Vannevar Bush Initiates Work in Computation with the Differential Analyzer

American engineer and information visionary Vannevar Bush's work related to the history of information began at MIT in 1930 with the differential analyzer, a large analog computer more accurate than previous devices of this type. Bush's primary paper about this machine was: Bush,V. & Hazen, H., "The Differential Analyzer. A New Machine for Solving Differential Equations," Journal of the Franklin Institute 212 (1931) 447-88. In July 2014 three-dimensional computer graphic images visualizing the Bush differential analyzer were available from the MIT website at this link.

By 1936 Bush was working on the Rapid Arithmetical Machine Project. In a paper called “"Instrumental Analysis" publshed in Bulletin of the American Mathematical Society 42  (1936) pp. 649-69, he suggested how an electromechanical machine might be built to accomplish Charles Babbage’s goals for the Analytical Engine. This was almost exactly one hundred years after Babbage began designing his Analytical Engine. In the same paper Bush wrote that four billion punched cards were being used annually in electric tabulating machines. This amounted to ten thousand tons of punched cards.

On March 7, 1940 Bush wrote a memorandum entitled “Arithmetical Machine.” This memorandum, shows that the Rapid Arithmetical Machine Project begun conceptually in 1936 was already well-advanced. However, Bush continued to focus most of his computational energy on building the Rockefeller Differential Analyzer II, a 50- 100 ton analog machine that included 2000 vacuum tubes and 150 electric motors that was more accurate and faster than the first Differential Analyzer. For security reasons its existence was not publicized until October 1945.