Beware the Ides of March!

Apologies to the JUMBLE® guys: Henri Arnold, David L. Hoyt and Jeff Knurek!

https://www.historyextra.com/period/roman/what-ides-of-march-meaning-caesar-death/

Et Tu, Brute?

A really long trip and no egg roll

What just happened? Columbus thought he would get to China (the ‘Indies’) by traveling west. He was right, as far as his theory went. But Columbus had no idea there would be two king-sized continents—North and South America—standing in his way. He and his crew spent the next 5 months exploring the islands Cuba and Hispaniola before they went home to Spain.

Columbus was disappointed. He really wanted to reach China. He considered himself a failure for not accomplishing that goal. What he didn’t realize was that the Americas, with all their natural resources (gold, in particular), would become more valuable to Spain than China ever could be.

https://www.gilderlehrman.org/blog/columbus-lands-america-day-1492
http://www.eyewitnesstohistory.com/columbus.htm

Land, ho!

Even so, after two months the crew were unhappy and ready to turn around. Columbus said, “Okay, bambini. Give me two more days. If we don’t see land in two days, we’ll turn around and go home.” Luckily for Columbus, the next day they saw birds, and some branches floating around—the kind of stuff you see when you get close to land. Sure enough on October 12th, 1492 the Nina, the Pinta and the Santa Maria bumped into the island of Guanahani—which Columbus called San Salvador. It’s part of a group of islands called the Bahamas, off of Florida.

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Are we there yet?

Columbus had a feeling his crew would start getting antsy, so he kept 2 logs. A captain’s log is a daily record of data: ship’s speeds, changes in course, weather and other news. In one secret log Columbus was honest—he wrote the actual distances they had come each day (as far as he could tell). In the second log, Columbus wrote that they hadn’t come very far at all. He added some potty stops they hadn’t taken. That’s the log he showed his crew. He wanted them to not be upset that the voyage was taking so long.

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Meanwhile, on the Atlantic Ocean…

Christopher Columbus’ crews are getting worried. If you’ve ever traveled to a new place, you know how they were feeling—”Are we there yet? How much longer?” Remember: those guys were probably okay with the idea that the Earth is round, but they didn’t know it for sure. After a couple of months, maybe they’re starting to think traveling west to reach the east isn’t such a hot idea after all.

Sailors in those days didn’t have an accurate way of knowing how far east or west they were. A compass can tell you which direction you’re traveling. An astrolabe will tell you how far north or south you are and what time it is. Casting a log will give you a rough idea of how far you’ve traveled. There was simply no way for Columbus and his crew to know exactly how far west they were.

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The amazing fantastic clock of Piazza San Marco

In 1493, the Venetian Republic commissioned the clockmaker Giovan Paolo Rainieri, from the town of Reggio Emilia, to design and build a clock. This clock would be big and beautiful and expensive—a tower would be designed and built on Saint Mark’s Plaza to house it. It would face the lagoon and the sea beyond, so the whole world could see how prosperous was Venice.

If you visit Venice you can see the Rainieri clock. Its face is decorated in gold and lapis lazuli (a mineral you make blue out of—blue paint ain’t cheap); the hand tells what hour it is and the current zodiac sign; above the clock is a statue of the Virgin Mary and Baby Jesus (made of gilded copper); twice a year a mechanical angel and three wise men parade in front of Mary and tip their crowns to her; above Mary is the lion of Saint Mark with his paw on the Gospel (the statue of the praying doge isn’t there anymore); and at the top, every hour two bronze giants ring an enormous bell with their hammers.

The entire contraption from top to bottom used a verge and foliot escapement to regulate the gears.

https://www.atlasobscura.com/places/torre-dell-orologio-venice-clock-tower
https://en.wikipedia.org/wiki/St_Mark%27s_Clock

https://en.wikipedia.org/wiki/St_Mark%27s_Clocktower

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Happy Fat Tuesday!

I used to make up these puzzles for my Sunday school class. Apologies to the JUMBLE® guys: Henri Arnold, David L. Hoyt and Jeff Knurek!

Speaking of libraries, I’ll be at the Grove City Community Library this Friday (2/28/20) evening 6:00-7:00 to talk about illustrating kids’ books. If you’re in the neighborhood, please stop by!

How to slow down a clock

How did they do it?

Those medieval clock-designers came up with a system to slow down the unwinding. First, they attached a gear around the drive-shaft that meshed with a couple of other gears. As you saw with Archimedes’ odometer, the ratio of gear sizes and number of teeth-per-gear can control how fast one gear turns another gear.

That still wasn’t slow enough, though. You want a clock to operate for at least 24 hours before you have to wind it again. How can you make that unwinding even slower?

The answer: an invention called an escapement. An escapement is a mechanical device that interferes with the gear. It actually stops the gear’s movement for a fraction of a second, then lets go for a fraction of a second, stops it, lets go, stops it, lets go, stops it, lets go. The first escapement was called the verge and foliot. The verge is a second shaft (not the drive-shaft) with two paddles, or pallets, set at 90 degrees to each other. These pallets interact with a saw-toothed gear which is powered by the drive shaft. As the drive-shaft turns the saw-toothed gear, one pallet stops the gear for a moment until the other pallet is pushed aside.

This stop-and-let-go motion is controlled even further by a bar at the top of the verge shaft, called the foliot. The foliot has a weight hung on each end so that inertia (the weights’ unwillingness to move) slows down oscillation of the verge-shaft. You can control how fast the foliot swings back and forth by moving the weights closer or farther from the center.

https://aapt.scitation.org/doi/10.1119/1.3479712




https://www.mpoweruk.com/timekeepers.htm
https://www.uh.edu/engines/epi1506.htm

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Mechanical clocks

Sometime in the 1200s mechanical clocks began being designed and built. When I say mechanical, I mean there are several moving parts in the design. We’ve already seen sundials and water clocks and hourglasses. Water clocks and hourglasses use the release of energy to tell time, as water or sand run out of one container into another. The mechanical clock is different—it uses the release of energy to make it run but has a system of gears and stops to control that energy.

Like those older clocks, medieval mechanical clocks use gravity to supply their energy. A weight is tied to a long rope that is wound around a drive-shaft. When you let go of the weight, the rope unwinds and turns the shaft. The drive-shaft has an arrow attached at its end to point to the hour on a circular clock face. So far, so good—but the drive-shaft will turn really fast for a few seconds, the arrow will whiz around the clock face and then you’d have to wind the rope around again. You still wouldn’t know what time it is. What you need for a clock is a slo-o-o-ow release of energy. How can you slow down the unwinding of that rope?

Sailing the ocean blue

As you know if you’ve been loyally reading this blog, silk and spices from Asia had become big business in Europe. European merchants who wanted to trade in the far East were finding overland routes through the MidEast and Asia too dangerous, or taxed to unprofitability, or closed off completely by the Ottoman Empire. In fact, the Ottomans were doing their best to expand their empire to include Europe.

The Venetians had a monopoly on the sea-routes that they protected with their navy. Other European cities who wanted to do business with the far East were shut out. They had compasses and maps and ships but had no way to get to the East.

Or did they?

Christopher Columbus was a sailor, chartmaker and trader from Genoa, Italy. He’d done some trading along the west coast of Africa. Columbus had studied Eratosthenes and reasoned that if Earth were round, he could travel west to reach the far East. To do that, he needed ships, money and royal patronage—the blessing of a king or queen.

King Ferdinand II and Queen Isabella I ruled the cities of Aragon, Castile, and Leon in Spain. Spain had been part of the sultanate, the Ottoman Empire, for nearly eight centuries. Ferdinand and Isabella wanted to reassert Christian control over their country—they had succeeded with military force early in 1492 at the Battle of Granada. Another way to take control might be to open up trade with the far East by working around the Ottomans. After a few interviews, Columbus persuaded Ferdinand and Isabella that he could take the back way around the globe to reach the East.

They finally gave him the green light and in ad 1492 Christopher Columbus began his voyage to the East Indies with the ships Nina, Pinta & Santa Maria.

The lovely little caravel—a Portuguese-designed ship like the ones Columbus used on his voyage

https://www.britannica.com/biography/Christopher-Columbus
https://www.britannica.com/place/Spain/The-conquest-of-Granada
https://www.newworldencyclopedia.org/entry/Fall_of_Granada
https://en.wikipedia.org/wiki/Caravel

If you like your history served with gorgeous illustrations, get your hands on Bjorn Langstrom’s book about Columbus. Mr Langstrom has written and illustrated 3 books about ships that I know of. See if your library has this one.

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