ABSTRACT
Charles Babbage invented two calculating machines, the Difference Engine and the Analytical Engine. Of the two, the Difference Engine was, historically and technically, the less interesting- although it was the machine that came closest to actually being built. Babbage never built a full-scale Difference Engine because in 1833 he abandoned it for a new invention, the Analytical Engine, the chief work on which his fame in the history of computing rests. Between 1834 and 1846, without any outside financial support, Babbage elaborated the design of the Analytical Engine. Differential analyzers and network analyzers worked well for a limited class of engineering problems: those for which it was possible to construct a mechanical or electrical model of the physical system. A whole new generation of analog computing machines was developed in the 1920s to help design the rapidly expanding US electrical power system.
