Smithsonian
  • Navigating
    at Sea
    • Challenges of Sea Navigation
    • Navigating Without a Clock
    • The Longitude Problem
    • The U.S. Goes to Sea
    • Navigate at Sea! Activity
  • Navigating
    in the Air
    • Challenges of Air Navigation
    • Early Air Navigators
    • Navigation at War
    • Navigate the Skies! Activity
  • Navigating
    in Space
    • Challenges of Space Navigation
    • Reaching for the Moon
    • Navigating in Deep Space
    • Navigate in Space! Activity
  • Satellite Navigation
    • Challenges of Satellite Navigation
    • Reliable Global Navigation
    • Global Positioning System (GPS)
    • Who Uses Satellite Navigation
  • Navigation
    for Everyone
    • Meet a Professional Navigator
    • Personal Navigation Stories
  • Timeline of Innovation
  • Artifacts
  • Learning Resources
  • Multimedia Gallery
  • Research
  • Visit the Exhibition

Search form

Time and Navigation Home
Facebook Twitter YouTube Pinterest
Time and Navigation
The untold story of getting from here to there.
Home

Search form

  • Navigating at Sea
  • Navigating in the Air
  • Navigating in Space
  • Satellite Navigation
  • Navigation for Everyone
  • Timeline of Innovation
  • Artifacts
  • Learning Resources
  • Multimedia Gallery
  • Research Journal
  • Visit the Exhibition
  • Challenges of Sea Navigation
    • Navigation Gone Wrong: A British Fleet is Lost at Sea
    • Navigate at Sea! Activity
  • Navigating Without a Clock
    • Early Voyages
    • Dead Reckoning
    • Celestial Navigation
  • The Longitude Problem
    • Cash for Creativity
    • Early Sea Clock Experiments
    • Innovations in England
    • Innovations in France
    • The Chronometer
    • Observing the Skies
    • Navigation Gone Wrong: Wreck of the Arniston
  • The U.S. Goes to Sea
    • Early Contributions
      • Meet the Clockmaker: William Cranch Bond
      • Meet the Navigator: Eleanor Creesy
    • Wilkes Expedition
      • Meet the Mapmaker: Charles Wilkes
      • Maps and Charts
      • The "Scientifics"
  • Navigate at Sea! Activity

Explore More

Galileo’s Giovilabio Replica »
Mice »
William Dunlop Brackenridge »
"Ships in Distress off a Rocky Coast," 1667 »
Wolves »

Innovations in France

Finding longitude at sea was a major preoccupation in France.

Thanks to a bequest from Rouillé de Meslay, the French Academy of Sciences offered prizes for improving navigation and scientific voyaging beginning in 1714, just before the English Parliament’s prize was authorized. By the 1760s, two competing clockmakers—Pierre LeRoy and Ferdinand Berthoud—devised marine timekeepers that underwent test voyages in 1769 and 1771.

Pierre LeRoy

After building three earlier marine timekeepers, Pierre LeRoy completed a sea clock in 1766 that contained the elements of the modern chronometer—a specialized escapement, a specialized balance spring, and a balance that compensated for temperature changes. In 1769, the academy rewarded him with a Meslay prize for his work. Like Harrison’s timepieces, LeRoy’s were complex, and his work was not copied directly by others.

Ferdinand Berthoud

A Swiss expatriate working in Paris, Ferdinand Berthoud, saw John Harrison’s earliest marine clocks in England and went on to produce his own. His timekeepers never bested Pierre LeRoy’s in sea trials, but Berthoud made many more than his rival. He claimed that over 50 of his timepieces went on 80 voyages. One of Berthoud‘s sea clocks, an uncommon weight-driven design, inspired Boston clockmaker William Bond to make a chronometer in the same style.

232-sil33-224_001.jpg

Escapement for Pierre LeRoy's marine clock, 1766
This illustration from 1766 depicts the improved escapement in Le Roy’s marine clock.
Credit: Smithsonian Institution Libraries

232-dsc00754-ash.jpg

Ferdinand Berthoud's marine clock, No. 24, 1782
Ferdinand Berthoud, a Swiss clockmaker serving the king of France, produced many marine clocks.
Credit: National Air and Space Museum, Smithsonian Institution
previous pauseresume next
  • Navigating at Sea
    • Challenges of Sea Navigation
    • Navigating Without a Clock
    • The Longitude Problem
      • Cash for Creativity
      • Early Sea Clock Experiments
      • Innovations in England
      • Innovations in France
      • The Chronometer
      • Observing the Skies
      • Navigation Gone Wrong: Wreck of the Arniston
    • The U.S. Goes to Sea
    • Navigate at Sea! Activity
  • Navigating in the Air
    • Challenges of Air Navigation
    • Early Air Navigators
    • Navigation at War
    • Navigate the Skies! Activity
  • Navigating in Space
    • Challenges of Space Navigation
    • Reaching for the Moon
    • Navigating in Deep Space
    • Navigate in Space! Activity
  • Satellite Navigation
    • Challenges of Satellite Navigation
    • Reliable Global Navigation
    • Global Positioning System (GPS)
    • Who Uses Satellite Navigation
  • Navigation for Everyone
    • Meet a Professional Navigator
    • Personal Navigation Stories
  • Timeline of Innovation
  • Artifacts
  • Learning Resources
  • Multimedia Gallery
  • Research
  • Visit the Exhibition
  • Terms of Use
  • Privacy
  • Contact
  • Sponsors
  • Press
  • Donate
Smithsonian Logo National Air and Space Museum Home National Air and Space Museum Home National Museum of American History Home
Smithsonian
Home Facebook Twitter Google Plus Pinterest YouTube

This exhibition is a collaboration between the National Air and Space Museum and the National Museum of American History.

Sponsors | Contact | Terms of Use | Privacy