Lighthouse
device · 280 BC · Ancient world
A tower with a fire for navigation; the Lighthouse of Alexandria.
What it is made of
- Lighthouse tower — has part. A tall base for the light source.
- Fresnel lens — has part. A stepped lens gathers the light into a beam.
- Lighthouse lamp — has part. The lamp: oil, kerosene, then electricity.
- Rotation mechanism — has part. It rotates the optics, setting the flash pattern.
Principles and materials it uses
- Combustion — uses. Ancient lighthouses shone with fire.
- Stone — is made of. The Lighthouse of Alexandria was a stone tower.
Where it is used
- Seaport — is part of. A lighthouse.