Autogyro and conveyor belt: what they have in common

1. Step 1. Autogyro — has part — Propeller. A tractor propeller.
2. Step 2. Propeller — is part of — Submarine. A propeller.
3. Step 3. Submarine — is made of — Leather. It was covered with leather.
4. Step 4. Leather — is material for — Conveyor belt. The first belts were leather.

Open Evothings