Abacus rods and cannon: what they have in common

1. Step 1. Abacus rods — is part of — Abacus. Guides for the beads.
2. Step 2. Abacus — has part — Wooden frame. A frame with rods.
3. Step 3. Wooden frame — is part of — Warp-weighted loom. Two uprights and a beam.
4. Step 4. Warp-weighted loom — uses — Universal gravitation. The warp threads are tensioned by weights.
5. Step 5. Universal gravitation — is used in — Mortar (weapon). The bomb flies on a steep trajectory.
6. Step 6. Mortar (weapon) — is a kind of — Cannon. A gun.

Open Evothings