Flour sieve and needle: what they have in common
- Step 1. Flour sieve — is part of — Gristmill. It separates flour from bran.
- Step 2. Gristmill — evolved from — Quern. The mill mechanized hand-turned millstones.
- Step 3. Quern — is a kind of — Stone tool. A quern is two stones: the upper one is turned on the lower to grind grain.
- Step 4. Stone tool — evolved into — Needle. Bone needles with an eye are part of the Palaeolithic toolkit.