Andrew D. Booth – Britain’s Other “Fourth Man” - History of Computing: Learning from the Past - page 27

2 Relay Computers
Andrew Booth first met the challenge of solving complex sets of equations while
working on the X-ray structure of explosives during World War 2. In 1975 in an in-
terview with Christopher Evans for the Science Museum, London [1] he related how
during the war he managed a small team of girls doing these calculations and being by
temperament a mathematician I don't like arithmetic. …. I didn't think much of the
methods they were using and I tried to do two things. In the first place. I devised some
better mathematical methods … but I also made one or two small hand calculators.
His father was a marine engineer and part time inventor. Consequently it was per-
haps not surprising that Andrew Booth developed mechanical devices to reduce the
need for laborious calculation by hand of solutions to sets of equations for their many
observations.
Fig. 1. Kathleen Britten, Xenia Sweeting and Andrew Booth working on ARC in December
1946
It was this latter interest that brought him to the attention of the great crystallogra-
pher J D Bernal. Returning to Birkbeck College in the University of London at the
end of WW2, Bernal started building a new research group to study crystallography.
He decided to appoint four assistants, one of whom was to lead on mathematical
methods. He appointed Andrew Booth who had completed a PhD on crystal structures
of explosives at Birmingham in 1944. Andrew Booth started by building analogue
devices and exploiting other mechanical devices as he outlined in his first book [2].
Shortly after his arrival at Birkbeck he started to build his first electromechanical
calculator, the Automatic Relay Calculator (ARC) , shown in Figure 1. Due to a lack