Sled runners and steam turbine: what they have in common

1. Step 1. Sled runners — is part of — Sledge. They glide over the snow.
2. Step 2. Sledge — evolved into — Cart. The wheeled cart replaced drag sledges and sleds.
3. Step 3. Cart — has part — Wheel. A cart rolls on wheels.
4. Step 4. Wheel — includes — Water wheel. A water wheel is a wheel with paddles turned by flowing water.
5. Step 5. Water wheel — evolved into — Turbine. The water turbine evolved from the water wheel.
6. Step 6. Turbine — includes — Steam turbine. A kind of turbine.

Open Evothings