This equipment is representative of the tabulating system invented and developed by Herman Hollerith (1860-1929) and built for the U.S. Census Bureau. These machines were first used in compiling the 1890 Census. Hollerith's patents were acquired by the Computing-Tabulating-Recording Co. (which later became IBM), and this work became the basis of the IBM Punched Card System. The first "tabulator" used simple clock-like counting devices. When an electrical circuit is closed (through a punched hole in a predetermined position on the card), each counter is actuated by an electromagnet. The unit's pointer (clock hand) moves one step each time the magnet is energized. The circuits to the electromagnets are closed by means of a hand-operated press type card reader. The operator places each card in the reader, pulls down a lever, and removes the card after each punched hole is counted.