xii TABLE OF CONTENTS 



Chapter XIV. Cryptographs and Ciphers. 



PAGE 



Authorities 292 



Cryptographs. Definition. Illustration 292 



Ciphers. Definition. Illustration 293 



Essential Features of Cryptographs and Ciphers 293 



Cryptographs of Three Types 294 



Transposition Type. The Eoute Method 294 



Use of non-significant symbols. The Grille .... 297 



Use of broken symbols. The Soytale 299 



Ciphers. Use of arbitrary symbols unnecessary 300 



Ciphers of Four Types 300 



Substitution Alphabets. Illustrations 300 



Conrad's Tables of Frequency 302 



Ciphers of the Second Type. Illustrations 303 



Shifting Alphabets. Illustrations 306 



Gronfeld's and the St Cyr Methods 306 



The Playfair Cipher 308 



Ciphers of the Fourth Type. Illustrations 309 



Desiderata in a good Cipher or Cryptograph 310 



Cipher Machines 311 



On the Solution of Cryptographs and Ciphers 311 



Example 312 



Historical Ciphers 315 



Julius Caesar, Augustus, Bacon, Morse Code .... 315 



Charles I 316 



Pepys 317 



De Bohan, Marie Antoinette 318 



The Five Digit Code Dictionary 318 



Chapter XV. String Figures. 



A world-wide Amusement of Primitive Man 321 



Construction of 321 



Typical Examples of String Figures 322 



A Mosquito or Fly (Amazon Indians) 322 



A Man Climbing a Tree (Queensland Blacks) .... 323 



Openings A, B. Navahoing 324 



A Tent Flap (Apache Bed Indians) 325 



Lightning (Navaho Indians) 326 



A Salmon Net (Caroline Islanders) 327 



The 7am Thief (Gold Coast Negroes) 328 



The Caterpillar (Polynesians) 830 



Oat's Cradle (Korea and Northern Europe) 831 



