Another short (120 Pages) but very interesting insight to the breaking of the German Enigma code during World war II. This is my third such book and the difference with this one is it provides a lot more detail of the pre war breaking of Enigma. As with the others its very interesting stuff.
It deals not only with the introduction of the commercial machine and then the breaking of German version back in the early 1930's but also the the interesting aspect of were they got the intelligence that helped them break the code. The German that fed the information to the French intelligence is covered and the amazing fact the French Office had to go rounding touting this information to countries to find someone interested in using it. Embarrasingly the Brits and French weren't interested at that point. Fortunately the Poles where and made good use of it.
How the the Poles code breaking is fed to the Brits and French, when war is imminent, is covered and is equally interesting and almost as embarrasing.
The authors contribution to code breaking at Bletchley Park, Herivelismus or the Herivel Tip, is covered towards the end and makes fascinating reading. Its amazing to see how the code breaking of these machines had so much to do with human error in there operational use.
I've been a bit mean and only given the book fours stars. Its well written and superbly interesting but it's only got four as the thrust of the books name Herivelismus is only covers a small part of the book, about 30 pages, and seemed meaningless for the first 80/90 pages.