Draft tube and telephone: what they have in common

1. Step 1. Draft tube — is part of — Water turbine. It carries away water and recovers some of the energy.
2. Step 2. Water turbine — is part of — Hydroelectric power station. Water turbines.
3. Step 3. Hydroelectric power station — has part — Electric generator. Generators.
4. Step 4. Electric generator — has part — Copper wire. Windings.
5. Step 5. Copper wire — is part of — Electrical telegraph. Communication lines.
6. Step 6. Electrical telegraph — evolved into — Telephone. The telephone grew out of attempts to send several signals over telegraph lines (the “harmonic telegraph”).

Open Evothings