Why Do Coins Have Ridges?

iStock/tweetyclaw
iStock/tweetyclaw

The stylish rims you might have noticed on U.S. dimes, quarters, half dollars and some dollar coins are called reeded edges. They’ve been on American currency almost since day one as a way of keeping people honest.

The United States Mint built its first minting facility in Philadelphia in 1792. The following March, it produced its first batch of circulating coins - 11,178 copper pennies. The silver coins that soon followed were linked to a silver standard, per the 1792 Mint and Coinage Act. This meant the “major” coins were at least partially made up of the precious metal (the first dollar coin, from 1794, was 89.25% silver and 10.75% copper). Silver dollars contained about a dollar’s worth of silver, give or take, and the others – half dollars, quarters and dimes – had a proportionate metallic content and size. Half-dollar coins contained ½ the amount of silver as a dollar and were half the size, quarters had ¼ the amount of silver, and so on.

Reeded edges served a two-fold security purpose for silver coins. One, they added an additional, intricate element to the coins that made them more difficult to counterfeit. Two, they prevented fraud.

How do ridges prevent fraud?

For as long as coins have been made from precious metal, a fairly common way to make a quick, ill-gotten buck was coin clipping. Clippers would shave off a tiny amount of metal all the way around the rims of a bunch of coins, collect the shavings, then sell them. Working carefully, a coin clipper could trim enough off of coins to make a nice profit, but not so much as to make them noticeably lighter or smaller. A clipper could then still go out and spend his devalued coins as if they were unaltered. Reeded edges ruined this scheme, since a shaved edge would be immediately obvious and alert anyone who received one that something was wrong.

Why don't nickels and pennies have reeded edges? Nickels and pennies are mainly composed of inexpensive metals, so the chances that they would be tampered with are low.

Before their adoption by the U.S. Mint, reeded edges were also used in the UK. When the physicist Isaac Newton became warden of the Royal Mint in 1696, he used reeded edges, among other means, to combat clippers and counterfeiters. Other European coins from as far back as the early 1500s also feature reeded edges.

Wait, are people still clipping coins?

Due to the abandonment of the silver standard and a worldwide silver shortage in the mid-20th century, the Coinage Act of 1965 authorized a change in the composition of dimes, quarters, and half-dollars, gradually shrinking their silver content down to the present-day 0%. Coin clipping is no longer a problem, but reeded edges are still around, a centuries-old security measure hanging on in an age where people pay for things with their smart phones instead of digging out pocket change. The tenacity is admirable. But why are they still there?

Coins are made by stamping coin blanks with a metal tool called a die. The die is engraved with the negative of a coin’s design, and the positive image is transferred to the coin when stamped. When the coins are struck, a part of the die called the collar holds the blank in place and applies the edge. When the silverless coins were first produced, the government didn’t see any need to make or buy expensive new dies or collars. Keeping the reeding wouldn’t hurt anyone, they figured, so the new coins were struck from the same old dies as the old ones, and reeding continued to be used as a matter of tradition and backwards-compatibility. Newer coins with updated designs (state quarters, new portraits) also have reeded edges. The design element lived to see another day on the new dies because reeding is useful for distinguishing coins by feel as well as appearance, making them more user-friendly for the visually impaired.

I can't stand the suspense. How many ridges are on my quarter?

If you gather up a bunch of coins, you'll see that not all reeded edges are created equal. The number and size of reeds on coins is not dictated by law, so individual U.S. Mints were long free to make their reeds to their own in-house specifications, leading to distinct style differences between coins from different mints and eras. Rare dimes from the now-defunct Carson City Mint’s 1871-74 runs, for example, have 89 broad, widely spaced reeds. The dimes made by the Philadelphia Mint in those same years have 113 thin, tightly-spaced reeds. 

Things are a little more standardized now and the Mint lists its reeding specifications as follows: dimes, 118; quarters, 119; half dollars, 150; dollar, 198; Susan B. Anthony dollar, 133.

Why is Friday the 13th Considered Unlucky?

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iStock

Today, people around the globe will feel uneasy about getting out of bed, leaving their homes, or going about their normal daily routines, all because of a superstition. These unfortunate folks suffer from paraskavedekatriaphobia, a common neurosis familiar to us all: the fear of Friday the 13th. But just where did this superstitious association come from, and how did it catch on?

The truth is that no one is absolutely sure where the idea that Friday the 13th is unlucky originated. Donald Dossey, the founder of the Stress Management Center and Phobia Institute in Asheville, North Carolina, suspects the fear can be traced back to a Norse myth about 12 gods who had a dinner at Valhalla—the fabled hall where legendary Norse heroes feasted for eternity after they died—that was interrupted by a 13th guest, the evil and mischievous god Loki.

According to legend, Loki tricked Höðr (the blind god of winter and son of Odin, the supreme god in Norse mythology) into shooting his brother Baldr (the benevolent god of summer who was also a son of Odin) with a magical spear tipped with mistletoe—the only substance that could defeat him. Thus the number 13 was branded as unlucky because of the ominous period of mourning following the loss of such powerful gods by this unwanted 13th guest.

For whatever reason, among many cultures, the number 12 emerged throughout history as a "complete" number: There are 12 months in a year, 12 signs of the zodiac, 12 Gods of Olympus, 12 sons of Odin, 12 labors of Hercules, 12 Jyotirlingas or Hindu shrines where Shiva is worshipped, 12 successors of Muhammad in Shia Islam, and 12 tribes of Israel. In Christianity, Jesus was betrayed by one of his 12 Apostles—Judas—who was the 13th guest to arrive for the Last Supper. Surpassing the number 12 ostensibly unbalances the ideal nature of things; because it is seen as irregular and disrespectful of a sense of perfection, the number 13 bears the stigma of misfortune and bad luck we know today.

WHY FRIDAY?

Friday joins in the mix mostly because all of the early accounts of Jesus’s crucifixion agree that it took place on Friday—the standard day for crucifixions in Rome. As Chaucer noted in The Canterbury Tales, "And on a Friday fell all this mischance." Yet perpetuating Friday as an unlucky day in America came from the late 19th-century American tradition of holding all executions on Fridays; Friday the 13th became the unluckiest of days simply because it combined two distinct superstitions into one. According to the Oxford University Press Dictionary of Superstitions, the first reference to Friday the 13th itself wasn’t until 1913. (So despite actually occurring on Friday, October 13, 1307, the popular notion that the Friday the 13th stigma comes from the date on which the famed order of the Knights Templar were wiped out by King Philip of France is just a coincidence.)

The repercussions of these phobias reverberated through American culture, particularly in the 20th century. Most skyscrapers and hotels lack a 13th floor, which specifically comes from the tendency in the early 1900s for buildings in New York City to omit the unlucky number (though the Empire State Building has a 13th floor). Some street addresses also skip from 12 to 14, while airports may skip the 13th gate. Allegedly, the popular Friday the 13th films were so-named just to cash in on this menacing date recognition, not because the filmmakers actually believed the date to be unlucky.

So, is Friday the 13th actually unlucky? Despite centuries of superstitious behavior, it largely seems like psychological mumbo jumbo. One 1993 study seemed to reveal that, statistically speaking, Friday the 13th is unlucky, but the study's authors told LiveScience that though the data was accurate, "the paper was just a bit of fun and not to be taken seriously." Other studies have shown no correlation between things like increased accidents or injuries and Friday the 13th.

And Friday the 13th isn't a big deal in other cultures, which have their own unlucky days: Greeks and Spanish-speaking countries consider Tuesday the 13th to be the unluckiest day, while Italians steer clear of Friday the 17th. So today, try to rest a little easy—Friday the 13th may not be so unlucky after all.

Additional Source: 13: The Story of the World’s Most Popular Superstition.

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Does the Full Moon Really Make People Act Crazy?

iStock.com/voraorn
iStock.com/voraorn

Along with Mercury in retrograde, the full moon is a pretty popular scapegoat for bad luck and bizarre behavior. Encounter someone acting strangely? Blame it on the lunar phases! It's said that crime rates increase and emergency rooms are much busier during the full moon (though a 2004 study debunked this claim). Plus, there's that whole werewolf thing. Why would this be? The reasoning is that the moon, which affects the ocean's tides, probably exerts a similar effect on us, because the human body is made mostly of water.

This belief that the moon influences behavior is so widely held—reportedly, even 80 percent of nurses and 64 percent of doctors think it's true, according to a 1987 paper published in the Journal of Emergency Medicine [PDF]—that in 2012 a team of researchers at Université Laval's School of Psychology in Canada decided to find out if mental illness and the phases of the moon are linked [PDF].

To test the theory, the researchers evaluated 771 patients who visited emergency rooms at two hospitals in Montreal between March 2005 and April 2008. The patients chosen complained of chest pains, which doctors could not determine a medical cause for the pains. Many of the patients suffered from panic attacks, anxiety and mood disorders, or suicidal thoughts.

When the researchers compared the time of the visits to the phases of the moon, they found that there was no link between the incidence of psychological problems and the four lunar phases, with one exception: in the last lunar quarter, anxiety disorders were 32 percent less frequent. "This may be coincidental or due to factors we did not take into account," Dr. Geneviève Belleville, who directed the team of researchers, said. "But one thing is certain: we observed no full-moon or new-moon effect on psychological problems."

So rest easy (or maybe not): If people seem to act crazy during the full moon, their behavior is likely pretty similar during the rest of the lunar cycle as well.

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