Hourglass
device · 1300 · Middle Ages
Measuring time with pouring sand.
What it is made of
- Two glass bulbs — has part. Glass vessels.
- Hourglass neck — has part. A narrow neck sets the rate.
- Hourglass wooden frame — has part. A protective frame.
Principles and materials it uses
- Gravity flow — uses. Sand pours through under gravity.
- Glass — is made of. Bulbs.
- Fine sand — is made of. Fine, uniform sand.
Where it is used
- Chip log — is used in. The time of a speed measurement was taken with an hourglass.
Things built in a similar way
- Water clock (clepsydra) — works like. The same principle of timing by outflow, with sand instead of water.