Diamond and hollerith tabulator: what they have in common

1. Step 1. Diamond — is a kind of — Carbon. A form of carbon.
2. Step 2. Carbon — is material for — Carbon microphone. Carbon granules.
3. Step 3. Carbon microphone — is part of — Telephone. For a century, telephone microphones were carbon microphones.
4. Step 4. Telephone — uses — Telephone exchange. Connecting subscribers.
5. Step 5. Telephone exchange — has part — Relay. Relay switching.
6. Step 6. Relay — is part of — Hollerith tabulator. Relays controlled the sorting box.

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