Determining Longitude with a Clock - Watch and Learn #58
ฝัง
- เผยแพร่เมื่อ 11 พ.ย. 2018
- In today's Watch and Learn, I’ll discuss why the marine chronometer was just an important invention. With it, mariners could determine their longitude, making navigation much more precise.
For more in-depth knowledge of this truly unique topic, check out the literary work of Dava Sobel. I recommend reading the book called Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time and Winner of British Book of The Year.
Download “Longitude” from Google Play Book Store: play.google.com/books/reader?...
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Thank you for watching. - แนวปฏิบัติและการใช้ชีวิต
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I’m always amazed at how ingenious people where without technology. In some ways they possessed superior knowledge because they understood principles rather than relying on modern conveniences. Thanks so much for this video Marc.
Thank you.
i guess it's kinda off topic but do anyone know a good site to watch new movies online ?
Nicely articulated. The people in earlier (past) centuries studied a alot....alot and got into deep thoughts , how to put things in mechanical designs what they studied and understood from books.
@@siddhunkarthik As a modern adult I KNOW the earth orbits the sun and have seen days get longer and shorter over the course of the year my whole life. However, it never really meant anything until I stood at Newgrange in Ireland and again at Copan Ruinas in Honduras and saw how ancient humans built structure that helped them measure that change in the sun’s location. They had to really understand what I take for granted.
Love it! I actually own two old Hamilton marine chronometers from WW2. One of them, Hamilton model 22 with a Swiss lever escapement, keeps +/- 2 seconds a day and it is 75 years old and never been regulated. Although I did have to replace the main spring recently and to my complete surprise, parts are still available for these old instruments. The other one, Hamilton model 21, is a detent escapement with a chain and fusee. It was an observatory instrument but fell into disuse. It still functions well enough but needs to be serviced to bring it back into chronometer spec. The Dava Sobel book is one of my favorites, a great read.
Sounds so cool, thanks for sharing.
That is cool!
*_VERY_* cool! Thanks for sharing; I want to research those now! 👍
Great video. I love the watch and learn spots. Thanks Marc.
Thanks Steve.
Hey Mark, just wanted to thank you again for taking your time to make these educational videos. Looking forward to the next one.
You are welcome, thank you.
Thank you for the watch and learn vids. They are my favorite. I appreciate your passion for horology.
Thank you for taking the mystery out of longitude! Great job presenting a complex subject in understandable terms!
You are welcome!
Nice watch and learn episode!!! Thanks for taking the time to explain this!!!
You're welcome.
I read that book in 1999 and I knew as soon as I saw the title of this video you were going to bring it up. In a nerdy/engineering/navigation/chronometer way its an awesome book.
Thanks for this video! For others here, the clock was made of wood and the natural oils in there lubricated it well enough for it to remain accurate. Plus the wood ( I can't recall which type) resisted expansion and contraction with temp and the oils helped it remain consistent in moisture content.
An excellent watch & learn episode; your content is very to follow and understand!
I can’t even imagine being smart enough to figure out that method with nobody teaching it to me. The person who figured it on his own was beyond brilliant! Thank you Marc. I really look forward to all of your content!
Absolutely stunning geniuses who nailed this down.
Great! Perfect simplified explanation! Thanks Mark!
Love the educational videos from time to time. So to speak. Be well!
Love it, Great simple lesson of a lost art. Kids need to learn the old ways so not to take for granted what we have... YAR!
Absolutely. Back to basics.
A great video for learning, thank you so much for being here sir.
You Tube is a better place with you on it. 👍 👍👍
Fascinating. Loved it.
Thanks.
Thank you for the clear explanation
Great explaination! Congratulations and thank you so much,😊
This finally made it click for me. And it was entertaining. Thank you!
Cool video. I'm not sure how I missed it when it came out. Good thing I scrolled through the watch and learn play list.
Yet again an educational and interesting video! I didnt even know i wanted to know this :D Thanks for making these videos Marc!
LOL, thanks for checking it out.
Thank goodness for the British and their having founded Greenwich Meantime too. The British today still set the international price of gold too; twice every day in London, at 10am and 2pm.
Very interesting. I had often wondered why the chrono was so critical. Thanks Mark.
Very interesting. Thanks for sharing this. 👍
Thank you so much for this explanation, I'm studying watchmaker at university and have to write an essay about this and that just made my life a lot easier :)
I was wandering for years how it work. And now i know! Thanks
Thanks for the informative video
That is actually GENIUS.
I knew it had something to do with clocks but I never sat down to think it through until just now.
Your videos have made my insomnia tolerable. Thanks very much!
Excellent explanation. Excellent.
Thanks!!!!!
Great recommendation Marc. I finished Sobels' Longitude book myself recently. It's a surprisingly easy read and absolutely essential for anyone interested in the history of horology.
Glad you enjoyed it.
Nice and informative video, thanks for sharing Sir 👍
Thanks!
John Harrison’s marine chronometers can be seen at Greenwich observatory, London. Outstanding timepieces. Thank you for the great video.
One day I'll check it out!
Long Island Watch If you come to Greenwich please let me know, I live there! Your video is fab! You explain it so well. I hope you see this message.
Awesome !
Appreciate that.
A pretty workmanlike presentation. The guys on the boat would be impressed.
Very Informative .. Thanks
You are welcome.
thanks man. was just wondering how this works. now I know.
What an excellent summary! I would just add that the accuracy of map making is a consideration in all of this too.
Love this kind of stuff.Cheers,Len
Me too :)
@@islandwatch It's all engineering principles plus a bit of maths and a bit of physics.Put that into the context of the age your discussing and it's superb.In Edingborugh they stood fire a cannon at high noon to set a chronological by.If you new how far away from that point you were when you heard it there was a sound correction for setting the ships clock .On the main port itself there was a ball dropped within a visible tower that denoted noon .Great stuff and thanks for the content.Len.
@@islandwatch Oh it's Edingburgh. And Knew btw!!!! Spellcheck would fail to cross the open seas!!!!!!!! Grrrrrrr.
It’s a good video for Veterans Day
It sure is.
great info video...keep up the great content
Thanks!
Marc I was browsing the site, that Bambino version 4 with the blue fade to black dial is awesome
My fave v4.
Cool demo. I enjoyed it very much.
Glad! Thank you.
Good explanation... they still teach this
Glad to hear that; not sure they still teach drafting in engineering school.
I actually understood that. Usually I try to think of nothin happens.
Great, glad to hear it.
Cool video, Mark. Navigation skills like this are de rigueur for solo atlantic sailors, around the world sailors, etc. I know they practice redundancy with their electronics, but these skills would rescue someone from deep doo-doo in case of electronics failure. 👍⏱
That's exactly why I'm studying this nearly-lost skill.
8:24 Thanks Bob
From one engineer to another (civil here), cool stuff! Thanks!
Welcome!
I once researched how to do this for a couple of hours and all i could find is hours long videos and pages long explanations with bow compasses and complicated trigonometry and you just explained it in 11mins. 6 if you cut out the history lesson. Thank you Sir. Amazing 👍👍👍👍👍👍👍
A great-superb-amazing course in CelNav is available through Starpath School of Navigation in Seattle. They teach online. Rigorous and excellent teaching by super genius David Burch PhD physicist.
very good classes
How you explained it I feel like it's easy to learn more detail navigation too..
Probably not that easy; I'd hate to be the one doing it.
@@islandwatch but you did the longitude part related to watch very well.. Thumbs up
If you’re ever in or around London, go see the marine chronometer H4 on display at Greenwich.
The book "Longitude" is a great read for anyone the least bit interested in horology and the TV movie of the same name also tells the story well. John Harrison spent his entire life fighting for the scientific principle that accurate time keeping is essential to us all knowing exactly where we are on this great planet. My homage to the legacy of his groundwork is to wear a chronometer on my wrist every day.
I haven't seen it yet, but have heard it's a good 'watch'.
Complex but how clever the method is....
Amazing, isn't it?
Dude, now you can start selling sextant's LOL. Seriously tho, think about it, a chronometer, compass and sextant set would be killer. An inexpensive sextant for education purposes are available.
LOL. Beginner's navigation kit.
@@islandwatch It's a niche market LOL.
I have seen a sundial watch some where.
@@seanpatrick78 thanks looks kinda cool
Hello. Gran Seiko have released news (sep 2020) about a 0,5s a day accuracy constant force tourbillon! So now we just need that movement inside a watch.
new sub ,greetings from schenectady ny
I appreciate you still were your gloves for consistency or perhaps for a smudge proof pencil. Enjoyed the video.
My fingers are a mess.
As the great powers wanted to expand their empires and trade routes, they got tired of ships not knowing exactly where they were and slamming and shipwrecking, losing precious cargoes from far away places, into islands, continents, and the like, in the dark hours. Having an idea of where they were enabled them to minimize these navigational risks and helped them expand their empires.
There's a great movie on the Bing website "Twilight for the Gods" (1957) with Rock Hudson. It's about an ill-fated passenger sailing ship traveling from Fiji to Mexico in 1927. The ship starts to leak during the voyage and the crew almost mutinies. Arthur Kennedy sneaks into the Captain's quarters and notices that the chronometer isn't working. Shortly after, Rock Hudson is forced to turn the ship towards Hawaii to save his passengers.
At the risk of sounding like a navigation nerd (years ago I was in the US Coast Guard and served as the Navigator on my Coast Guard cutter - ship), maps show land locations; whereas charts show water locations (often with land along the edges). Water nav: charts. Land nav: maps. Sorry for the nerdiness, but you will sound more authorative using "chart" when speaking water navigation. Otherwise, good explanation! Thanks.
Great video as usual. Dislike'rs must be flat earthers.
LOL. Probably.
Grace O’ Malley
Considered one of the best female sailors of the world, her life presents a tale of heroism, sailing skills and determination. She was born in Ireland and took over sailing after her father’s death. But when she did that, she not only set out to do what she loved but also to prove to the world that she was just as fine as any of her male counterparts when it came to sea life.
Even though history refers her as the greatest female ‘pirate’ of the world, there is no denying the fact that her sailing skills were better than most of the male sailors at the time, hence making her such an efficient pirate. Also it indicates the extent of traditional norms that she broke through her life and earned her current status. Pirate or not, Grace O’ Malley continues to be one of the best female sailors of the world.
Skipper Thuridur
One of the world’s earliest woman sailors, Skipper Thuridur was a celebrated fishing captain in Iceland. Considered to be a pro at sailing and all its aspects especially rowing and steering of heavy wooden open boats, her skills made her one of the most efficient fishing captains in the area.
YOU MONSTER!!
I love these show and tells.
I believe that when Harrison clock returned from the Carribbean it was only out by a short period of time.
I think I may have read it somewhere but I also think TUG may have mentioned something similar.
Amazing stuff!
Long Island Watch Yes, it was his son who did this voyage as by this time Harrison was an old man.
Hi Marc. If youre ever in London. Go check out Harrisons marine chronometers in the Royal observatory in Greenwich. Well worth a visit.
Thank you
Yes Cool..
Indeed.
Thx. Important video. There is a novel by Umberto Eco, L'isola del giorno prima, about exactly this topic. Have fun times.
Thanks; I'll check it out.
Hello sir I am wood worker but I love Omega please tell me what is the different between omega 1012 movement and 565 movement
How did you get the 40 degrees? Out of thin air?
So how many miles were they from home at 30 degrees? Or did miles not matter back then. Very interesting. Thanks
Didn't matter. The # of miles would depend on your latitude, but what's important is that you can get distance in terms of generality. Are you one day from home? Or 10?
Nice video. Thanks! I now have questions though. How did they go about making/ regulating the chronometer in the first place? I'm assuming they didn't have access to a Timegrapher, a stable WiFi connection or a reasonably accurate atomic clock. Edit: Time for google.
Thanks. Accurate clocks did indeed exist; just not chronometers. You cannot use a pendulum, for example, at sea due to the boat pitching.
Love your icon. Commander Keen is my all time favorite game series. The good old MS DOS days.
Hi Mark! I love your videos. However I am an amputee and I don't have
arms. I wish I could have more videos on watches that I could wear,
could you do any watch and learn special for amputees? thanks!
is there an explanation to how they charted the Latitude based on sextant? I assume "reading from a chart" means that people before have already recorded down the angle of the sun relative to Latitude relative to day and month? So all ships just carry this chart?
Yes, but also they know how high the sun gets at different times of the year (charts, again). Because they can do this stuff on land.
I think it was the BBC {please correct me if wrong} on the whole Longitude story and the development of the Harrison clock ie Marine Chronometer. Oh there is or was a replica in the Sydney Maritime Museum.
I wouldn't know, sorry.
To get an idea of why an accurate time piece is needed in order to determine longitude remember that we are attempting to determine our position by calculating our distance from the spot on the Earth's surface where the Sun is directly overhead (called the Sun's geographical position, or GP) which happens to be moving at 900 nautical miles per hour. That's like trying to figure out which off-ramo to take on the highway by measuring how far away you are from a fighter jet flying at Mach 1.5! To get it right you're going to need to know some fancy math and EXACTLY when to take your measurement. In reality, if you can determine your position within a mile or two, that's about as good as you can expect.
How did you deduce from your chronometer that it is A.M or P.M ?
Could be a 24 hour clock.
Nice video.. I feel that writing the 1:30 and 1:45 times confused things a bit. All that matters in calculating longitude is the chronometer time difference between noon at home and noon of the ship. That's 2 hours * 15 deg/hour, equals 30 degrees as you showed. Feel like if you didn't include the 1:30 and 1:45 it would have been perfect.
Have a copy of "Longitude" read it to help relate to Captain Cook when looking at his charts and charts based off his navigation. Cheers for a great watch and learn!
Edit: This is also why almost all charts are in Mercator projection. Much easier to calculate straight vs curved graticule, even if circumstances would be more favorable given distortion.
Thanks for sharing!
I just wanted to make a quick comment on your latest video about your exposure on your other videos where you're holding up the watches with your gloves and everything. You could probably go about half a stop or maybe even a full stop more exposure. Also you should be using a grey card to white balance to when editing your videos sometimes your videos have a bluish tint sometimes they are little warmer you should really be using the same color balance setting on your camera for all of your videos especially if you are able to completely control your lighting. Just a suggestion.
Thanks for that. Let me know how the more recent ones come out.
So two boats going with a speed diference of, let´s for example say, 30 knots going west would be at the same longitude taking in consideration only the time at home, right?
And noon where they were.
where can i purchase this boat that goes over 1500km/h?
jk, good video
I know this is an old video and I love Marc's videos. However, if the angle of the sun is 64 degrees doesn't that mean your latitude is 64 degrees?
Williams Harrison was the first to figure out that small and light was more accurate than big and heavy because less inertia was created by the ship's movement. For roughly the same reason small and light watches make the best beater watches, contrary to what most people think.
Awesome info, thank you.
Yes! But eventually overshadowed by his kid brother Williams Sonoma, purveyor of high end kitchen wares.
doesn't speed of travel matter?, what if the sailor took his sweet time and sailed only a few miles a day, when it is two hours ahead in time, he would be no where near Long 30
Mark, unless I missed something you seemed not to describe the relationship between Sun Angle (Declination of the Sun) and Latitude. You said that the observer would use some on-board charts to derive the latitude from the declination of the Sun.
I realised I did not understand the relationship so, after a brief search, found this:
astronavigationdemystified.com/latitude-from-the-midday-sun/
Thank you for the assistance. No, I did not discuss it.
The navigator on a ship is a Quartermaster.
Thank you.
A quartermaster s the storekeeper as it were , the supply master for goods. The navigator would be the the ships " master" .
nice
Thanks!!!!
i'm here to get explained about how we can find longitude from the clock and i'm still lost x_x
You just have to know the difference in time between Greenwich, England and your noon. Hence the need for an accurate clock.
I get it you are watching the sun climb and you you were using the sexton to find noon when the sexton finally found noon you're speedometer said 2:00 which means that you had moved 30° got you that makes sense.
"We know, that the earth is a circle" - Yes! :D
Now I could be wrong about this, but I thought I read somewhere in Alondra Jr. High that the EARTH is doing all the REVOLVING not the other way around???? Can someone fact check this please and post your own finding? Thanks guys.
Book Longitude was the quest to solve the longitude problem, the marine chronometer won. Book is a great look at how pissed a bunch of scientists were having their a$$Es handed To them by good old country boy with no formal education 😊
Great video but why are you wearing gloves?
Cause my hands are dried and cracked.
Geodetic Engineering 101: Proving Flat Earth is Wrong
Bring one chromometer or three; never bring two.
LOL, tie breaker!
And of course you need a compass so you can determine your longitude
over a longer period of the day, otherwise you'll have to wait for the sun
reaching its highest point at your location and then make your calculations.
Keeping it simple!
Compass does not indicate Longitude. The needle generally points the direction of Magnetic North which varies from True North, a function of Longitude. Depending on the year and location, the Variance, magnetic declination, between magnetic and true north can be as much as 11 or 12 degrees.
@@coolspiritministries a compass in combination with a chronometer of course
got bored