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Longitude, Sailing pre 18th Century, and under-rated carpenters/Inventors


beecee

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Pre 18th Century, Sailing was a risky business, with only being able to determine one's position by Dead Reckoning and Latitude. While Latitude could be readily calculated, longitude was unknown with no means to determine, once out of Land sight. Sailors pre 18th century would follow known Latitudes until reaching a familiar land form. This was called "westing" or "easting" depending on the direction sailing, and would have been the method I presume that Columbus made, when  reaching the Americas.

The latest time machines of the day, pendulum clocks, were obviously useless at sea, due to the instability.

This problem was seen so urgent to overcome that in the early 1700's, Britain established "The board of  Longitude" and offered a grand prize to anyone that could solve this vexing problem.

Then along came a self taught Carpenter, named John Harrison, with an Interest in time and time keeping devices. His story and perseverence in finally creating a marine chronometer over 40 years of efforts, is told here.....https://en.wikipedia.org/wiki/John_Harrison

I have raised this because he is mostly unknown, and while marine chronometers are now outdated with radio and GPS, the importance of his invention for that time period cannot be underestimated. Captain James Cook used his final chronometer on his Pacific expedition in 1770 to study a solar eclipse in Tahiti, later of course sailing on to map and record the Islands of New Zealand and Australia's east coast. 

I also personally used a ship's chronometer on a barquentine sailing from Panama to Sydney in 1974 and learning navigation via a sextant, by the Sun, Moon, and prominent planets and stars.

Later I also read a great little book, entitled "Longitude" The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time. By an American woman named Dava Sobel.

https://en.wikipedia.org/wiki/Longitude_(book)

 

A truly great notable human being, generally not given the praize he deserves.

Hope others find his story interesting.

 

Edited by beecee
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I read that book a couple of months ago and thoroughly enjoyed it. One solution to longitude I found interesting was I believe proposed by Newton, and involved accurately mapping the Moon's distance from Earth and its irregular motions to allow measurement of background stars relative to the moon to be used for determining longitude.

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32 minutes ago, iNow said:

Absolutely. In hopes of reciprocating a bit, you might enjoy this brief video overview of the history and topic you brought forth here:

 

Yes, thanks for that, some extra knowledge as well as being interestingly enjoyable.

Reading and using a sextant today is probably a lost art, although I think the RAN [ Royal Australian Navy] gives lessons to new recruits...Nautical Solid Brass Sextant, Packaging Type: Corrugated Box, Rs 800 /piece  | ID: 4098145397

The Barquentine I had the pleasure of sailing on and where I learnt how to read and operate a sextant  was called Eolus, a photo of here here........

 

http://c8.alamy.com/comp/B4FWR5/the-sailing-ship-eolus-seen-here-arriving-at-portsmouth-at-the-beginning-B4FWR5.jpg

the-sailing-ship-eolus-seen-here-arriving-at-portsmouth-at-the-beginning-b4fwr5.jpg

Edited by beecee
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