This was an attractively cheap solution within the existing technology, and had been provisionally adopted in the Draft Report on the EDVAC.
In this September 1945 period, they tried out the principle in the Hanslope hut.
Don Bayley rigged up a cardboard tube, eight inches across and the whole ten feet of the hut in length.
They connected the amplifier to a microphone at one end of the tube and a loudspeaker at the other.
The idea was simply to get a feel for the problem by recycling a sound wave in air on the delay line principle, clapping at one end and hoping to set up a hundred artificial echoes thereafter.
They did not get it to work before Alan left Hanslope to take up his NPL post, which officially began on 1 October 1945.
But it meant that he arrived full of ideas both logical and physical, and was far from being the pure mathematician of 1938.
In setting up the new Mathematics Division, Womersley had been able to recruit from the experts in the field of numerical computation, as it had been developed for the war effort.
His division took over the highly regarded Admiralty Computing Service as the nucleus of what was the most high-powered group in the western world, the rival being the American equivalent at the National Bureau of Standards.