Tag Archives: Royal Navy

Mister Midshipman Hornblower

C.S. Forester’s character, the 19th-century British Royal Navy officer Horatio Hornblower excelled at navigation because he was a math whiz. This got him in trouble as a young midshipman when he showed up a big dumb bully who couldn’t figure out how to work a sextant. https://hornblower.fandom.com/wiki/Sextant
A must-read—https://www.goodreads.com/book/show/84748.Mr_Midshipman_Hornblower

So long, and thanks for all the longitude

After 19 years of tinkering John Harrison finally worked all the bugs out of his time-piece, the marine chronometer. To prove its reliability, he took it on a voyage from England to Jamaica.

“Harrison conducted a round-trip test at sea from Britain to Jamaica through the Caribbean via the Atlantic from 1761 to 1762. The watch lost only 5.1 seconds in 81 days, reaching the level of accuracy required to receive a £20,000 reward.

But just then a rival named Nevil Maskelyne, the head of the Greenwich Observatory and a member of the Commissioners for the Discovery of the Longitude, was vying to receive the same award for his astronomical theory. Maskelyne refused to recognize Harrison’s success. To Harrison’s chagrin, he was granted only a few thousand pounds.”

Well, how do you like that? This is why Maskelyne is always cast as the villain in this story. Seems like a conflict of interest to be on the Longitude Board if you’re also a competitor for the prize. It would be quite a while before Harrison finally got his reward—and that was only because King George III* stepped in to make the Board pay up.

My pal Kathryn Lasky wrote an award-winning book about John Harrison’s story, The Man Who Made Time Travel:

Kathryn and I worked on Two Bad Pilgrims together. https://www.kathrynlasky.com/books/book/two-bad-pilgrims

* George III ruled Great Britain during the American Revolution. He was an enthusiastic friend to the Royal Navy. It was George who decreed that his sailors could toast the king’s health sitting down, because the deck-beams in the wardroom (officers’ dining room) were so low you’d likely crack your head if you stood.

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A dumbbell idea

The problem with clocks in the 1700s: the ship’s rocking messed up a clock’s pendulum movement; the salty sea air corroded the metal gears; changes in temperature and humidity made metal clock parts expand & contract. All these things made a clock inaccurate—it was too slow or too fast.

Harrison came up with some innovative ideas to counter-act these problems. The first one was a dumbbell-style of pendulum. Instead of a rod with a weight at the bottom swinging from an axis, Harrison put the axis in the middle of 2 rods with weights at top and bottom—then he connected them with springs so they would keep moving back and forth no matter how the ship bounced around.

Standard-issue pendulum at the left; Harrison’s dumbbell movement at the right.

Start at 1:00—

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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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Lunar distancing

Okay, let’s say you’re in a rowboat at night with some friends—and you haven’t seen land for a while. You’re LOST. Nobody’s getting a signal on their cellphones, so you don’t know where you are. The strange old lady at the boat rental place left nothing but a weird navigational device; a map; and a book of star charts in the boat’s locker. Your friends are getting panicky and start blubbering. What do you do?

Because you’re a devoted reader of The Western Civ User’s Guide to Time and Space, you know exactly what to do. You tell your pals to stop their noise so you can concentrate. It’s a clear moonlit night, so you can see the moon, stars, and the horizon. You pick up the lovely brass sextant and set its sights on the moon—and a star, how about Regulus, just there to the left? You measure the altitude (how high above the horizon) of the moon; the altitude of Regulus; and the distance between them. You figure the angle of the 2 lines from you to the moon and you to Regulus. You do this measuring not in feet or miles but in degrees.

From the moon’s altitude you know what time it is (http://www.astrotulsa.com/page.aspx?pageid=27, scroll down)—and your latitude, too (http://www.lewis-clark.org/article/1268). Knowing the distance from the moon to Regulus, you pick up the book of star charts and find that lunar distance for your local time. Run your finger down the chart to find what time it is in Greenwich, England where it’s zero degrees longitude. The difference in time will tell you your longitude (15° for every hour, 1° for every 4 minutes). Find your latitude and longitude on the map and start rowing home. You don’t even need a compass—you keep Polaris, the North Star, above your right knee as you row.

You get safely back to land! Your friends can’t believe you saved the day with that stupid book. The lady at the boat rental gives you a wink and you all go home to bed.

This is how Nevil Maskelyne proposed finding your position while at sea.

I haven’t read these, but here’s a short list of books about ocean-going girls: https://books.google.com/books/about/From_Cabin_Boys_to_Captains.html?id=wBDWSAAACAAJ

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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.

Find longitude, win valuable prizes!

In 1714 the British government established the Board of Longitude and held a contest: Who can come up with a system to accurately tell where you are at sea? The Royal Navy disaster on the Isles of Scilly had caused a reaction from the British public—they’d seen their own sailors drowned on the coast of their own country. Whether that disaster was the motive for creating the Board of Longitude may be disputed, but there’s no doubt a better, more accurate system of finding your location at sea needed to be found.

The Longitude Act, ‘An Act for providing a Publick Reward for such Person or Persons as shall discover the Longitude at Sea,’ was passed. The government offered up to £20,000 for a method of finding longitude at sea to within half a degree. That’s a lot of clams!

The Board of Longitude included scientists and astronomers who would judge the quality of any longitude systems that were submitted. One was the Astronomer Royal who worked at the Greenwich (GREN-itch) Observatory. I think if I ever got my career to the point where my job-title was Astronomer Royal I would consider myself to have arrived.

Astronomer Royal John Flamsteed, who also made the first recorded observations of Uranus.


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The Isles of Scilly

I said it would take an awful catastrophe to motivate sailors to find accurate longitude.

At the southwesternmost tip of England is a place called Cornwall. Along its coast is the harbor of Penzance, the home-port of Gilbert & Sullivan’s musical pirates. Off the southwesternmost tip of Cornwall are the Isles of Scilly—hard, treacherous, unforgiving granite rocks that jut straight up out of the Atlantic Ocean.

During a horrible storm on October 22, 1707, not knowing their position (there were differences of opinion among the captains), four Royal Navy ships were wrecked on these islands. 1550 sailors lost their lives—it was one of the worst disasters in British naval history.

Those sailors thought they were far enough south of the rocks to sail east into the English Channel. They were wrong. They struck the rocks, were shipwrecked and drowned. May God rest their souls.

I’ve been joking around here—presenting the problem of longitude in a light-hearted, smart-alecky way. But you see how deadly serious it is not to know your position when you’re in the middle of the ocean during a storm.

Well, what was going to be done about it?


Sir Cloudesley Shovell and the Scilly Naval Disaster of 1707

While looking for info about Scilly, I found this masterful painted sketch of the rocks by Anna Kirk-Smith. I love its wildness. https://www.saatchiart.com/art/Drawing-Sea-Edge-Rocks-of-Scilly/988141/3626138/view

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Come cheer up, my boys, ’tis to glory we steer

British ship of the line

We watched nations compete for the best ocean trade routes. Trade with the Far East, India and the New World was how nations made money, how they kept themselves alive. And so they protected their trade routes and created monopolies—exclusive ownership of a market. Venice, Spain, Portugal and then England built ships mounted with cannon to enforce their ownership of trade routes. Ship design grew from the charming little caravel to the mighty ship of the line. These military ships, together, are called a navy. By the end of the 1600s naval power was the big instrument for building empires.

Heart of Oak

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