Secret & Urgent The Story of Codes & Ciphers,by Fletcher Pratt,1942 , grubby dustwrapper,otherwise a very good copy.282 pages. Superb old book on the use of codes in warfare,contains masses of coding methods,illustrated and explained. http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&sspagename=STRK%3AMESE%3AIT&viewitem=&item=320110515499&rd=1&rd=1
