into the cubit 28 times. Four digits equaled a palm, five a hand, twelve a spall span, fourteen a large span, and sixteen made one t’ser. These different units could be converted into one another. For example, seven palms equaled one cubit. The accuracy of this system can be observed through the success of the cubit-constructed Great Pyramid of Giza, which sides all differ by less than one foot.
Even though these systems operated with little issue in the individual regions where they were located, they later benefitted from the precision that came with standardization. Basing units on body parts can obviously lead to problems with system interoperability, since people vary physically. The success of the structures in Egypt might have been attributed to construction being performed by people of a similar stature. Transferring these units to people of different classes or cultures could have easily led to problems, since there would be a much greater likelihood of variation in body part proportions. Another issue that would have made these ancient units difficult to standardize is cultural adaptability. Some outdated units of measurement were based on things that were specific to the cultures that used them. For example, prior to the 19th Century in Ireland, the cow was the measure of most things, and a “cow’s grass” was often the effective unit of land measurement. This would not have been the most universal unit to standardize, and it would seem out of place today if a real estate agent had to describe an urban home by its cow’s grass.
Despite the cultural individuality of some past units of measurement, some of them have actually been standardized into the Metric and Imperial Systems. For example, there was an Anglo-Saxon unit of length known as a barleycorn, which was traditionally the exact length of a specific barleycorn. Now, this unit has been standardized into the Imperial System as 0.33 in, or 8.5 mm, and is used today as the primary method to measure shoe sizes in the UK and the US. So, the difference between a size 8 shoe and a size 9 is one barleycorn.
|Barleycorn, the unit for shoe sizes|
For some time, leaders in Britain felt there was a need to standardize the many units of measurement that had been used throughout the nation’s rich history. The Imperial System was derived greatly from the measurements that were used by the Romans. Important concepts taken from the ancient system include uncia, the base unit that became the modern inch, pes, which was comprised of 12 unciae and became the modern foot, and mille, which was the basis for the modern mile. The measurements for these were determined by using the average foot length of the Roman Centurion. These units had to be altered slightly for incorporation into the Imperial System, but the base of 12 units still remains today.
Royalty had a great impact on the adaptation of these Imperial measurements. For example, it is thought that King Henry I decreed that a yard should be the distance from the tip of his nose to the end of his outstretched thumb, which was approximately three feet. The Tudor rulers established that a furlong is 220 yards, later encouraging Queen Elizabeth I to declare in the 16th Century that one mile should be 5280 feet, not the traditional Roman 5000 feet. This made one mile exactly eight furlongs, creating a convenient relationship between the two. Several royal edicts in the 18th Century gave England a higher degree of standardization than other nations, which also implanted the Imperial System into its many colonies and territories.
The Metric System was first adopted following the French Revolution. There was a need for measurement standardization, since at the time there were 300 different units that could be used to measure land in France. The Metric System has specific units that are based off of 10, which makes it easy to understand and very convenient for conversions. However, according to History, the Metric System in France did not originally last long in retail, being abolished by Napoleon in 1812, but it was later reinstated in 1840. By then, many countries had begun to adopt it.
After near-universal adoption of the Metric System, there were still some nations that initially not abide to the process of metrication. Other than countries such as the United States, which used the Imperial System, some places continued to use their traditional units of measurement that had been around for centuries. For example, prior to its adoption of the Metric System in 1925, China primarily used a unique system of measurement that contained base units of 16. Despite this change, ever since the Metric System has been implemented in China, the now-superceded units of measurement continue to be used for weighing goods in stores.
The Imperial System has been altered to be used in the United States as US customary system, and the Metric System, as the International System of Units (SI), is used by the majority of the world, with the exception of the US, Liberia, and Myanmar. However, the Imperial System is still used for particular purposes in the metricated world. For example, the United Kingdom displays miles per hour as the speed limit and measures beer and milk in pints.
Today, in the United States, standards for weight and measurement are monitored by the National Institute for Standards and Technology (NIST). Traditionally, the Metric System is used for measurements and calculations in scientific standards. However, there are some exceptions, such as SAE J 2271-2009 (SAE J2271-2009): Ship Systems and Equipment - Part Standard for Studs - Continuous and Double End (Inch Series), which provides guidelines for materials used for constructing ships and uses inches as the main unit of measurement.
Even with only two systems of measurement, there can still be confusion. In 1999, due to misunderstanding originating from one organization using SI units, while the other used US customary units, a $125 million Mars orbiter was lost in space. Maintaining coherent systems of weight and measurement with clear distinctions between the two is essential.