Bronze toads with open mouths and conveyor belt: what they have in common

1. Step 1. Bronze toads with open mouths — is part of — Zhang Heng’s seismoscope. They catch the ball when it drops.
2. Step 2. Zhang Heng’s seismoscope — is made of — Bronze. A bronze vessel.
3. Step 3. Bronze — is material for — Helmet. Ancient helmets were copper and bronze.
4. Step 4. Helmet — is made of — Leather. Helmet liners and simple helmets were made of leather.
5. Step 5. Leather — is material for — Conveyor belt. The first belts were leather.

Open Evothings