Let's say you have a YouTube channel, and let's say that you want to do a video on a car race.
Now if you have viewers both inside, and outside the United States, that raises a challenge for
you. Because as the cars are racing, the viewers are going to demand that you show their speed in
both metric units, that is kilometers per hour, and US customary units, that is miles per hour,
or else somebody will complain. That's not a hypothetical scenario, it actually happens. I
can tell you that from direct experience. But it does raise an interesting question, and that is,
why is the United States, which is the world's largest economy, and in fact has been the world's
largest economy since 1871. One of only seven countries on earth, has not officially adopted
the metric system as their primary system for weights and measures. There's actually a term
for how a country moves to the metric system, it's called metrication. And the history of
metrication is actually quite interesting. It is history that deserves to be remembered.
Standard systems of weights and measurements are of great value to trade, and are evident in many
ancient civilizations. There's evidence that by 500 BC, the Greek Empire had standardized
their system of weights and measures, and required merchants to test their measuring devices against
official standards. For example, the Greeks developed the measure pous, meaning foot, which
was 16 daktylos, or fingers. By looking at ancient descriptions of still existing examples of Greek
architecture, we're able to determine that a pous was three hundred eight point two millimeters, or
twelve point one three inches. The Hellenic system appears to have been influenced by Mesoptamian
systems. Standards of measurement in the ancient Akkadian Empire were issued as early as the 24th
century BC. The Roman system was relatively well documented, and the pes, or Roman foot,
was somewhat smaller than the Greek pous. While the finger and foot were common ways for ancient
civilizations to measure length, weight often started with the measure of a grain of wheat.
The development of the English system of weights and measures was based on Roman and anglo-saxon
systems of weights and measures. The earliest record of English measures had to do with Saxon
coinage. In 1527, the weight of the English penny was 24 grains. That was called the pennyweight,
and it formed the basis of the troy units of weight which are still used today for
weighing precious metal. King Henry the seventh established a system of measure in 1495 derived
from the system of measurements created in the ancient kingdom of Wessex, using a bushel which
could be further divided into pecks, dry gallons, dry quarts, and dry pints. Yes,
the peck was in use for centuries before the first known publication of the tongue twister,
“Peter Piper picked a peck of pickled peppers” in 1813. That system, which later would become
known as the Winchester system, was clarified and expanded by Queen Elizabeth the first in
1588 with the Exchequer Standards. The system was still rather confusing, for example, a gallon of
ale was measured by volume, and a gallon of wine was measured by weight. The system was finally
standardized with the Weights and Measures Act of 1824, creating the Imperial Standard,
which came into use throughout the British Empire, and is still the official system of measurement
used today by the independent state of Samoa. The Imperial Standard standardized many measures still
recognized, and used in various contexts today, such as miles, furlongs, fathoms, and acres. But
the Weights and Measures Act came after the United States had earned its independence,
thus the US system, called United States Customary Units, is also based on the older English system,
but differs in many ways from the Imperial system. For example, a US gallon is slightly
more than 83% of an imperial gallon, and thus, car mileage ratings rated imperial gallons will
be higher than miles per gallons ratings offered by the American Environmental Protection Agency.
The yard and the pound were standardized based on the British counterparts, but many other US
customary measurements vary by state, and industry. Most Americans do not understand
the complexity of their own system, even today. For example, what's a bushel? According to the
Chicago Mercantile Exchange, a bushel of corn is 56 pounds, while a bushel of oats is 38 pounds.
The idea of a simpler system that was derived from Standard Natural Measures is largely attributed
to a 17th century French abbot and scientist, named Gabriel Mouton. Using an approach typical
of the thinking in the Age of Enlightenment, he suggested standard measures based on, for example,
the length of one minute of the Arc of the Great Circle of the Earth. Something today called the
nautical mile, or the length of a pendulum with a frequency of one beat second. The
system fit the Republican political motivations of the French Revolution. The French National
Assembly devised the system in 1790, in the midst of the French Revolution. The unit of length was
to be a portion of the Earth's circumference, measures for volume and mass were derived from
the unit of length. In that way, the basic units of the system were related to each other, and to
nature. Larger and smaller multiples of each unit were created by multiplying or dividing the basic
units by 10. The basic unit was named the meter, derived from the Greek word meaning measure,
which was equal to one ten-millionth of the distance from the North Pole to the equator along
the meridian running near Dunkirk to France, and Barcelona and Spain. A measure that took six years
to determine and was actually not quite accurate, but has nonetheless remained the standard.
Other measures were all derived from there. The system makes sense, and is much easier on users,
but changing from traditional measures used for centuries was not a simple process. Much
of the reason that the metric system became the international standard had to do with the unique
situation in Europe in the 19th century. As once disparate peoples formed unified nations in Italy,
Germany, and the Netherlands, the metric system was a simple compromise among competing local
systems. Portugal and Spain largely shifted to facilitate trade with France, which then drove
metrication in Central America, where emerging nations were eager to embrace modernity. Other
nations joined both for simplification, and in the name of international trade, although many
still retain various bits of previous systems. The United Kingdom was particularly resistant to
changing from its own Imperial system. In 1965, the UK committed to the process of metrication,
largely to better facilitate trade with Europe. Metrication has not always been popular in the UK,
but through a series of regulatory measures, has metricated most trade and retail. There are
notable exceptions especially in transportation, where road signs and distant markers still use
imperial units, and only limits on vehicle height or width might be listed in metric
units. Polls still show considerable resistance to further changes. Metrication in the UK helped
to drive metrication throughout the Commonwealth. China began the conversion under the nationalist
government in 1925, but many traditional Chinese units continued to be used until the State Council
the People's Republic of China mandated that they be transitioned by 1990. But how is it that the
US, who along with its dependent territories of the federated states of Micronesia, the Marshall
Islands in Palau, and the country of Liberia still have not committed to full metrication,
and continue widespread use of US customary units. The difference impacts international trade,
but the effect has been more direct. In 1999, the nearly two hundred million dollar Mars Climate
Orbiter was lost due to a calculation error that was the result of a contractor calculating in US
customary measurements, and NASA calculating in metric measurements. That question is particularly
interesting since the US was a particularly good fit for metrication. Thomas Jefferson,
who had been instrumental in devising the decimal-based US coinage system had suggested the
similar system of weights and measures in 1790. In 1866, Congress passed the law which allowed,
but did not require, the use of the metric system. Unlike Great Britain the US had been a signatory
of the 1875 Metre Convention, which created the International Bureau of Weights and Measures,
and has as its purpose, designing and standardizing the metric system. Between
1895 and 1987, it was required to teach the metric system in US public schools. And more directly,
and unknown to most Americans, since an 1893 decision by Thomas Mendenhall,
director of the US Coast and Geodetic Survey the fundamental standards of length and mass for the
US customary system is based not on the Imperial standard, but in relation to the metric system.
So while we continue to use yards and pounds, those are actually defined in terms of meters and
kilograms. The numbers changed in 1959, but the actual definition of a US yard is 0.9144 meters.
So why do we still use yards, gallons, pounds, and temperature fahrenheit? Certainly there is a
financial cost involved in changing machinery, and designs. But much of the reasoning has to do with
tensions between the United States, and France at the point that official US weights and measures
were being determined. Despite French assistance during the American Revolution, relations soured
towards the end of the 18th century, and the USA and France neared war over the 1795 Jay Treaty,
and the XYZ affair. In 1798, when France invited foreign dignitaries to come and view the new
metric system, France declined to invite the United States. Supporting the system was seen
as unpatriotic, an attitude that endured. An 1883 song written by influential poet C.A.L.
Totten included these lines. “Then down with every metric scheme. Taught by the foreign school. Will
worship still our fathers God, and keep our fathers rule. A perfect inch, a perfect pint,
the Anglos honest pound. Shall hold their place upon the earth, till times last trump
shall sound.” There were practical complaints as well. The metric system seemed only as stable as
the French Revolution, and there was a concern it would collapse. In fact it briefly did. Some
metric measures depended literally on French territory, and there was a concern that the US
would not have possession of standard measures. At a critical point when the change made sense,
the metric system's French origin entrenched the US customary measures. And finally,
there were the pirates. In 1793, Thomas Jefferson asked French naturalist Joseph Dombey to acquire a
standard kilogram that could be used as the basis for US measures. On his return trip,
Dombey’s ship was blown off-course and he was captured by pirates. He died in captivity. Is
it possible that the US may have made a different choice had pirates not stolen
our perfect kilogram at a critical time when decisions about the US system were being made?
Of course none of this explains why the US hasn’t made the change since, just like Great Britain did
in 1965. There are essentially two answers to that question. The first answer is we already
largely have. The process of metrication is fairly advanced in the US. Most scientific work,
the field of Medicine, and the US military all operate exclusively by metric measures.
As a result of the 1999 Mars Climate Orbiter loss, so does NASA. The metric system is used
by more than people seem to realize. Americans no longer buy liquor by the traditional fifth,
or one fifth of a gallon, and instead the standard bottle is now 750 milliliters. Community races are
now mostly run not in miles, but in k’s. The second answer to the question is that
the government has not forced us to. Part of the forgotten history of metrication is that in almost
every country where the metric system has been enforced, the people in the country ignored the
system and continued to use their traditional measures until they were literally forced to
change by the government. Even in France, the people largely ignored, and mistrusted the metrics
system until they were essentially forced to convert under Emperor Louis Philippe. Government
attempts to enforce the metric system were a primary driver behind the deadly Quebra-Quilos
revolt in Brazil in 1874. Some traditional measures simply have too strong a traditional
following. That is why you can still get draft beer by the pint in Great Britain and Ireland.
While the US has made multiple laws requiring the metric system be taught in schools,
requiring that products be labeled in metric units, requiring that government contracts be
done by the metric system, the United States has never required that private business be
conducted using the metric system. So Americans continue to embrace their customary measures,
because they're given that choice. We choose to watch NASCAR in miles per hour,
we choose to require 10 yards to get a first down. And history tells us that much of the
rest of the world would have made the same choice, if their government had allowed them to.
I'm the History Guy, and I hope you enjoyed this edition of my series of short snippets
of forgotten history about 10 minutes long. And if you did enjoy it, please go ahead and click
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feel free to write those in the comment section, I will be happy to personally respond. And
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