Baseball bat barrel and boiler: what they have in common

1. Step 1. Baseball bat barrel — is part of — Baseball bat. A thick striking part.
2. Step 2. Baseball bat — has part — Handle. A thin handle.
3. Step 3. Handle — is part of — Hammer. A handle.
4. Step 4. Hammer — evolved into — Steam hammer. A steam hammer is a hammer lifted by steam, used to forge huge parts.
5. Step 5. Steam hammer — has part — Boiler. A boiler supplies the steam.

Open Evothings