Harrison’s Clocks
by John
I have seen these famous clocks in the past, before I had read “Longitude”. But now, knowing how incredibly important it was to have an accurate marine chronometer, and knowing the story of how a carpenter, John Harrison, invented, developed, and made the world’s first accurate marine chronometers in the early eighteenth century, I could not miss the opportunity to revisit the Royal Greenwich Observatory, on my visit to Greenwich.
Amazingly, 3 of the 4 clocks are still working accurately. I am not sure why the final, wonderful, Harrison 4 is not working. That is the clock which finally made Harrison a wealthy person.
Harrison 1. Intriguing mechanism, but had wooden gears and other wooden parts, and was not quite accurate enough. It weighs 30kg.
Harrison 3. More compact. All brass gears and shafts. No bobbing pendulums. Still heavy, but a bit less bulky. 19 years in development, and still not up to scratch according to Harrison, who was probably a bit OCD. One aspect which really impressed me with these clocks, was the incredibly high standard of metal work and metal finishing.
Harrison 4. Like a big pocket watch. But won him the prize, and made him a very rich man. Unfortunately Harrison died not too long after winning the prize.
John Harrison with his final chronometer. And a picture behind him of number 2 (I think). (Actually H3)
The board which was determining whether his chronometer (number 4) was worthy, dallied and prevaricated to avoid paying Harrison the 20,000 pound prize. Fortunately, King George 2 intervened and took up Harrison’s cause, and eventually he was paid a total of 23,000 pounds, which made him the equivalent of a modern multi millionaire.
His Harrison 4 kept time on a moving, rocking ship, within 1 minute in 90 days, which was a quantum leap in accuracy, and resulted in vastly more accurate navigation, and saving sailors lives.
“Longitude” is an excellent read. And seeing these timepieces in reality, was an experience which I will not forget.
johnsmachines 
Not about clocks but about your book reviewing skill. I am much impressed. And I’d be delighted if you would review mine. https://www.iuniverse.com/bookstore/bookdetail. Be happy to reimburse your kindle charge if you would post review to amazon.com – https://www.amazon.com/School-Sun-Tzu-Winning-Empires-ebook/dp/B079K3TDYR/ref=tmm_kin_swatch_0?_encoding=UTF8&qid=&sr=
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Hi, I tried but page not found. Is it correct?
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Works for me. If you can’t connect – it’s school of sun tzu (kindle edition) on amazon
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Oh – that’s the reviews page. Here’s the book:
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“dallied and prevaricated to avoid paying Harrison the 20,000 pound prize”
This is so common. Inventors getting screwed. Large German co offered €100,000 last year for each of best EV motor, controller, & eAxle. I thought thanks, I could do with that. Sent my entry in, same day got a reply ‘Brilliant, Stuart, we’ll check the other entries & get back to you’
A week later it was ‘Bad luck, Stuart, you didn’t win (Note name change) ‘eAxis’ div. So I asked who won. ‘Freudenberg KG won the ‘eAxis’ div, with new ideas for cooling an electric motor’
Smoke still coming out my ears.
Just more German auto industry fraud.
Stuart
Intellectual Property Rightful Owners Action Group. IPROAG
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Oh dear! Where on Earth did you get the idea that Harrison’s H1 clock has wooden gears and other wooden parts! John Harrison did build a wooden clock, but H1 is all brass.
The photo that you have labelled Harrison 4 is NOT H4, it’s not even one of his clocks! It is a chronometer made by Margetts of London c1795.
The portrait of John Harrison shows him holding a watch made by watchmaker John Jeffries to Harrison’s design, the clock behind him in the portrait is H3 not H2.
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Hi Robin,
The mainspring gear, and I think six others in the train, in H1 are made of wood. Lignum vitae.
I will change the photo of H4. Wrong photo slipped in. Yet to double check the portrait details but will correct those if necessary.
Must have had a red too many when I wrote that post. Thanks for the feedback. John
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