Gyroscope and shaduf: what they have in common
- Step 1. Gyroscope — is part of — Torpedo. Obry’s gyroscope keeps the course.
- Step 2. Torpedo — has part — Propeller. Propellers.
- Step 3. Propeller — evolved from — Archimedes’ screw. The first propellers by Smith and Ericsson were a variation on the Archimedes’ screw.
- Step 4. Archimedes’ screw — is used in — Irrigation. The Archimedes’ screw lifted water for irrigation.
- Step 5. Irrigation — uses — Shaduf. The shaduf fed water into the canals.