Encyclopaedia Britannica, or, a Dictionary of arts, sciences, and miscellaneous literature : enlarged and improved. Illustrated with nearly six hundred engravings > Volume 6, CHI-Crystallization

C I P [ 160 1 C I R
Cipher, ver : thougli as all ciphers depend on the combination
v——' of letters, there are fcarce any that may not be decipher¬
ed with time and pains; as we lhall ihow further on.
Thofe ciphers are the beft that are by their nature moll
free from fufpicion of being ciphers $ as for example,
if the letters were there written with fympathetic ink,
the cards might then pafs for a common pack.
II. By a dial. On a piece of fquare pafteboard
ABCD, fig. 3. 4. draw the circle EFGH, and divide
it into 26 equal parts, in each of which muft be writ¬
ten one of the letters of the alphabet.
On the infide of this there muft be another circle of
pafteboard, ILMN, moveable round the centre O, and
the extremity of this muft be divided into the fame
number of equal parts as the other. On this alfo muft
be written the letters of the alphabet, which, however,
need not be difpofed in the fame order. The perfon with
whom you correfpond muft have a fimilar dial, and at the
beginning of your letter you muft put any two letters
that anfwer to each other when you have fixed the dial.
Exam. Suppofe you would write as follows : “ If
you will come over to us, you (hall have a penfion, and
you may ftill make a (ham oppofition.” You begin
with the letters Ma, which (how how the dial is fixed :
then for If you, you write un juc, and fo for the reft,
as you fee at fig. 6.
The fame intention may be anfwered by a ruler, the
upper part of which is fixed, and the lower part made
to Hide ; but in this cafe the upper part muft contain
two alphabets in fuceeflion, that fome letter of that part
may conftantly correfpond to one in the lower part.
The divifions (landing direflly over each other in a
ftraight line will be much more obvious than' in the
circumference of a circle. Or two ftraight piecys of
pafteboard regularly divided, the one containing a (in¬
gle, and the other a double alphabet, would anfwer ex-
aftly the fame purpofe. In this cafe a blank fpace may
be left at each end of the (ingle alphabet, and one or
two weights being placed on both the pieces will keep
them fteady.
III. The correfponditig/paces. Take two pieces of
pafteboard or ftiff paper, through which you muft cut
long fquares, at different diftances, as you will fee in
the following example. One of thefe pieces you keep
yourfelf, and the other you give to your correfpondent.
When you would fend him any fecret intelligence, you
lay the pafteboard upon a paper of the fame fize, and
in the fpaces cut out, you write what you would have
underftood by him only, and then fill up the interme¬
diate fpaces with fomewhat that makes with thofe words
a different fenfe.
jT lhall bej much obliged to you, as reading [ alone j
.engages my attention |at| prefent, if you will lend me
any one of the jeightj volumes of the Spectator. I
hope you will excufe jthisj freedom, but for a winter’s
[evening] I ]dontf know a better entertainment. If I
jfaiT| to return it foon, never truft me for the time
(to come.]
A paper of this fort may be placed four different
ways, either by putting the bottom at the top, or by
turning it over j and by thefe means the fuperfluous
words may be the more eafily adapted to the fenfe of Cipher
the others. ||
This is a very eligible cipher, as it is free from fu- ^‘rcaffi».
fpicion, but it will only do for (hurt meffages ; for if
the fpaces be frequent, it will be very difficult to make
the concealed and obvious meanings agree together ;
and if the fenfe be not clear, the writing will be liable
to fufpicion.
IV. The tmtjical cipher. The conftruftion of this
cipher is limilar to that of N° II. The circle EFGH
(%* 3*) *s to b® divided into twenty-fix equal parts j
in each part there muft be written one of the letters
of the alphabet, and on the anterior circle ILMN,
moveable round the centre O, there is to be the fame
number of divifions : the circumference of the inner-
circle muft be ruled in the manner of a mufic paper ;
and in each divilion there is to be placed a note, dif¬
fering either in figure or pofition. Laftly, within the
mufical lines place the three keys, and on the outer
circle, the figures that are commonly ufed to denote
the time.
Then provide yourfelf with a ruled paper, and place
one of the keys, as fuppofe that of ge re fol, againft the
time two-fourths at the beginning of the paper, which
will inform your correfpondent how to fix his circle.
You then copy the notes that anfwer to the feveral let¬
ters of the words you intend to write, in the manner
expreffed at fig. 5.
A cipher of this fort may be made more difficult to
difcover by frequently changing the key, and that will
not in the leal! embarrafs the reader. You may like-
wife add the mark $ or h to the note that begins a
word, which will make it more eafy to read, and at
the fame time give the mufic a more natural afpe<ff.
This cipher is preferable to that of N° II. above, as it
may be inclofed in a letter about common affairs, and
pafs unfufpefled.
CIPUS, in antiquity, a low column, with an infcrip-
tion, erected on the high roads, or other places, to (how
the way to travellers j to ferve as a boundary j to mark
the grave of a deceafed perfon, &c.
CIR, St, a village of France, two miles from Ver-
failles, which was remarkable for.a nunnery founded
by Louis XIV. The nuns were obliged to take care
of the education of 250 girls, who could prove their
families to have been noble from the 4th generation on
the father’s fide. 1 hey could not enter before hj, nor
after 12 years of age; and they continued till they
were 20 years and three months old. The houfe was
formerly a moft magnificent ftru&ure.
CIRC/EA, Enchanter’s Night-shade. See Bo¬
tany Index.
CIRCASSIA, a large country of Alia, fituated be*
tween 45 and 50 degrees of north latitude, and be¬
tween 40 and 30 of eaft longitude. It is bounded by
Ruffia on the north ; by Aftracan and the Cafpian fea
on the eaft ; by Georgia and Dagiftan on the fouth ;
and by the river Don, the Palus Mseotis, and the Black
fea, on the weft. Ihis country has long been cele¬
brated for the extraordinary beauty of its women ; and
here it was that the practice of inoculating for the
fmallpox fir ft began. Terki, the principal city, is
feated in a very fpacious plain, very fwampy, towards
the fea-fide, in 430 23' north latitude : it is about
three werfts in compafs, well fortified with ramparts
and