With the use of the cards, Hollerith made a number of modifications to the system. He replaced the drum design with a press. Under this new design, the data card would be sandwiched between the two halves of the press. The ambulatory top half, which contained the pins, was pulled down on top of the stationary bottom half.
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The pins that were positioned over holes would be able to pass through the cards. Upon passing through the cards, the pins became submerged in mercury, thus completing the circuit. As in the old design completion of the circuit registered a hit on the counter. |
Hollerith's tabulating machine |
Introduction | Hollerith finds employment with the Census Bureau | The Influence of Dr. Billings | The Jacquard Loom | Hollerith's First Design | Advantages of Hollerith's Device | Hollerith Cards | Modifactions to Hollerith's Device | Field Testing | The Problem of the Census | The Evolution of Hollerith's System | The TwelfthCensus | Hollerith's Success | Resources
