zo 212 Index 407 Churchill, Winston 17, 213 Chutzpah 86 ciphers 215, 218 circle free 243 Clauser, John 333 Clay Mathematics Institute 167, 196, 225 Cleese, John 270, 303 clocks 42 astrological clock 39, 42 modern computers and 43 code breakers 211 codes 214 and children’s games 214 and code books 215 an