Differential Analyzer (Mechanical Computer) – Philadelphia PA

Description

In 1934-1935, the Moore School of Electrical Engineering at the University of Pennsylvania built a differential analyzer, an early type of computer. Designed by Oscar Schuck, it was the second of its kind – the first differential analyzer was constructed at the Massachusetts Institute of Technology in 1931. Funds and skilled labor (for example, electricians and instrument makers) came from the Civil Works Administration (CWA) and the Federal Emergency Relief Administration (FERA).

A government report from Pennsylvania described the differential analyzer: “The machine weighs 3-1/2 tons. It is approximately 30 feet long, 10 feet wide and 5 feet high. It contains 37,761 separate parts, in which are included 1,100 complete sets of ball bearings. The Analyzer has ten integrators (the heart and brains of the outfit)—four more than the first machine which was developed at the Massachusetts Institute of Technology. Seven electric motors with intricate wiring and control devices are required” (1934-1935 FERA report).

The differential analyzer was capable of solving complex math problems in just a few minutes – problems that previously would have taken a small team of mathematicians weeks or months to solve. Dr. Charles Fawcett, professor of electrical engineering at the University of Pennsylvania, further explained the machine’s capabilities: “[It] will not only solve various related mathematical equations, but will ‘memorize’ the results, solve other variables in the equation and then reach back in its memory and give accurate answers” (Clarion-News, 1934).

The New Deal-funded differential analyzer was a mechanical, or analog, computer, utilizing “gears, wheels and mechanical amplifying mechanisms” (Clarion-News, 1934), which helped pave the way for the modern digital computer. The success of the differential analyzer “resulted in contract work for various University departments, private companies, and government agencies” (UPenn Archives) and hastened the development of more complex mechanical calculators, electrical computers, and, ultimately, digital computers.

In fact, the Moore School of Engineering at the University of Pennsylvania was a hotbed of early computing technology and subsequently developed the first digital computer, the ENIAC, in 1945.

The differential analyzer built with the help of the New Deal was, in short, a stepping-stone to the machines of the electronic/digital age, “From our smartphones, touch screens, and tiny cameras to our automobiles, airplanes and medical equipment” (UPenn Engineering).

After several inquiries in May 2022, we were unable to determine whether the differential analyzer still exists.  Chances are it does not.