Out of one hundred and one recurring pairs we have fifty with the factors 2×3=6; out of twelve recurring triplets, nine have these factors; and the four recurring groups of four or more letters all have these factors. The percentages are respectively 49.5%, 75% and 100% and we may be certain from this that six alphabets were used. But, before the six frequency tables are made up, there is one more point to be considered; why are there so many recurring groups which do not have six as a factor? The answer is that one or more of the alphabets is repeated in each cycle; that is, a key word of the form HAVANA has been used. If this were the key word, the second, fourth and sixth alphabets would be the same. We will see later that in this example the second and sixth alphabets are the same and this introduces the great number of recurring groups without the factor 6. We will now proceed to make a frequency table for each alphabet. As the message is written in thirty columns, we take the first, seventh, thirteenth, etc., as constituting the first alphabet; the second, eighth, fourteenth, etc., as constituting the second alphabet and so on. The prefix and suffix letter is noted for each occurrence of each letter. The importance of this will be appreciated when the form of the frequency tables is examined. None bears any resemblance to the normal frequency table except that each is evidently a mixed up alphabet. The numbers after "Prefix" and "Suffix" refer to the alphabet to which these belong, for convenience in future reference. Frequency Tables First Alphabet Letter Prefix (6) Suffix (2) A 111 3 DUD ESF B 11111111 8 OOOFEEOS EOESYSCY C 0 D 1111 4 TYT DJUD E 1 1 E S F 0 G 0 H 0 I 11111111 8 EOFFEOVS OSEFQYJ J 0 L 1 1 O J M 1 1 F O N 1111 4 FEDU EEEE O 1 1 E O P 11 2 GE ND Q 1111 4 UEOE OFBB R 1111111 7 EEEYYBB GSGOOEE S 1 1 D V T 11111111 8 JUJMQYVF LDSBPQDT U 0 V 11 2 UF MS X 111111 6 YQTQQA QUQDYQ Y 1 1 O E Z 111 3 UUM JHU Second Alphabet Letter Prefix (1) Suffix (3)