Wagonway and bellows: what they have in common
- Step 1. Wagonway — evolved into — Railway track. Cast-iron and steel rails replaced wooden ones.
- Step 2. Railway track — uses — Rolling mill. Rails are rolled.
- Step 3. Rolling mill — is part of — Steel works. Rolling mills.
- Step 4. Steel works — has part — Blast furnace. Blast furnaces.
- Step 5. Blast furnace — has part — Bellows. Air was blown in by bellows, later by blowers.