Died: 8 January 1980 in Ambler, Pennsylvania, USA

John Mauchly grew up in Chevy Chase, Maryland. He went to school in Washington DC where his father was employed as a physicist in the Department of Terrestrial Magnetism at the Carnegie Institute. In 1925 John was awarded a scholarship by the State of Maryland to allow him to attend Johns Hopkins University in Baltimore, Maryland. He began studying engineering at Johns Hopkins but his interests changed in the course of his studies towards pure science and his first degree was in physics.

Mauchly continued studying physics after taking his first degree and he was awarded his doctorate in 1932. He then taught physics at a number of different colleges and spent some time at the Carnegie Institution in Washington DC undertaking research on analysing the weather. He soon realised that to make weather forecasts it was necessary to reduce large amounts of data very quickly, and he began to look for mechanical help in making such computations.

By 1940 Mauchly was teaching physics at Ursinus College near Philadelphia. While there he became interested in developing electronic computers which combined his interests in physics and engineering. It may seem strange today that someone with an interest in engineering would be drawn towards building computers but at this time a computer was a huge mechanical construction. Also Mauchly's interests were in electrical engineering and he looked for ways to develop electrical circuits for computation.

Work was going on in the area of producing electrical circuits to do arithmetic and Mauchly, together with some of his students from Ursinus College, visited establishments where such developments were being undertaken. Mauchly began to experiment in constructing electrical circuits for counting while at Ursinus College, aimed at trying out new ideas which he brought to the subject.

Now 1941 was the time when World War II was strongly affecting the directions of academic research as the USA geared up for research specifically directed towards the war effort. Mauchly took a training course in electronics, designed for defence purposes, at the Moore School of Electrical Engineering at the University of Pennsylvania. Having completed the course Mauchly was offered a position as an instructor on the course.

Research at the Moore School of Electrical Engineering was being carried out using early forms of computers. In particular the School used a Bush analyser, designed by Vannevar Bush specifically to integrate systems of ordinary differential equations. The machine consisted of replaceable shafts, gears, wheels, handles, electric motors, and disks and required much manual work to set it up. Mauchly found that [3]:-

When large and related problems that could be set on the machine for weeks were to be solved it was in constant use, but when small problems were being dealt with, engineers found it more expedient to solve then mathematically, without taking days to set up the machine.

Mauchly had already developed his own ideas on how to construct a better computer and he tried to interest other members of staff at the Moore School but with little success. One person who was interested in his ideas, however, was John Eckert who had been one of his instructors at Moore College when Mauchly had been a student on the training course. The two became close friends and discussed their ideas about electronic computers at almost every possible opportunity. Mauchly wrote a report on the design of an electronic computer which would, in his opinion, be far easier to use and allow results to be obtained much more quickly than the Bush analyser.

The Ballistic Research Laboratory had been set up at Aberdeen, in Harford county, northeastern Maryland as part of the Aberdeen Proving Ground, a military weapons testing site which had been established in 1917 during World War I. The Ballistic Research Laboratory consisted of staff from the Moore School and staff from the Aberdeen Proving Ground. When a new director was put in charge of the Ballistic Research Laboratory in 1942 he worked both at Aberdeen and at the Moore School. He read Mauchly's report in March 1943, eighteen months after it was written, and was very impressed. Various committees then considered the proposal before money could be assigned to the project of building Mauchly's computer, and in April 1943 Veblen approved the scheme.

Mauchly and John Eckert then collaborated in the construction of the Electronic Integrator and Computer (ENIAC). The machine was intended to be a general purpose one, but it was also designed for a very specific task, namely compiling tables for the trajectories of bombs and shells. ENIAC is described in [1]:-

Completed by February 1946, the ENIAC was the first general-purpose electronic digital computer. It contained roughly 18000 vacuum tubes and measured about 2.5 metres in height and 24 metres in length. The machine was more than 1000 times faster than its electromechanical predecessors and could execute up to 5000 additions per second. Its operation was controlled by a program that was set up externally by wires on plugboards. The ENIAC was the most complex and influential electronic computer of its time ...

Of course by 1946 World War II was over but the machine was used intensively, particularly on top secret problems associated with the development of nuclear weapons. Von Neumann was working on this project and became involved with the ENIAC computer and used it to solve systems of partial differential equations which were crucial in the work on atomic weapons at Los Almos.

Both Mauchly and John Eckert left the Moore School at the University of Pennsylvania in October 1946. They started up the Electronic Control Company which received an order from Northrop Aircraft Company to build the Binary Automatic Computer (BINAC). One of the major advances of this machine, which was used from August 1950, was that data was stored on magnetic tape rather than on punched cards.

The Electronic Control Company become the Eckert-Mauchly Computer Corporation and it received an order from the National Bureau of Standards to build the Universal Automatic Computer (UNIVAC). This was the first computer to be produced commercially in the United States with 46 UNIVACs being built. One of the major advances which the UNIVAC introduced was an ability to handle both numerical and alphabetical information with equal success.

John Eckert and Mauchly were better at computer design than they were at the economics of running a company. The problem really lay in the fact that this was such a new area that costs of production were extremely hard to estimate. As a consequence the Eckert-Mauchly Computer Corporation soon hit financial difficulties. In 1950 the Remington Rand Corporation acquired the Eckert-Mauchly Computer Corporation and changed its name to the Univac Division of Remington Rand.

Mauchly left the company and formed Mauchly Associates of which he was president from 1959 to 1965 when he became chairman of the board. In 1966 Mauchly received the Harry M Goode Memorial Award, a medal and $2,000 awarded by the Computer Society:-

For his pioneering contributions to automatic computing by participating in the design and construction of the ENIAC, the world's first all-electronic computer, and of the BINAC and the UNIVAC, and for his pioneering efforts in the application of electronic computers to the solution of scientific and business problems.

1. Biography in Encyclopaedia Britannica. 
   http://www.britannica.com/eb/article-9051476/John-W-Mauchly

Articles:

1. F Gareth Ashurst, Pioneers of computing (London, 1983), 109-126.
2. T Atherton, J W Mauchly and J P Eckert : the men who built ENIAC, Electronics world and wireless world 96 (1990), 541-543.