SIG 
answer: and then every ship is to endea- 
vour to come up with, and board the 
enemy. Wheh he would have the chase 
given over, he hoists a white-flag at the 
fore-top-mast head, and fires a gun. If he 
would have the red squadron draw into a 
line of battle, one a-breast of another, he 
puts abroad a flag striped red and white on 
the flag-staff at the main-top-mast-head, 
with a pendant under it, and fires a gun: if 
the white or second squadron is to do so, 
the flag is striped red, white, and blue : if 
the blue or third squadron is to do so, the 
flag is a Genoese ensign and pendant : but 
if they are to draw into a line of battle one 
a-head of another, the same signals are 
made without a pendant. If they are to 
draw into the line of battle one a-stern ot 
another, with a large wind, and he would 
have the leaders go with the starboard-tacks 
aboard by the wind, he hoists a red and 
white flag at the mizen-peek, and fires a 
gun : but if they should go by the larboard- 
tacks aboard the wind, he hoists a Genoese 
flag at the same place: which signals, like 
others, must be answered by the flag-ships. 
Signals, day, are usually made by flags 
and pendants, sometimes accompanied with 
one or more guns ; and night-signals are 
either lanterns disposed in certain figures, 
as lines, squares, and triangles, or are made 
with false fires. Fog-signals consist of ope- 
rations which emit sound, as firing cannon 
or muskets, beating drums-, &c. 
Signals, in military actions.'' Informer 
times large pieces of wood were hung above 
the towers of cities or castles, which, by be- 
ing drawn up or lowered, gave intelligence 
of what passed. This method has been suc- 
ceeded by the invention of telegraphs, 
which answer every purpose of communica- 
tion, when they can be established through 
any extent of .country. Besides those sig- 
nals, there are others which may be called 
vocal and demi-vocal. The vocal signals 
are those of the human voice, which con- 
sist in the necessary precautions that are 
adopted to prevent a guard or post from 
being surprised, to enounce words of com- 
mand in action, &c. Of the first descrip- 
tion are paroles and countersigns, which are 
exchanged between those to whom they are 
intrusted, and which are frequently altered, 
during the -day and night, to prevent the 
enemy from receiving any information by 
means of spies. The demi-vocal signals are 
conveyed by military instruments ; the dif- 
ferent soundings of which indicate, instan- 
taneously- wUpther an army is to halt or to 
SIL 
advance, whether troops are to confmue 
in the pursuit of an enemy, or to retreat. 
The demi-vocal signals, directed to be 
observed in the British service, as far as 
regards the manoeuvring of cor'vs, &c. con- 
sist of signals for the goveri.-nent of light 
infantry, and of cavalry regiments, squa- 
drons, or troops : the latter are properly 
called soundings. Light infantry signals are 
to give notice to advance, to retreat, to 
halt, to cease firing, to assemble, or call in 
all parties. In the regulations printed by 
authority it is observed, that these signals 
are to be always considered as fixed and 
determined ones, and are never to be 
changed. The bugle horn of each company 
is to make himself perfect master of them. 
All signals are to be repeated ; and all those 
signals which are made from the line or co- 
lumn, are to convey the intention of the 
commanding oflicer of the line to the offi- 
cer commanding the light infantry, who will 
communicate them to the several compa- 
nies or detachments either by word or sig- 
nal. 
SIGNATURE, in printing, is a letter 
put at the bottom of the first page at least, 
in each sheet, as a direction to the binder, 
in folding, gathering, and collating them. 
The signatures consist of the capital letters 
of the alphabet, which change in every 
sheet : if there be more sheets than letters 
in the alphabet, to the capital letter is 
added a small one of the same sort, as A a, 
B b ; which are repeated as often as neces- 
sary. In large volumes it is usual to distin- 
guish the number of alphabets after the 
first two by placing a figure before the sig- 
nature, as 3 B, 4 B, &c. 
SIGNET, one of the king’s seals, made 
use of in sealing his private letters, and all 
grants that pass by bill signed under his 
majesty’s hand : it is always in the custody 
of the secretaries of state. 
SILENE, in botany, catch-Jty, a genus 
of the Decandria Trigynia class and order. 
Natural order of Caryophyllei. Caryophyl- 
leae, Jussieu. Essential character : calyx 
ventricose ; j)etals five, with claws, crowned 
at the throat; capsules three- celled. There 
are sixty-six species. 
SILICA, in mineralogy and chemistry, 
is generally found in a stony state, and from 
its forming nearly the entire composition of 
flint, it has acquired the name of silica, 
silex, or siliceous earth. This earth exists 
in great abundance in nature, and it con- 
stitutes the basis of some of the hardest 
stones of which the nucleus of the globe 
