Gyrocompass
/ˈdʒaɪroʊˌkʌmpəs/noun
A navigation instrument that finds true north using a spinning gyroscope rather than magnetism.
The Greek roots
Literally: “circle compass”
The story of the word
Foucault spun a rotor in 1852 to make the Earth's rotation visible and called it a gyroscope, the turning-seer. Anschütz-Kaempfe and Elmer Sperry turned that physics into a compass in the decade before 1914: once spinning, the axis holds its direction and settles on true north, ignoring the steel hull that ruins a magnetic needle and caring nothing for magnetic variation. The compass half of the word came from Latin through French, so the term is a hybrid. The same γῦρος gives gyre, and the Greek meat that turns on a vertical spit.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 20th century
Same family
In a sentence
The gyrocompass took forty minutes to settle before they could leave the berth.