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This equipment is representative of the tabulating system invented and built for the U.S. Census Bureau by Herman Hollerith (1860-1929). After observing a train conductor punching railroad tickets to identify passengers, Hollerith conceived and developed the idea of using punched holes to record facts about people. These machines were first used in compiling the 1890 Census. Hollerith's patents were later acquired by the Computing-Tabulating-Recording Co. (which was renamed IBM in 1924) and this work became the basis of the IBM Punched Card System. Hollerith's tabulator used simple clock-like counting devices. When an electrical circuit was closed (through a punched hole in a predetermined position on the card), each counter was actuated by an electromagnet. The unit's pointer (clock hand) moved one step each time the magnet was energized. The circuits to the electromagnets were closed by means of a hand-operated press type card reader. The operator placed each card in the reader, pulled down the lever and removed the card after each punched hole was counted. (VV2139)
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