Compass
device · 1100 · Middle Ages
A magnetic needle that points north.
What it is made of
- Permanent magnet — has part. The needle is a magnet.
Principles and materials it uses
- Magnetism — uses. The needle aligns with the Earth’s magnetic field.
- Iron — is made of. The needle is a magnetized iron needle.
Where it is used
- Sailing ship — is part of. A magnetic compass.
- Caravel — is part of. A magnetic compass.
History: what it evolved from and what it influenced
- South-pointing spoon (Chinese compass) — evolved from. A magnetic pointer.
- Gyrocompass — evolved into. A compass without a magnet.
Things built in a similar way
- Hall sensor — works like. Both sense the Earth’s magnetic field.