Tag Archives: time

Simpler time

Loyal readers of this blog know that as you travel east or west, local time is determined by how far you are from the Prime Meridian. Each degree of longitude means 4 minutes of time difference. Wherever you happened to live in the United States in the 1800s, your town kept local time depending on when the Sun was highest—at noon. Your town’s time might be a few minutes different from the next town to the west or east.

That changed when the railroad connected the country.

Trains must keep to schedules! The boys in the railroad scheduling department didn’t want to pull out a sextant to know when the train would pull into the station in Grand Rapids or Medicine Hat or Lake Tahoe. They needed time to be simpler. So they dreamed up the idea of time zones.

“On November 18, 1883, America’s railroads began using a standard time system involving four time zones, Eastern, Central, Mountain and Pacific.”

That meant everybody in one time zone all kept the same time. If you travel over to the next time zone, you change your watch or clock by one full hour. A time zone represents 15° of longitude only roughly. Mostly it’s the states’ boundaries—not the actual meridian—that determine the split. If the state is too big to conveniently fit into 15 degrees, then county lines are used to define the time zone.

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The big ditch

A passenger barge pulled by a mule or two. The helmsman steers.

The cities on the eastern coast of the United States needed to be connected with the western settlements so that both could do business. One of the first ideas to shorten the trip from New York City to Ohio was the wonderful Erie Canal.

An upstate New York miller named Jesse Hawley suggested digging a long ditch, a canal, from the Hudson River at Albany to the Great Lakes at Buffalo. Even President Jefferson thought it was a crazy idea, but New York Governor Dewitt Clinton liked it and pushed through government funding for construction. For eight years—from 1817 to 1825—crews worked to dig the canal. It was an engineering marvel. How did they figure out how much dirt needed to be moved, or how much of a slice to take out of hill? From what I understand, there was never an accredited engineer on the building site. Back in those days, presumably, a kid’s grade school education included Euclid’s Elements (I’m not kidding. Up until 100 or so years ago Elements was the #2 bestseller after the Bible).

When the canal was done, you could get to the MidWest from New York City in less than half the time of a stagecoach.

“Canal packet boat passengers traveled in relative comfort from Albany to Buffalo in five days—not two weeks in crowded stagecoaches. Freight rates fell 90 percent compared to shipping by ox-drawn wagon. Freight boats carried Midwestern produce from Buffalo to Albany. Most continued on to New York City’s seaport, towed down the Hudson River in fleets behind steam tugboats. Mid-western farmers, loggers, miners, and manufacturers found new access to lucrative far-flung markets.”

This site has a really good video about the canal—https://eriecanalway.org/learn/history-culture

Here’s Bruce Springsteen singing the Erie Canal song—


It’s 2 metals in 1!

This next part is crazy. I don’t know how Harrison dreamed up this idea. I don’t know how it’s even possible. Maybe a reader with experience in welding can help me out.*

Because metal springs are susceptible to temperature changes, which make them less reliable and accurate, Harrison invented the bimetallic strip. It is 2 metals, like steel and brass, welded together.

Did you get that? It’s possible to weld, or fuse, or something, steel and brass now. The watch’s mainspring needs always to be springy. When it’s cold, the spring becomes too stiff. When it’s hot, the spring becomes too loose. Harrison fused two metals together—steel and brass—in a spring. If the steel were too tight, the brass would keep it loose. If the brass were too loose, the steel would tighten it up. This way the spring would keep the same springiness no matter the temperature.

* This weekend I had the pleasure of consulting 2 engineers, my sister’s boyfriend Dave and my nephew Andrew. They tell me with enough heat, two different metals can be fused together. The two metals would be hammered together many times under heat until they were one. Andrew added that it’s only air molecules that keep metals from fusing together in the first place.





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Hot- and cold-running time

After breaking his heart trying to perfect a clock to keep accurate time on the high seas, Harrison refused to give up. He turned instead to perfecting a watch.

No more worrying about pendulums!* Harrison got straight to work on a ship’s timepiece that uses a metal spring and balance wheel. That good ol’ metal spring and balance wheel would do the trick. No problems with a metal spring and balance wheel, no sir.

Well, maybe one small problem. When metal is warm, it expands slightly. When it cools, it contracts. This spring-powered timepiece was expected to be used in both tropical and arctic conditions. The temperature would change the character of the metal, which would make it less reliable, which would make the timepiece less accurate.

Now what?

* Okay, okay, pendula for you Latin nerds.

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Watch works

You remember an escapement is a way of slowly releasing energy that powers a clock. A watch didn’t use a pendulum for its escapement—it used a coiled metal mainspring and balance wheel. You wind the spring tightly and the spring wants to unwind. As it unwinds, its energy is released to oscillate the balance wheel back and forth. As the balance wheel oscillates, it swings a little fork side-to-side which stops and releases a gear. This is the watch’s escapement. No matter how the watch is bounced around, the spring keeps on releasing energy at a steady, reliable pace.

The wound-up spring wants to uncoil, to expand. As it expands, it pushes and turns the balance wheel. But the balance wheel is weighted so it only turns so far and then it swings back. When the balance wheel swings back it tightens the spring again. The wound-up spring wants to uncoil, to expand. As it expands, it pushes and turns the balance wheel. But the balance wheel is weighted so it only turns so far and then it swings back. When the balance wheel swings back it tightens the spring again. (Repeat over and over and over and…)

This beautiful video has French narration but the visuals are self-explanatory: The escapement animation starts at 3:30.

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Keep on trying

With John Harrison’s innovations, his clocks were more precise than any clock had ever been. The bad news was: his clocks still weren’t precise enough to win the Longitude Prize. “The amount awarded under the Act was commensurate with the accuracy of the invention in determining longitude: 10,000 pounds for 1 degree, £15,000 for 2/3 of a degree, and £20,000 for 1/2 of a degree.”

Rather than give up, Harrison tried something different. Instead of designing a precision clock, he turned to designing a precision watch. A watch is an analogue or mechanical (not digital) timekeeping device small enough to carry around with you. You can hold one in your hand. People attached an end of a chain to their watch, attached the other end to a belt loop or button-hole and kept the watch in a pocket.

Random side-note: A pocket-watch and chain play a part in the O. Henry short story, The Gift Of The Magi. https://www.enotes.com/topics/gift-magi Spoiler alert! DON’T unlock the summary until you’ve had the pleasure of reading the story itself.

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The Grasshopper

Since John Harrison was a cabinet-maker, he knew all about constructing things from wood. In fact, the first clocks he built as a young man had all-wood mechanisms. When designing a ship’s clock, he replaced many metal parts with wooden ones. Harrison used an oily wood named Lignum Vitae which didn’t need to be lubricated. Then, he designed a brand-new kind of escapement: the Grasshopper. The Grasshopper escapement worked with way less contact with the clock’s gears, which meant less lubrication was needed.

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The clockmaker

In our last post you saw how to find your location by observing the moon and stars to calculate lunar distance. The object is to know both your local time and prime meridian time, or Greenwich Mean Time. A navigator needs to be an astronomer and a math whiz to use this method.

You may have asked yourself, “Wouldn’t it be easier to keep 2 clocks aboard the ship—one showing Greenwich Mean Time and the other kept to local time?” That’s an excellent question and I’m glad you asked it. In fact, that’s the question John Harrison asked.

John Harrison, English inventor and horologist, 1767.

John Harrison was a cabinet-maker with a side business building and repairing clocks. To win the Longitude Prize, he went for a straightforward solution: build an accurate clock that always, ALWAYS showed precisely the correct time in Greenwich.

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Oh, it’s on

Offering 20,000 pounds back in 1714 was like offering millions of dollars today. Who wouldn’t want to win that longitude prize money? All you had to do was devise a precise method for finding your location on Earth.

The responses didn’t come pouring in overnight. You may have noticed that the big naval disaster on the Scilly Islands happened a whole 7 years before Parliament got around to forming the Longitude Commission. Some serious brainwork—and tinkering—needed to be put in. This was going to take awhile. As mentioned earlier, time/distance/astronomy are interlinked. The people who responded to the Longitude Commission’s offer worked in astronomy and time.

There were 2 main competitors in the race to find longitude: an astronomer and a clockmaker.