In the late 1940s there were three well-funded computer groups in the UK: at Manchester University, Cambridge University and the National Physical Laboratory. Kathleen Britten (later Booth), who has died aged 100, was a research assistant in a fourth group, working at Birkbeck College, University of London. With minuscule funding, this group built a computer whose design provided the basis of the top-selling British computer of its era.
The computer group was part of the crystallography group at Birkbeck set up after the second world war by JD Bernal, one of the most influential scientists of his generation, and was headed by Andrew Booth, whom Kathleen would go on to marry in 1950.
They had developed much closer links to the American computer projects than to those in Britain. In 1946 Bernal had helped Andrew secure a Rockefeller Foundation grant to visit the computer project led by John von Neumann at the Institute for Advanced Study, Princeton. Von Neumann was one of the principal inventors of the modern electronic computer. Andrew paid a subsequent six-month visit in March to September 1947, this time accompanied by Kathleen.
There they divided their time, Andrew studying computer design and Kathleen programming, with the aim of building a machine to be called the Automatic Relay Calculator (ARC). On their return to Britain, work began on the ARC, which was physically built mainly by Kathleen and a colleague, Xenia Sweeting.
According to Kathleen, the machine first worked on 12 May 1948, making it the first example of the new type of “stored-program” computer to operate, although it was not electronic, and was built using electromechanical relays rather than vacuum tubes.
The ARC was quickly superseded by a faster electronic version, the Simple Electronic Computer (SEC), and that in turn by the APE(X)C – the All Purpose Electronic X-ray Computer. The machine was just about working when it was described in the Booths’ jointly written book Automatic Digital Computers, published in 1953.
The British Tabulating Machine Company (later ICL), which had given financial support to the computer group, adopted its design for a commercial data-processing computer. The machine was first sold in 1954 as the HEC (Hollerith Electronic Computer). Later, renamed the 1200 series of computers, more than a hundred were sold to various businesses, making it the UK’s top-selling computer of the 1950s.
Born in Stourbridge, Worcestershire, Kathleen was the only daughter and middle child of three of Gladys (nee Kitchen) and Frederick Britten, a tax inspector. She was educated at King Edward IV high school for girls, Birmingham, and went on to read mathematics at Royal Holloway College, University of London. After graduating in 1944, she spent two years as a junior scientific officer at RAE (Royal Aircraft Establishment) Farnborough, working on aerodynamics.
In 1946 she became a research scientist at the British Rubber Producers Research Association, which had also funded Andrew’s doctorate in X-ray crystallography, and continued to support his computer research. In the year of their marriage, Kathleen was awarded a doctorate in applied mathematics. Two years later, she joined the staff of Bernal’s crystallography group at Birkbeck College.
The Birkbeck computer group had also been partially funded by the Rockefeller Foundation for research into the machine translation of natural language. To fulfil this obligation Kathleen wrote a translation program, first demonstrated in 1955, by translating a passage of French into English. Subsequently the college became a leading centre for natural language translation. In 1958 Kathleen wrote an early textbook, Programming for an Automatic Digital Computer, and began research into neural networks, investigating the ways in which animals recognise patterns, and applied this to optical character recognition.
In 1962 the Booths decided to leave Birkbeck. According to Andrew, this was because of the college’s refusal to accept an offer from the British Tabulating Machine Company to endow a chair in computer engineering. Disenchanted by what he described as the “socialist mediocrity” of Britain, the couple took up positions at the University of Saskatchewan in Canada, where Kathleen undertook research on machine translation and neural networks. She also became an advocate for women in science and engineering.
In 1972 the Booths moved to Thunder Bay, Ontario, where Kathleen became an honorary professor at Lakeland University. Six years later they retired to Vancouver Island but maintained their links to computing by establishing a consultancy, Autonetics Research Associates.
Since 2015 what is now Birkbeck, University of London has held the annual Andrew and Kathleen Booth memorial lecture in computer science.
Andrew died in 2009. Kathleen is survived by their two children, Ian and Amanda.
• Kathleen Hylda Valerie Booth, computer scientist, born 9 July 1922; died 29 September 2022
