Centuries-Old Longitude Clock Runs Again

douglips writes "BBC News has published a story about John Harrison's H4 chronometer and how it has been wound up for the UK's National Science Week. After 40 years of work [Harrison] proved in 1764 that a clock could be used to locate a ship's position at sea with extraordinary accuracy." Ah, the GPS system of its day. T. adds: This is the timekeeping device which Dava Sobel wrote about in Longitude .

Comments

clock vs watch

[Alien54]

Every one says clock, but what it is really, is a watch.

That is what screwed everyone up at the time, because the majority of folks were into heavy metal and wood and so on. Pendulums are messy on ships.

The spinning mechanisms of mechanical watches are much more stable, and this, with the miniaturization, proved to be the key.

The professionals could not deal with a simple "watch" that was the first chronometer.

Re:A work of genius

[limber]

I definitely agree that the book is an interesting read. Until i came across it, I'd always had the misconception that seafarers could actually determine their relative position to a fixed departure point via the stars. when in fact only the latitude was figurable.

(there is also a description in the book about the rival scheme involving telescopes and star charts fiercely backed by the Royal Astronomer)(can't recall his name -- Maskelyne?)

if you think about it, the pre-Harrison sea captains were a pretty courageous lot -- imagine setting out on a journey and not *really* knowing for sure how far you'd actually travelled! (in terms of degrees of longitude)

The Island of the Day Before

[cindy]

There's a surrealistic novel by Umberto Eco about attempts to solve the longitude problem through alchemy and strange "scientific" experiments 120 years before Harrison. It deals with the blury line between science and supersition at that time (not that it's all that clear now), and with the importance of knowing longitude for military advantage and empire building. A very strange story told through the eyes of a clueless young nobelman trapped into an insane voyage of discovery.

Knowing where you are at

[perdida]

do bot discount the utility of knowing where you are at. the modern stock market came up because bizzes were able to trade and do shit like predict the weather and their upcoming returns.

Investment in the future used to be a non-rational thing. Due to the cultural and religious shit that was impressed upon your kids, you could count on their supporting you in their old age.

When the advanced navigational techniques of the 16th and 17th centuries were developed, people could predict their futures. They would say, :when my ship comes in."

When my ship comes in sounds antique and slow, because a ship could take 2-3 years between leaving, laden with cargo, and returning, bursting with trade.

But, compared to the generation-long gambles on farms and marriages (the prominent speculations of their time), a ship coming in was as rapid a return on investment as a new technology can be today.

It's great to know where we are - exactly where we are, in physical time in space. I am in awe of it, myself. Place yourself in the proper context of history, and you will know the context of your own experience.

Re:good example of a disruptive technology

[CProgrammer98]

Surely solar noon = 12:00 midday so why do you need a second clock? You can get you position fix at midday.

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