each case being simple. We were able to a considerable extent to dovetail them in with each other so that Porpoise could be done partly in what would otherwise have been slack time. A further help was the Porpoise habit of having 4 triplets or 3 triplets and a quadruplet in the month (triplet = 3 successive days on the some W.O.). Improved methods and increased proportion of genuine traffic on Dolphin was making Banburismus steadily easier and we again began to find ourselves under worked; we now began to reduce our skilled staff, a process that was continued until from 16 in February 1942 we went down to 4 in August 1944. This staff reduction was fully justified by events and was thoroughly sound policy. Nothing is more demoralizing than "ticking over" with barely enough to keep one busy; not only is it very trying for those concerned but people tend to get generally slack and what work there is gets badly done. If anything, we did not reduce our skilled staff soon enough.
6. In October Perkins and Bolombek were transferred to Twinn's section and in November Yoxall went to Naval Section to work on J.N. 157 machine leaving as memorial "Yoxallismus" the name always given in the Hut to the E-rack used on Offizier.
7. Also in November Turing left the section for a visit to America. Although this did not mark the official end of his connection with the section he never did any more work in it and therefore it is a fitting place to recognize the great contribution that he made. There should be no question in anyone's mind that Turing's work was the biggest factor in Hut 8's success. In the early days he was the only cryptographer who thought the problem worth tackling and not only was he primarily responsible for the main theoretical work within the Hut (particularly the developing of a satisfactory scoring technique for dealing with Banburismus) but he also shared with Welohman and Keen the chief credit for the invention of the Bombe. It is always difficult to say that anyone is absolutely indispensable but if anyone was indispensable to Hut 8 it was Turing. The pioneer work always tends to be forgotten when experience and routine later make everything seem