Room-sized differential analyzers were among the largest computing devices built before the advent of mainframe computers. The first was completed in 1930 by Vannevar Bush and his associates at MIT for use in solving a wide range of second-order differential equations of practical importance. Further funding from the Rockefeller Foundation made possible the building of an improved differential analyzer at MIT, with the original going to Wright University in Dayton, Ohio. Differential analyzers also were built for ballistics calculations at Aberdeen Proving Ground, for astrophysical research in Norway, and at Cambridge and at Manchester in England. Several differential analyzer components in the Smithsonian collections come from a differential analyzer built after World War II by General Electric for the University of California at Los Angeles and used extensively in the design of aircraft.
