CYPHER. 
"by writing in such a manner' as shall be 
legible only to those who are acquainted 
with the rules by which the characters made 
use of are formed or disposed. It is prin- 
cipally used in diplomatic correspondence, 
or on other national affairs, such as those 
relating to the operations of war. As the 
nature of alphabetic writing, and the struc- 
ture of languages necessarily imply certain 
indispensable habitudes of the letters and 
words, it often happens that the laws or 
conditions made use of for the sake of 
secrecy can be detected by skilful persons, 
and the secret by that means discovered. 
The art of discovering the sense of writings 
of the description here mentioned, is called 
decyphering. 
One of the most obvious methods of disguis- 
ing the alphabet will consist in changing the 
characters. Thus, for example, if the Eng- 
lish language were written in Greek charac- 
ters, it would not be legible by a person 
unacquainted wdth them ; or if the English 
alphabet were to be transposed, as by tak- 
ing every consequent letter for its antece- 
dant, namely, b for a, c for h, d for c, &c. ; 
or by any other rule of arrangement the same 
consequence would follow, and the vniting 
would be secret, unless the sagacity of the 
reader should enable him to develope the 
conditions; which in the cases here men- 
tioned it would not be difficult to do. 
■ From tlie comparative facility of decy- 
phering writings, made in a disguised single 
alphabet, it became necessary to use con- 
trivances of less simplicity. By substitut- 
ing figures in the place of letters, and by 
using more than one figure to denote each 
letter ; and, in addition to this, by adopting 
a considerable number of distinct charac- 
ters, letters, or combinations of figures, for 
each letter of the alphabet, the difficulty of 
decyphering may be prodigiously augment- 
ed. Thus, for example, if a table were 
made consisting of twenty-four vertical 
columns, having a letter of the alphabet at 
the head of each; and six distinct ranges of 
«liaracters were placed on horizontal lines 
beneath; and, in particular, if a greater 
number of characters were allowed for the 
vowels, in proportion to their frequency of 
recurience; and, if in writing, each range 
be used in succession, the developement of a 
communication thus made would be ex- 
tremely difficult. Or, otherwise, if a square 
of twenty-five compartments be made re- 
sembling the multiplication table, but con- 
taining the 'letters of the alphabet ; and the 
first five digits be placed over the top row 
and down the side, each letter may be 
denoted by the two figures which stand op- 
posite the same, namely, at tlte top and the 
side, as in the table beneath. 
1 
2 
S 
4 
5 
a 
/ 
k 
P 
V 
b 
g 
1 
r 
w 
c 
h 
m 
s 
X 
d 
i 
n 
t 
y 
e 
j 
0 
u 
Z 
In this manner, the letter a will be de- 
noted by 11, and the letter b by 12, the 
letter n by 34, and the letter u> by 52, &c. ; 
and as it is advantageous, in every kind of 
cypher, that the words should not be writ- 
ten from each other, or with spaces be- 
tween, but that every line should be conti- 
nuous tliroughout, the other digits, namely, 
67890 may be used to denote blank spaces. 
It is manifest also that if there were four or 
five of these tables ; each containing the al- 
phabet in a different order of arrangement, 
and the several lines of the intended commu- 
nication were to be written, in succession, 
according to each of the tables respective- 
ly, the task of decyphering would be great- 
ly enhanced. 
In fact, it does not appear difficult to 
contrive a multiplicity of cyphers which 
shall be beyond the reach of human skill to 
develope, otherwise than by some fortuitous 
circumstance or happy observation, not de- 
pendent upon rule ; but at the same time it 
must be observed that most of those cy- 
phers which are tlie most difficult of disco- 
very are also tedious, and not unffequently 
difficult in the use. 
For the sake of brevity we pass over the 
variety of arbitrary marks, which may be 
substituted for tlie letters of the alphabet or 
for intire words; such as a single dot or 
right line, or unvaried character, deriving 
its distinct significance from its several po- 
sitions with regard to ruled lines or spaces 
on the paper ; which lines may either be 
actually drawn or apparent, or else their 
places may be indicated by dots or other 
marks to enable the reader himself to draw 
them. 'Writing, by means of the charac- 
ters of music, comes under this class ; and 
the telegraphic signals now so generally 
adopted may be referred to those arbitrary 
combinations of dots which signify letters 
or words. And when the notion of these 
combinations has once been clearly appre- 
Gg 2 
