Multimedia Gallery
- Topic: Timekeeping
Marine chronometers are precise, specialized clocks for finding longitude at sea. They serve as portable time standards.
Chronometers like this one by Arnold & Dent were used on the U.S. Exploring Expedition (1838-1842).
Chronometers like this one by Charles Frodsham were used on the U.S. Exploring Expedition (1838-1842).
Chronometers like this one by Molyneaux & Son were used on the U.S. Exploring Expedition (1838-1842).
Chronometers like this one by Parkinson & Frodsham were used on the U.S. Exploring Expedition (1838-1842).
Tradition says this was the first American-made marine timekeeper taken to sea.
In the 1990s, the NIST-7 was the most accurate clock in the country and helped keep the GPS clocks synchronized.
A rubidium clock like this was tested on the NTS-2 satellite to see if clocks could keep accurate time in space.
The quartz clock keeps better time than the best mechanical clocks.
Beginning in 1961, NASA used this quartz oscillator as the main timing and radio frequency standard at the Goldstone tracking station.
