What hollerith tabulator is made of
An electromechanical machine for processing census data from punched cards.
- Punched card reading press — has part. Needles pass through the holes and close the circuit in mercury.
- Electromechanical dial counters — has part. Dials that count the pulses.
- Relay — has part. Relays controlled the sorting box.
- Punched card — uses. The 1890 census data was encoded on punched cards.
- Electromagnetism — uses. The counters click with electromagnets.
- Cast iron — is made of. The casing is cast iron.
- Copper — is made of. The contacts are copper pins dipping into mercury.