Sextant
device · 1731 · Early modern era
An instrument for measuring the altitude of celestial bodies.
Inventors: John Bird, Abu-Mahmud Khujandi.
What it is made of
- Lens — has part. The sextant’s telescope.
- Mirror — has part. Mirrors — the principle of double reflection.
Principles and materials it uses
- Reflection of light — uses. Double reflection brings the celestial body and the horizon together.
- Trigonometry — uses. Navigational calculations.
- Brass — is made of. A sextant is brass.
Where it is used
- Sailing ship — is part of. The sextant and chronometer were a sailing ship’s navigation kit for finding latitude and longitude.
History: what it evolved from and what it influenced
- Octant — evolved from. The sextant is an extended octant.
Things built in a similar way
- Star tracker — works like. Navigating by the stars — as sailors did.