Exhibits At the Museum

This Day in History

      January 2014
Today: July 28, 2014
Hollerith Electrical Printing and Tabulating Machine.

January 8, 1889

Herman Hollerith Receives a Patent for the Hollerith Tabulating Machine

Herman Hollerith receives a patent for his Hollerith Tabulating Machine, a punch card system that won a contest for a more efficient means of compiling the 1890 US census. To count an item, a small paper card on which a census taker had punched out holes corresponding to a citizen's census information, was fed through a press that sensed holes. A wire passing through the holes into a cup of mercury closed an electrical circuit and registered the item. In 1924, Hollerith's Tabulating Machine Co., and two other firms were consolidated into International Business Machines.

George Stibitz and the K-machine at the dedication of the Dennison display. A replica of the K-machine is now on display at the Smithsonian Institution.

January 8, 1940

Bell Labs' Complex Number Calculator Completed

Bell Labs' Complex Computer, a full-scale relay calculator designed by George Stibitz, was capable of performing complex arithmetic calculations necessary for circuit design. Bell Labs recognized a potential solution to the problem of high-speed complex-number calculation, which was holding back contemporary development of wide-area telephone networks. By late 1938 the laboratory had authorized development of a full-scale relay calculator based on the Stibitz model, and in April 1939 Stibitz and his design team began the construction.