Hoe and centrifugal pump: what they have in common

1. Step 1. Hoe — evolved from — Stone tool. Neolithic hoes of stone and antler.
2. Step 2. Stone tool — evolved into — Hammer. The first hammer was a stone in the hand.
3. Step 3. Hammer — evolved into — Steam hammer. A steam hammer is a hammer lifted by steam, used to forge huge parts.
4. Step 4. Steam hammer — has part — Boiler. A boiler supplies the steam.
5. Step 5. Boiler — is part of — Central heating. A boiler.
6. Step 6. Central heating — has part — Centrifugal pump. A circulation pump.

Open Evothings