Odometer and needle: what they have in common

1. Step 1. Odometer — has part — Gear. Gear counters.
2. Step 2. Gear — is part of — Lawn mower. The wheels turn the blade cylinder through gears.
3. Step 3. Lawn mower — evolved from — Sickle. Mechanized mowing.
4. Step 4. Sickle — evolved from — Stone tool. The first sickles had flint inserts.
5. Step 5. Stone tool — evolved into — Needle. Bone needles with an eye are part of the Palaeolithic toolkit.

Open Evothings