Water level markings and payment card: what they have in common

1. Step 1. Water level markings — is part of — Water clock (clepsydra). Hour marks on the wall.
2. Step 2. Water clock (clepsydra) — evolved into — Mechanical clock. Mechanical clocks replaced water clocks, swapping the flow of water for an escapement.
3. Step 3. Mechanical clock — is part of — Parking meter. A clock mechanism.
4. Step 4. Parking meter — evolved from — Vending machine. A payment machine.
5. Step 5. Vending machine — includes — ATM. A dispensing machine.
6. Step 6. ATM — uses — Payment card. It dispenses money for a card.

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