7 AUGUST 1964, Page 15


1R,—Alan Brien (July 24) includes computers in his list of American innovations which have eventually become domesticated here. In fact, seven men de- veloped the electronic computer, all of them English, all working in England :

Francis Bacon, who, during the reign of Elizabeth [, revived the idea of binary arith- metic, i.e., using only the figures 0 and 1 (and not, as almost invariably stated, the German Leibniz, who was not born until twenty years after Bacon was dead).

Charles Babbage, who, during the reign of Queen Victoria, invented the Analytical En- gine* (not to be confused with his earlier and better-known Difference Engine), but reverting to denary arithmetic.

Eccles and Jordan, who, in 1919, demonstrated that a thermionic valve could be in either of two stable states, and made to change from one state to another with the speed of light, but did not succeed in coming to the notice of the arithmeticians.

Wynn-Williams, who, in 1931, published de- signs for using electronic valves for counting devices, with no mechanical moving parts.

William Phillips, who put these ideas (and some others) together, and designed a simple electronic computer in 1934, offered the pro- visional patents to HMG as a free gift in 1935, and described his ideas to the Institute of Actuaries in January, 1936, in a paper entitled Binary Arithmetic, illustrated by a mechanical analogue to show how a computer, working in- visibly, would deal with the difficulty of the `carry-forward' in binary.*

John Womersley, who began to assist Phillips in March, 1943, to design what eventually be- came the Ace Prototype Computer.* A. M. Turing, who, having written a paper joined Phillips Computable Numbers during 1937, oined Phillips and Womersley in the autumn of 1945.

Incidentally, when at the end of the war the Americans at Harvard and MIT began to make elec- tronic computers, they got off on the wrong foot, using denary, and did not switch to binary until after ENIAC and Harvard 1 and II were constructed.

24 Clifford's Inn, Fleet Street, EC4

'All three are now together in the Science Museum, South Kensington.