Mercury cistern and windlass: what they have in common

1. Step 1. Mercury cistern — is part of — Barometer. An open reservoir.
2. Step 2. Barometer — is part of — Weather station. A barometer.
3. Step 3. Weather station — has part — Hygrometer. A hygrometer.
4. Step 4. Hygrometer — is made of — Plant fibre. Humidity was shown by a fibre that changed length.
5. Step 5. Plant fibre — is material for — Rope. Rope is twisted from plant fibres.
6. Step 6. Rope — is part of — Windlass. A rope.

Open Evothings