How the U.S. Got Its Seemingly Random System of Measurements

Behind every measurement is a fascinating origin story

Photo byRodolfo Clix on Pexels

One of my all-time favorite Saturday Night Live (SNL) skits has just been given a part 2. In both the original and the sequel, guest host and popular comedian Nate Bargatze plays the United States’s first President, George Washington. Bargatze’s Washington, in the midst of the War of Independence, tries to inspire his soldiers to fight on by reminding them what they’re fighting for: the right to label and measure things in completely random ways.

He begins his speech by saying, “I dream that one day our proud nation will measure weights in pounds, and that 2,000 pounds shall be called a ‘ton’.” A soldier shouts out in response, “And what will 1,000 pounds be called, sir?” Washington answers, “Nothing. Because we will have no word for that.” He goes on to tell the confused soldiers that we will measure liquids in liters and milliliters, but “not all liquids, only soda, wine, and alcohol” while for “milk and paint, we will use gallons, pints, and quarts, God willing.”

The skit pokes fun at everything from the seemingly random number of feet and yards in a mile to the apparently arbitrary placement of important temperatures on the Fahrenheit scale. It’s a must-watch that’s sure to have you laughing, but even more than that, it makes you think. Why did the U.S. seem to buck the trend that the rest of the world followed and end up with such a unique hodgepodge of measurements?

I’m currently reading General Chemistry by Linus Pauling, so I happened to learn just a week or so ago why Fahrenheit is the way it is. The answer was quite interesting. I imagine that an exploration of the rest will reap similarly fascinating results, so let’s go over how each came about and why they’re still in use to this day.

Fahrenheit

Most rational people seem to think that the Celsius scale makes a lot more sense than what we use in the U.S. After all, that way of measuring temperature has freezing right at 0° and boiling at 100°. Whereas freezing in Fahrenheit is at 32° and boiling is at 212°. Even as an American, I find ours to be so random that, while I remembered it off the top of my head for Celsius, I had to google it to be sure about the boiling point for Fahrenheit.

Well, Daniel Gabriel Fahrenheit, the inventor of the scale bearing his name, also had the idea to anchor the scale to a well-known physical phenomena, like boiling or freezing, but he chose one that was more anthropocentric. He decided to make 100° the temperature of the human body. He also made 0° the lowest temperature he could obtain, which he reached by mixing equal amounts of snow and ammonium chloride, so it ultimately wasn’t as arbitrary as it seems.

You might be asking yourself here, why is the temperature for the human body we use today 98.6° if he intended to set it at 100°? Believe it or not, it’s theorized that he may have had a fever while calibrating the scale. Seemingly by pure accident, his anchor got moved to 1.4° off. And why have we stuck with it? Well, there are some pros to the Fahrenheit system.

First, it was the international standard at the time. The United States Constitution, in section 8 of Article I, actually specifically gives the power to “fix the standards of weights and measures” to Congress. Some of the Founding Fathers, including Jefferson, actually considered using the then newly formed Celsius scale but chose instead to stick with the “British Imperial System” of measurement.

Second, as Fahrenheit has 180° between freezing and boiling to Celsius’s mere 100°, and it has been shown that humans can feel the difference in one degree of temperature on the Fahrenheit scale, the former is actually more precise. Moreover, for temperate latitudes, it actually fits the weather better, with a cold winter day tending to go around 0° and a hot summer day shifting up to around 100°.

Nonetheless, there have been attempts in the past to change over to the metric system for temperature, and all other basic units of measurement. However, after the start of the Industrial Revolution, such efforts received overwhelming resistance from both big businesses and American citizens in general, as they didn’t want to expend the time and money it would take to change all the machinery.

Inches, feet, yards, and miles

Well, where does the measurement of a “foot” come from? You may have guessed it. It was originally just the length of a person’s actual feet — the ones we use to walk. This was used in the Chinese, Greek, Roman, English, and French systems, but since people are different sizes it was the cause of some confusion and would differ in length from country to country and city to city. For example, the standard Greek foot was roughly 11.9 inches, while the Egyptian foot was just short of that, at 11.8 inches.

In one of the first instances of putting an official standard of measurement in place, Henry I of England passed a law making his foot the standard, and that’s how we continue to measure things in the U.S. today — by a dead king’s foot.

Still, even if that’s pretty random, why not make something like the mile an easy-to-remember number of feet? It’s currently 5,280 feet in a mile. Why not at least give us 5,300?

The answer is because the mile actually originated from the Roman mille passus, which was 5,000 Roman feet. Such a nice round number! In 1592, the English Parliament standardized the mile but against the “furlong,” which is 660 feet. It was eight furlongs to a mile, resulting in the 5,280 feet in a mile as we have it today.

Inches are, of course, one-twelfth of a foot, but they were also associated with body measurements. The inch was first standardized by King David I of Scotland in 1150. He defined it as the average breadth of a man’s thumb at the base of the nail. In common practice, to get a more accurate measure, they would take the measure of three men’s thumbs, add them together, and then divide by three to get an average.

In keeping with the rest, a yard was originally the length of a man’s girdle or belt. However, Henry I standardized that too, by using the distance from his nose to the thumb of his fully extended arm. This happened to be 36 inches, giving us the ratio of three feet to one yard.

Pints, gallons, pounds, and tons

Fortunately, our units for measuring liquids have no relationship to the human body, as that could get really gross really fast. Instead, they owe their size to wine and beer, which were traditionally measured in gallons. However, there was not initially just one size for the gallon. The wine gallon, or Queen Anne’s gallon, was 231 cubic inches. The ale gallon had 282 cubic inches. There was also eventually a corn gallon, or Winchester gallon, measuring out at about 268.8 cubic inches.

A pint is simply 1/8th of a gallon. Yet, with there being a variety of sizes for the gallon, there were just as many pints, which is also true for the half-gallon, quart, and half-pint. A ton derives its name from the tun, which was a cask of the largest size, and used for measuring large quantities of honey, oil, and wine. It would contain a volume between 175 and 213 imperial gallons and tended to weigh about 2,000 lbs.

Take note of the abbreviation for pounds, which was the last word of the preceding paragraph. Why in the world is the word “pound” abbreviated in such a way that none of the three letters making up the abbreviated form are found in the extended form of the word? This is because the pound is derived from the Roman libra, which was an ancient unit of weight used in trade at the time. The word, “libra”, is the source of the abbreviation “lb”.

Dozen

Let’s close out the article with one last oddity in the American system, which is calling 12 of something a “dozen.” This seems to be an ancient practice going all the way back to the Mesopotamians and the duodecimal system they used. This was a system of counting using base 12, instead of the base 10 decimal system we’re all used to today. They likely chose 12 because mathematicians of the time had already recognized that there are about 12 lunar cycles in a year. It’s also believed that it correlated with the bones in the fingers (phalanges) on one hand and was, therefore, a convenient way for counting — just as our decimal system uses base 10 because of our 10 fingers.

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An interesting piece of history is how we got the “baker’s dozen,” which is 13 of something. Medieval England had very strict laws governing the price of bread. Bread was to be priced in a way that correlated with the wheat used to make it. If bakers were found to be overcharging, they would be flogged or beaten as punishment. Afraid of making a mistake, accidentally shorting the customer, and facing these serious penalties as a result, many of them took to just throwing in an extra loaf. Thus, we have the “baker’s dozen”, which exceeds a traditional dozen by one.

Conclusion

The history of measurements is a fascinating one. It’s difficult to imagine people getting by with such makeshift measures for so long. However, when you don’t need the mechanical precision that is necessary to keep modern technology functioning without mishap, it’s easier to understand how rough approximations were able to suffice.

The history of why the U.S. still uses these measurements is a little less rich. We were late to the game, and it’s kind of too late to make a change now. Any attempt to switch over would cost a massive amount of time and money, temporarily hindering the functioning of just about every household and business in ways either small or large. I guess all we can do now is continue to laugh at the oddity of it all — hopefully aided with more skits of Nate Bargatze in his role as a measurement-obsessed Washington.