314 CRYPTOGRAPHS AND CIPHERS [CH. XIV 



In the second line no letter occurs more than once, so we 

 get no clue from Conrad's Table. This could not happen if the 

 message were of any considerable length. 



In the third line p occurs twice, and s twice. Hence, as 

 before, we must make p and s successively stand for the letters 

 e, t, a, o, i, n, s, r, h. These give respectively = 11, 22, 15, 1, 

 7, 2, 23, 24, 8, and = 14, 25, 18, 4, 10, 5, 0, 1, 11. Altogether 

 this gives us 16 systems for the representation of this line. 

 Obviously the most probable hypothesis is that where 0=11, 

 p = e, s = h, or that where 6 = 1, p = o, and s = r: these give for 

 the third line either h, j, k, e, h, e, d, or r, t, u, o, r, o, n. 



In the fourth line i occurs three times. As before, make i 

 stand successively for e, t, a, o, i, n, s, r, h. Of these the first, 

 where 6 = 4, is the most probable. The slip corresponding to 

 this is r, i, e, r, e,f, e. 



Now try combinations of these slips each in its proper line 

 until, when we read the message in columns, we get the begin- 

 ning of a word; if words appear in more than one column it is 

 almost certain that we are right. We begin by taking the 

 five slips which are indicated as being specially probable. The 

 slip in the first line derived from 6 = 6, the slip in the third 

 line derived from 0=1, and the slip derived from = 4 in the 

 fourth line give w . rra . tis . ued . ora . res . ofj . nes, and of course 

 the solution is obvious. The key number was 6814, and the 

 message is deciphered by using 6814 backwards. The corre- 

 sponding St Cyr key word is gibe. The message was Warrant 

 issued for arrest of Jones. 



If the combination of the slips is troublesome we can some- 

 times get assistance by choosing those combinations which make 

 the recurring pairs of letters (here vg and ij) represent pairs 

 which occur in Conrad's Table. Also the occurrence of double 

 letters in the cipher will often settle what combinations of slips 

 are possible. 



It may be said that this is a tedious operation. Of course 

 it is. Deciphering is bound to be troublesome, but a great 

 deal of the work can be done by unskilled clerks working under 

 the direction of experts. The longer the message, the fewer the 



