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"Cormullion," used under Creative Commons license via Wikimedia
"Cormullion," used under Creative Commons license via Wikimedia

Decimal Time: How the French Made a 10-Hour Day

"Cormullion," used under Creative Commons license via Wikimedia
"Cormullion," used under Creative Commons license via Wikimedia

Everybody knows that there are 24 hours in a day, 60 minutes in an hour, and 60 seconds in minute.* But in 1793, the French smashed the old clock in favor of French Revolutionary Time: a 10-hour day, with 100 minutes per hour, and 100 seconds per minute. This thoroughly modern system had a few practical benefits, chief among them being a simplified way to do time-related math: if we want to know when a day is 70% complete, decimal time simply says "at the end of the seventh hour," whereas standard time requires us to say "at 16 hours, 48 minutes." French Revolutionary Time was a more elegant solution to that math problem. The trick was that every living person already had a well-established way to tell time, and old habits die hard.

Noon is Now at 5

French Revolutionary Time officially began on November 24, 1793 although conceptual work around the system had been going on since the 1750s. The French manufactured clocks and watches showing both decimal time and standard time on their faces (allowing for conversion and confusion). These clock faces were spectacularly weird. Here's one -- see if you can figure out when primetime TV starts:

Decimal clock photo by "Cormullion," used under Creative Commons license via Wikimedia

The system proved unpopular. People were unfamiliar with switching systems of time, and there were few practical reasons for non-mathematicians to change how they told time. (The same could not be said of the metric system of weights and measurements, which helped to standardize commerce; weights and measurements often differed in neighboring countries, but clocks generally did not.) Furthermore, replacing every clock and watch in the country was a spendy proposition. The French officially stopped using decimal time after just 17 months -- French Revolutionary Time became non-mandatory starting on April 7, 1795. This didn't stop some areas of the country from continuing to observe decimal time, and a few decimal clocks remained in use for years afterwards, presumably leading to many missed appointments.

Other Attempts at Decimal Time

The French tried again in 1897, when the Commission de décimalisation du temps proposed a 24-hour day with 100-minute hours, again with 100 seconds per minute. This proposal was scrapped in 1900.

And then of course there's the Stardate, a pseudo-decimal system of date measurement used in Star Trek. Unsurprisingly, the Stardate started out being supremely imprecise and was just supposed to sound futuristic; here's a snippet from the Star Trek Guide for teleplay writers on the original series:

We invented "Stardate" to avoid continually mentioning Star Trek's century (actually, about two hundred years from now), and getting into arguments about whether this or that would have developed by then. Pick any combination of four numbers plus a percentage point, use it as your story's stardate. For example, 1313.5 is twelve o'clock noon of one day and 1314.5 would be noon of the next day. Each percentage point is roughly equivalent to one-tenth of one day. The progression of stardates in your script should remain constant but don't worry about whether or not there is a progression from other scripts. Stardates are a mathematical formula which varies depending on location in the galaxy, velocity of travel, and other factors, can vary widely from episode to episode.

And lest we forget Swiss watchmakers in all of this, Swatch introduced their own bizarro decimal time system in 1998. Called Swatch Internet Time, it divided the day into ".beats" (yes, with a dot) and referred to a particular .beat using the @ symbol (so you might say, "ICQ me at @484 so we can swap some beenz, LOL!"). Each .beat lasted 1 minute and 26.4 seconds and represented 1/1000 of a day. Nope, not confusing @all.

See Also

The French Republican Calendar was another attempt by revolutionary France to decimalize everything. It wasn't particularly successful. Also interesting is the Chinese ke, a unit of decimal time.

* = There are actually several exceptions to the 24/60/60 rule, most notably leap seconds, but let's keep it simple.

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Art
5 Things You Might Not Know About Ansel Adams

You probably know Ansel Adams—who was born on February 20, 1902—as the man who helped promote the National Park Service through his magnificent photographs. But there was a lot more to the shutterbug than his iconic, black-and-white vistas. Here are five lesser-known facts about the celebrated photographer.

1. AN EARTHQUAKE LED TO HIS DISTINCTIVE NOSE.

Adams was a four-year-old tot when the 1906 San Francisco earthquake struck his hometown. Although the boy managed to escape injury during the quake itself, an aftershock threw him face-first into a garden wall, breaking his nose. According to a 1979 interview with TIME, Adams said that doctors told his parents that it would be best to fix the nose when the boy matured. He joked, "But of course I never did mature, so I still have the nose." The nose became Adams' most striking physical feature. His buddy Cedric Wright liked to refer to Adams' honker as his "earthquake nose.

2. HE ALMOST BECAME A PIANIST.

Adams was an energetic, inattentive student, and that trait coupled with a possible case of dyslexia earned him the heave-ho from private schools. It was clear, however, that he was a sharp boy—when motivated.

When Adams was just 12 years old, he taught himself to play the piano and read music, and he quickly showed a great aptitude for it. For nearly a dozen years, Adams focused intensely on his piano training. He was still playful—he would end performances by jumping up and sitting on his piano—but he took his musical education seriously. Adams ultimately devoted over a decade to his study, but he eventually came to the realization that his hands simply weren't big enough for him to become a professional concert pianist. He decided to leave the keys for the camera after meeting photographer Paul Strand, much to his family's dismay.

3. HE HELPED CREATE A NATIONAL PARK.

If you've ever enjoyed Kings Canyon National Park in California, tip your cap to Adams. In the 1930s Adams took a series of photographs that eventually became the book Sierra Nevada: The John Muir Trail. When Adams sent a copy to Secretary of the Interior Harold Ickes, the cabinet member showed it to Franklin Roosevelt. The photographs so delighted FDR that he wouldn't give the book back to Ickes. Adams sent Ickes a replacement copy, and FDR kept his with him in the White House.

After a few years, Ickes, Adams, and the Sierra Club successfully convinced Roosevelt to make Kings Canyon a national park in 1940. Roosevelt's designation specifically provided that the park be left totally undeveloped and roadless, so the only way FDR himself would ever experience it was through Adams' lenses.

4. HE WELCOMED COMMERCIAL ASSIGNMENTS.

While many of his contemporary fine art photographers shunned commercial assignments as crass or materialistic, Adams went out of his way to find paying gigs. If a company needed a camera for hire, Adams would generally show up, and as a result, he had some unlikely clients. According to The Ansel Adams Gallery, he snapped shots for everyone from IBM to AT&T to women's colleges to a dried fruit company. All of this commercial print work dismayed Adams's mentor Alfred Stieglitz and even worried Adams when he couldn't find time to work on his own projects. It did, however, keep the lights on.

5. HE AND GEORGIA O'KEEFFE WERE FRIENDS.

Adams and legendary painter O'Keeffe were pals and occasional traveling buddies who found common ground despite their very different artistic approaches. They met through their mutual friend/mentor Stieglitz—who eventually became O'Keeffe's husband—and became friends who traveled throughout the Southwest together during the 1930s. O'Keeffe would paint while Adams took photographs.

These journeys together led to some of the artists' best-known work, like Adams' portrait of O'Keeffe and a wrangler named Orville Cox, and while both artists revered nature and the American Southwest, Adams considered O'Keeffe the master when it came to capturing the area. 

“The Southwest is O’Keeffe’s land,” he wrote. “No one else has extracted from it such a style and color, or has revealed the essential forms so beautifully as she has in her paintings.”

The two remained close throughout their lives. Adams would visit O'Keeffe's ranch, and the two wrote to each other until Adams' death in 1984.

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presidents
George Washington’s Incredible Hair Routine

America's Founding Fathers had some truly defining locks, but we tend to think of those well-coiffed white curls—with their black ribbon hair ties and perfectly-managed frizz—as being wigs. Not so in the case of the main man himself, George Washington.

As Robert Krulwich reported at National Geographic, a 2010 biography on our first president—Washington: A Life, by Ron Chernow—reveals that the man “never wore a wig.” In fact, his signature style was simply the result of an elaborately constructed coiffure that far surpasses most morning hair routines, and even some “fancy” hair routines.

The style Washington was sporting was actually a tough look for his day. In the late 18th century, such a hairdo would have been worn by military men.

While the hair itself was all real, the color was not. Washington’s true hue was a reddish brown color, which he powdered in a fashion that’s truly delightful to imagine. George would (likely) don a powdering robe, dip a puff made of silk strips into his powder of choice (there are a few options for what he might have used), bend his head over, and shake the puff out over his scalp in a big cloud.

To achieve the actual ‘do, Washington kept his hair long and would then pull it back into a tight braid or simply tie it at the back. This helped to showcase the forehead, which was very in vogue at the time. On occasion, he—or an attendant—would bunch the slack into a black silk bag at the nape of the neck, perhaps to help protect his clothing from the powder. Then he would fluff the hair on each side of his head to make “wings” and secure the look with pomade or good old natural oils.

To get a better sense of the play-by-play, check out the awesome illustrations by Wendy MacNaughton that accompany Krulwich’s post.

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