Please create an account to participate in the Slashdot moderation system

 


Forgot your password?
Close
typodupeerror
×
Transportation United Kingdom Science Technology

John Harrison: Inventor and Longitude Hero 106

Posted by samzenpus from the all-credit-due dept.
szczys writes: Here's an interesting fact: when at sea you can't establish your longitude without a reliable clock. You can figure out latitude with a sextant, but not longitude. Early clocks used pendulums that don't work on a rocking boat. So in the 1700s the British government offered up £20,000 for a reliable clock that would work at sea. John Harrison designed a really accurate ocean-worthy clock after 31 years of effort and was snubbed for the prize which would be £2.8 Million at today's value. After fighting for the payout for another 36 years he did finally get it at the ripe old age of 80. The methods he used to build this maritime chronometer were core to every wrist and pocket watch through the first third of the 20th Century. One of his timepieces, designated Clock B, was declared by Guinness to be the world's most accurate mechanical clock with a pendulum swinging in free air' more than 250 years after it was designed.
This discussion has been archived. No new comments can be posted.

John Harrison: Inventor and Longitude Hero More

John Harrison: Inventor and Longitude Hero

Comments Filter:

  • Dava Sobel (Score:5, Informative)

    by sillivalley ( 411349 ) <{ten.tsacmoc} {ta} {yellavillis}> on Monday September 28, 2015 @07:16PM (#50616841)
    Please, read Dava Sobel's book, Longitude, about the trials and travails of Harrison -- it's a tremendous read. And if you ever get to the Royal Observatory in Greenwich (England), look at the Harrison models, they are amazing.

    This is a guy who was a Maker -- self taught and more.

    • Re:Dava Sobel (Score:4, Funny)

      by Radical Moderate ( 563286 ) on Monday September 28, 2015 @07:22PM (#50616869)
      There's a movie by the same name, starring Jeremy Irons. Slow, but well worth a watch (heh).

    • Re:Dava Sobel (Score:5, Insightful)

      by Dutch Gun ( 899105 ) on Monday September 28, 2015 @07:24PM (#50616881)

      I never read the book, but watched a really interesting documentary about his lifelong pursuit of that prize. It's really quite fascinating if you have any interest in maritime history.

      It's also a bit sad how he was completely snubbed and denied proper credit for his inventions (in addition to the monetary prize for many years) at the time simply because of his social status (a relatively uneducated craftsman). From what I remember, it literally took the King of England to force the issue after he saw those amazing devices in action, and heard how irrationally stubborn the prize committee was being.

      • he was also fighting a cabal of astronomers who ran things and thought astronomy was the only way to do the job.

        • Yep, that's very true. Still, I have a feeling had he been well-educated or of noble birth, he would have been taken much more seriously, even despite the committee's predilection for an astronomical solution.

    • The website for the Royal Observatory has a couple of pages on maritime time-keeping:

      http://www.rmg.co.uk/whats-on/... [rmg.co.uk]
      http://www.rmg.co.uk/whats-on/... [rmg.co.uk]

    • Re: (Score:3, Informative)

      by TWX ( 665546 )

      Please, read Dava Sobel's book, Longitude, about the trials and travails of Harrison -- it's a tremendous read. And if you ever get to the Royal Observatory in Greenwich (England), look at the Harrison models, they are amazing. This is a guy who was a Maker -- self taught and more.

      They aren't the Harrison models, they're the actual clocks he built. What I found interesting is that the final winning device, the H4, is arguably a really large pocket watch rather than a traditional clock, and was the first device to be unaffected by the motions of the vessel in the water, which were what caused all previous models to fail when they otherwise worked on land.

      This guy wasn't a Maker, he actually knew how to do things and how to use hand tools to achieve his goals. He was an inventor t

      • Re: (Score:1)

        by Anonymous Coward

        For those in the Northeast, the actual H4 is on display in a special exhibit at the Mystic Seaport along with a number of other interesting artifacts from the development of a reliable system of navigation.

      • This guy wasn't a Maker, he actually knew how to do things and how to use hand tools to achieve his goals.

        Aaah excellent more maker hate from randos on the internet. I don't get the sheer level of vitriol aimed at people who instead of sitting on their arses watching TV or whining on the internet actually get up and do something with their time. Jealousy, perhaps?

        • Re:Dava Sobel (Score:4, Interesting)

          by AthanasiusKircher ( 1333179 ) on Tuesday September 29, 2015 @07:43AM (#50619049)

          Aaah excellent more maker hate from randos on the internet. I don't get the sheer level of vitriol aimed at people who instead of sitting on their arses watching TV or whining on the internet actually get up and do something with their time. Jealousy, perhaps?

          GP does come across as unnecessarily insulting. That's not a justification for ad hominem in return, though.

          A few things:

          (1) There *IS* a significant difference between the modern "maker" and the traditional "craftsman." In general, the sense I get of the maker movement is that it does not focus on specialization -- rather on general familiarity with a wide variety of tools, equipment, and approaches. This is quite different from a traditional craftsman, who might spend years apprenticing to learn a specific subset of skills, then decades perfecting those skills. One cannot compare a "maker" who learned how to use a power saw last week to help with his random electronics project that has a wood frame with a carpenter who has been doing complex woodworking for 25 years. I think that's kinda the point GP was making, even if it was expressed poorly. And it's a legitimate point.

          (2) Of the few self-identified "makers" I've conversed with for any period of time, most of them have in fact come across as pretentious dilettantes who don't really know much of anything about traditional crafts. Yet they act like all of their knowledge is so powerful and deep. I'm not claiming my sample is representative, but it is what I've observed.

          (3) I have absolutely nothing against most of the "maker" goals. Being familiar with "how stuff works" and "how to do things" used to be, well, common knowledge. Reviving these skills and encouraging inventiveness and creativity with physical objects is in general a very good thing.

          (4) That said, because of my experiences with the pretentious idiots above, I would never want anyone to refer to me as a "maker," despite the fact that I value many of the same skills and have for decades. I also don't consider that most of my skills qualify me for any special title -- they're just general purpose things that any person should be familiar with, like basic woodworking, mechanical know-how, electronics, etc. Just because I've built some of my own things out of wood and tend to take apart an electric device to try to fix it (rather than throwing it out right away and buying a new one) doesn't grant me any special status -- it's just living life and being a well-rounded person with some practical skills.

          What I find particularly unattractive about the "maker" designation is how they've tried to co-opt every person who does just about anything and try to act like they are part of this "movement." Recently, when I told someone that I bake bread rather than buy it from the store, ferment stuff, experiment with making soft cheeses, occasionally can things, and do a few other things in the kitchen, they asked whether I was a "maker."

          What the heck? No -- I'm doing exactly what my grandmother did. It's practical, useful skills in my kitchen that save me money and frankly produce food that tastes better than anything I can buy in grocery store.

          Have you ever sewn something? Have you ever made your own soap? Do you compost in your backyard? Apparently, you too can be a maker [wikipedia.org].

          For some people, it's gotten to the point that having any basic practical skill which most people send out to a 3rd party turns you into a "maker."

          And most of the time, the emphasis that I've heard from the self-identified "makers" I know is on simplicity and deliberate avoidance of advanced skills. The typical "maker" isn't striving to create a beautiful ornate cabinet with inlaid wood of four different colors -- no... the "maker" wants to be able have a "recipe" that chops up a pre-fabricated door into seven parts and reassembles it as an ugly, but functional cabinet in an afterno

          • So yes, "This guy wasn't a Maker" -- he was something else. And that's okay. You don't have to force him to posthumously join your movement.

            What makes you assume I'm a maker and that it's my movement? I don't identify particularly strongly with the maker movement. I prefer to think of myself as an engineer.

          • Re: (Score:2)

            by TWX ( 665546 )

            (2) Of the few self-identified "makers" I've conversed with for any period of time, most of them have in fact come across as pretentious dilettantes who don't really know much of anything about traditional crafts. Yet they act like all of their knowledge is so powerful and deep. I'm not claiming my sample is representative, but it is what I've observed.

            ...

            I also don't consider that most of my skills qualify me for any special title -- they're just general purpose things that any person should be familiar with, like basic woodworking, mechanical know-how, electronics, etc. Just because I've built some of my own things out of wood and tend to take apart an electric device to try to fix it (rather than throwing it out right away and buying a new one) doesn't grant me any special status -- it's just living life and being a well-rounded person with some practical skills.

            That's the bulk of what bothers me. I've built projects in wood, in metal, and in plastic for myself and helping others. That makes me a hobbyist in these fields, not an expert or anyone deserving of a title. I spend a lot of time researching what I'm going to do because I don't have the training to know how to do it right. Without that training I don't deserve any special title.

            As far as actual learned trades are concerned, I professionally service computers and electronic devices down to some compo

        • Re: (Score:3)

          by LWATCDR ( 28044 )

          Because maker is frankly an annoying marketing term. Look at old Popular Science, Popular Mechanics,and or Radio/Electronics magazines from the 40 to the 70s and you will see all sorts of projects. Look at the computer magazines like Byte, Computer, and Creative Computing from the 70s and 80s and you will see lots of hardware projects and lots of code.
          Ham radio and the EAA are two examples of communities that were making things far before anyone used the term Maker.
          Harrison is not a maker because he was a p

          • Re: (Score:2)

            by TWX ( 665546 )

            The marketing hype that goes with it is what gets to me. The idea that this is somehow a new thing is a really annoying thing.

            EXACTLY!

            Go learn how to do all of the cool things that you want! Build all kinds of nifty things! Just don't assume that you're somehow better or more capable when most of the rest of us have just been relatively silently doing these things for years or decades, or pretend that what you're doing is somehow new or novel or unique.

        • This guy wasn't a Maker, he actually knew how to do things and how to use hand tools to achieve his goals.

          Aaah excellent more maker hate from randos on the internet. I don't get the sheer level of vitriol aimed at people who instead of sitting on their arses watching TV or whining on the internet actually get up and do something with their time. Jealousy, perhaps?

          You don't get it either because you don't want to get it, or you're terminally clueless. The hate isn't against people who "get up and do someth

      • This guy wasn't a Maker, he actually knew how to do things and how to use hand tools to achieve his goals.

        So what you're saying is that he made things? My dictionary says that makes him a maker. Maybe you should get one. I hear they've been around for a while.

      • the first device to be unaffected by the motions of the vessel in the water, which were what caused all previous models to fail when they otherwise worked on land.

        Actually, I think his first model - the H1 did handle the (pseudo-)random motion at sea well enough to have won the prize on those terms. That was the (approx) 1m cube of machinery, with 2 long spring-loaded motion-detecting gymballed rods sticking out of the top, and is the device in the RGO (Royal Greenwich Observatory). UNFORTUNATELY, while th

    • Re: (Score:1)

      by Anonymous Coward

      This is a guy who was a Maker -- self taught and more.

      No, he was a craftsman, a word that actually means something.

    • I read that years ago, and it fascinated me even as a teenager. It combined elements of engineering and navigation in ways that I hadn't ever considered, and this makes me want to seek out that book again.

    • It really is very good, if memory serves. It was about ten years ago that I read it ...

  • GPS (Score:2, Funny)

    by Anonymous Coward

    Here's an interesting fact: when at sea you can't establish your longitude without a reliable clock.

    Not true. You can use GPS.

    • Re: GPS (Score:5, Informative)

      by johnwallace123 ( 1173071 ) on Monday September 28, 2015 @07:42PM (#50616971)

      And of course GPS is nothing more than very accurate clocks in orbit. So you're still using a clock to get your longitude (4 of them, in fact!).

      • Re: (Score:2)

        by Sangui5 ( 12317 )
        Five... you need one locally too, even though you get to calibrate it from the other four.
    • Which uses very accurate clocks...

    • Re: (Score:3, Interesting)

      by sexconker ( 1179573 )

      GPS relies on clocks, but it's still not true.
      You can use any fixed point of reference and triangulation to determine longitude.

      You just can't use the stars or the sun because the Earth rotates and you'd need to now what time it was in order to know what their position would be.

      You can use just about any continent or any large island if you have accurate maps.
      You can also use the moon if you carefully watch it change to its fullest or wait for the tiniest sliver to vanish, for example. The phases of the mo

      • Re:GPS (Score:5, Informative)

        by ceoyoyo ( 59147 ) on Monday September 28, 2015 @09:11PM (#50617343)

        An easier way to use the moon is by measuring it's position relative to the stars. Then you don't have to wait for a particular phase. In fact, that's the method that was in competition with Harrison.

        • Re: GPS (Score:1)

          by Anonymous Coward

          Here, here! Mod parent up. Relative lunar position is much easier than these so-called chronographic contraptions. Excuse me whilst I shoot a celestial bearing to Polaris - the clouds have briely cleared, and I may now navigate my motor-coach to the seven elevens trading post.

        • Re: (Score:2)

          by T.E.D. ( 34228 )

          An easier way to use the moon is by measuring it's position relative to the stars. Then you don't have to wait for a particular phase. In fact, that's the method that was in competition with Harrison

          Not just competition. The people in charge of the prize always intended to give it out to someone using some variation of this method. That's why they had so much trouble wrapping their minds around the concept that the problem had been "solved" with clocks. To them, that was at best cheating, and more accurately not solving the exact problem they were thinking of.

        • and knew his longitude, but it is apparently hard to do and few people were good at it.

      • You can use just about any continent or any large island if you have accurate maps.

        While your solution of finding your position on the open sea by not being on the open sea shows a degree of lateral thinking, it does rather skip the difficult bit about finding land in the first place without running into it and, like, totally sinking and dying and stuff. [wikipedia.org]

  • You do not need a clock to determine longitude. In fact, a sextant can be used, as long as you have the appropriate tables that map various celestial angles to the correct date and time. These tables were originally overseen by Nevil Maskelyne, one of Harrison's rivals to the longitude prize. The two methods are an early instance of the closed-tech vs open-tech argument we're so used to now. Maskelyne argued that mariners should not depend on Harrison's (closed) bespoke clocks. Instead, he said that open i

    • Re:this write-up is wrong (Score:4, Informative)

      by Sangui5 ( 12317 ) on Monday September 28, 2015 @08:48PM (#50617263)

      You do not need a clock to determine longitude. In fact, a sextant can be used, as long as you have the appropriate tables that map various celestial angles to the correct date and time. These tables were originally overseen by Nevil Maskelyne, one of Harrison's rivals to the longitude prize.

      I was going to bring up myself that technically, you don't need a clock, because of the lunar distance method. However, that's only a "technically"; the lunar distance method was never really practical for use at sea.

      The two methods are an early instance of the closed-tech vs open-tech argument we're so used to now.

      To call it open vs closed is a little bit of an overstatement. Harrison disclosed how his clocks worked and their method of manufacture. He did have patents on some of the techniques, but for the speed technology moved at the time, the length of the patents were quite reasonable. (Also, IIRC the admiralty was allowed to licence it out to others for a fixed rate).

      The big thing is that longitude is hard. To this day a mechanical clock which can keep time well enough for accurate navigation is an expensive and specialized thing. Irrespective of patents, such clocks were simply expensive to build. However, once you bought one, they were easy to use. The lunar distance method required little in the way of equipment (that is, it had low capital outlay). However, it required highly accurate relative measures of many astrological features in a short time. From the deck of a rolling ship. With finicky table lookups. At night. With a bunch of finicky calculations afterwards. And of course, if it was partly cloudy and you couldn't make all of your measurements, well, you'd better hope your sand watch (that is, hourglass) had good holdover. That is, even with the lunar distance method, you still had to have good timekeeping to figure out your in between positions.

      The insurance companies (that is, Lloyd's and their subgroups) eventually forced mercantile adoption of Harrison's clocks. And of course, today we just use clocks. Atomic clocks moving in relativistic conditions, but still easier than the lunar distance method.

      • Re:this write-up is wrong (Score:4, Informative)

        by ceoyoyo ( 59147 ) on Monday September 28, 2015 @09:18PM (#50617371)

        Lunars aren't that hard. I've done them from a sailboat. They're a bit more finicky than straight elevation observations, but not that much. Determining latitude with a sextant ALSO requires finicky observations, error prone table lookups and/or a bunch of calculations. And you can only do it at dawn, dusk or noon (NOT at night), unless you have one of those newfangled lighted bubble levels (good luck using one of those at sea) and not in bad weather.

        The big reason clocks won out over lunars is that Harrison's clocks were more accurate.

        • Re: (Score:1)

          by Sangui5 ( 12317 )
          Perhaps I should be more specific in my criticism of lunars.

          At the time, you could get good accuracy out of either clocks or lunar distances. However, it required either really really highly trained trained and disciplined crew (for lunars), or very very expensive clocks. If you're just using lunars, you have to be quick about it to get a good fix, and then you have to do a good job of your dead reckoning to track your position until you get another absolute fix. In any sort of poor conditions, your de

      • Maskelyne's method was useful and used for exploration. If you find new land, put your telescope on land and find its position. There are other methods of longitude calculation using other astronomical observations.

        • Re: (Score:1)

          by Sangui5 ( 12317 )
          Um... Maskelyne's method is the lunar distance method. Although he also used observations of the moons of Jupiter for measuring fixed locations on earth. Maskelyne was in charge of running the tests for several longitude methods, but the only two that were taken seriously for use at sea after the first trials (indeed, even during the first trials) were the lunar distance method and good clocks (specifically that made by Harrison).

    • You do not need a clock to determine longitude.

      Yes you do. Maskelyne's method just uses the moon as a clock and required being able to accurately measure the angular separation between the moon and a bright star near its path to determine the time. Since the moon moves ~0.5 degrees every hour you need to measure the angle to at least this accuracy to get a time. While it worked it required great care measuring the angles, complex tables to convert the angle to a time and a clear view of the night sky. Even with all this extra effort on the one voyage w

  • "when at sea you can't establish your longitude without a reliable clock"

    But you could on land?

    Imagine if you were in the middle of the prairie in the early 1800's - is it any easier to find your location than at sea.

    • Yes, you can on land find your position with a telescope and some reference tables.

    • Re: (Score:2)

      by gl4ss ( 559668 )

      yes, quite a lot easier.

      first off, if you go to sleep and you wake up you're most likely to be still in the same place.

      second, you're more than likely to see some kind of landmarks.

      maybe being in the middle of sahara is somewhat comparable.. but even then your likely to know your longitude by 50 km accuracy at least anyways, enabling you to navigate to some landmark or another.

    • Lunar method requires highly accurate measurement of celestial objects with a telescope. It is easier to do that on non moving land then it is to do it on a rolling ship.

    • Re: (Score:2)

      by Ozoner ( 1406169 )

      There is a routine way to measure Longitude on land which uses some external method the establish the exact time of local noon (eg a lunar eclipse, the transit of Venus, the position of Jupiter's moons), then this information is conveyed (by mail) to the nearest observatory, who can then calculate your position for you.

      I recall that this was one of the reasons that astronomers made long voyages to carefully measure the Transit of Venus or Mercury.

      https://en.wikipedia.org/wiki/... [wikipedia.org]

    • Re: (Score:2)

      by LWATCDR ( 28044 )

      Actually yes.
      1. You probably had roads.
      2. With a compass you can tell direction.
      3. You have a good idea how far you go each day
      4 You go in the direction you are pointed. You do not have a drift like you do on water.

      Dead reckoning or simple IFR works well.

      IFR in this case means "I follow roads" or maybe back then I follow trails. or even I follow rivers. Back then navigating on water was much harder than on land.

    • The problem with using a clock at sea, as opposed to on land, was that the constant and highly varied movement of the ship disrupted the clockwork mechanisms of the day. So yes, you still needed an accurate clock to use this same method on land, but engineering a clock for such use on land was already accomplished.

  • Why is this a Slashdot article, today? Yes, it was interesting when the book was released, and when the documentaries aired, but if Slashdot ran an article each time a reader rediscovered history....

  • A few years ago I measured my longitude myself, just for fun. I measured the time of local noon, using a portable shortwave radio tuned to WWV. Correct local solar time to mean time with the equation of time, read off my longitude. I would have won the prize. Shows what an accurate clock can do.

    I've read Captain Cook's logs and in his time they observed things like the moons of Jupiter to get a time reference. Reasonably accurate, but time-consuming.

    ...laura

  • It was far too expensive to practically manufacture in the day. The prize authors should have included a clause to limit the manufacturing expense, but they didn't think of it at the time, and were surprised. But, it was not an open society, and monarchies can change the rules on a whim.

    • A committee of bureaucrats decides to enforce a rule that doesn't exist. The King tells them to sod off, and he's in the wrong?

    • Re:No Cost Clause (Score:4, Interesting)

      by serviscope_minor ( 664417 ) on Tuesday September 29, 2015 @03:48AM (#50618397) Journal

      It was far too expensive to practically manufacture in the day.

      It was expensive, but not too expensive. Ships were also expensive. Entire fleets of warships and the upkeep of the sailors and marines even more so.

      But, it was not an open society, and monarchies can change the rules on a whim.

      You know you're exactly back to front? The government through the longitude commission kept on changing the rules. The king weighed in and convinced them to stick to the rules. So it was actually the monarchy keeping the government honest.

      • It was expensive, but not too expensive. Ships were also expensive. Entire fleets of warships and the upkeep of the sailors and marines even more so.

        Yes, but when a quarter of the price of the ship is the clock, I'd say there's an argument that costs need to be reduced before it's really "practical".

  • Several of Harrison's clocks are on display at Greenwich Observatory in London. The more interesting ones to see are the larger ones because the mechanism can be determined. Amazingly the larger clocks are accurate despite being made largely out of WOOD. As well as the rolling of the ship not affecting the mechanism, temperature and humidity are compensated for. Often friction and wear and the need for lubrication are avoided by axles rolling back and forth rather then revolving in a bearing. Dana Sobel's b

Slashdot Top Deals

I THINK THEY SHOULD CONTINUE the policy of not giving a Nobel Prize for paneling. -- Jack Handley, The New Mexican, 1988.

Close