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Marine Chronometer

Marine Engineering

A marine chronometer is a precision timepiece carried aboard ships to determine a vessel's longitude through celestial navigation, by comparing the time at a fixed reference meridian with local time observed at sea. The English carpenter and clockmaker John Harrison developed the first true marine chronometer after thirty-one years of experimentation, completing his fourth design, the H4, in 1761. Accurate knowledge of time over a long sea voyage was vital to safe navigation in an age with no electronic or communication aids, and the marine chronometer, among the most exact portable mechanical timepieces ever built, is credited with helping secure British naval and commercial dominance at sea.

Facts
Year
1761 1
Significance
The marine chronometer was the culmination of John Harrison's 31 years of experimentation and testing, and its accurate timekeeping at sea revolutionized naval and later aerial navigation. 1
FAQs

How accurate did a marine chronometer need to be?

Harrison aimed for a portable clock accurate to within three seconds a day.

John Harrison set out to devise a portable clock that kept time to within three seconds a day. That would make it far more accurate than even the best watches of the time.

Why does the Harrison H4 tick so fast?

H4 ticks five times a second because its large balance beats faster than a typical watch.

H4 ticks five times a second, because its large balance beats more quickly and with larger oscillations than a typical watch. Although it initially looked like a large pocket watch, the instrument was quite different, and its rapid ticking is the secret of its design.
Connections

Associated With

Marine Engineering, Fields

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In Field

Source Marine chronometer (Wikipedia)Wikipedia contributors
Sources
1. Marine chronometer (Wikipedia)
Wikipedia contributors, Wikimedia Foundation
  • Harrison paragraph
    Harrison solved the precision problems with his much smaller H4 chronometer design in 1761.
  • Lead section
    The first true chronometer was the life work of one man, John Harrison, spanning 31 years of persistent experimentation and testing that revolutionized naval (and later aerial) navigation.
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