SIG 
jaost permanently valuable of all the senses. 
*rhe information obtained by the touch is 
acquired slowly ; and the sensations must 
be continually repeated, in order to acquire 
information respecting new objects ; but 
the sight takes in a vast variety of objects, 
and, almost at a glance, can distinguish most 
that is necessary to be known respecting 
them. Its sensations recall the past im^ 
pressions derived from the touch, and at 
once suggest the size, the shape, the dis- 
tance. of their various objects. “ If a man, 
says Reid, “ were by feeling to find out the_ 
figure of the Peak of Teneritfe, or even ot 
St. Peter’s at Rome, it would be the work 
of a lifetime.” Besides, its discovery reaches 
further than the touch could carry us ; it 
enables tis to range through the vault of 
Heaven, and determine the motions of the 
Jieavenly luminaries. It traces in the coun- 
tenance the workings of the mind ; it dis- 
plays the passions and affections of the soul. 
M’ith association it is every thing ; without 
it, it would be useless as the bright fleeting 
visions of sleep. 
Sights of a quadrant, &c. thin pieces of 
brass, raised perpendicularly on its side, or 
on the index of a theodolite, circumferentor, 
&c. They have each an aperture, or slit, 
up the middle, through which the visual 
rays pass to the eye, and distant objects are 
seen. 
SIGN, in algebra, denotes a symbol or 
character. Mr. Maclaurin observes, that 
the use of the negative sign, in algebra, is at- 
tended with several consequences that at 
first sight are admitted with difficulty, and 
has somefimes given occasion to notions 
that seem to have no real foundation. This 
sign implies that the real value of the quan- 
tity represented by the letter to which it is 
prefixed, is to be subtracted ; and it serves 
with the positive sign, to keep in view 
what elements or parts enter into the com- 
position of quantities, and in what manner, 
whether as increments or decrements, (that 
is, whether by addition or subtraction) 
which is of the greatest use in this art. See 
N EGATivE sign. 
Signs, in astronomy. The ecliptic is 
usually divided, by astronomers, into 12 
parts, called signs, each of which of course 
contains 30 degrees. They are usually 
called the signs of the zodiac ; and be- 
ginning at the equinox, where the Sun in- 
tersects and rises above the equator, have 
these names and marks, Aries vf, Taurus y , 
Gemini n, Cancer SB, Leo S\,, Virgo ng, 
Jjibra =2=, Scoipio ITL, Sagittarius Ca- 
SIG 
pricornus VJ, Aquariusun S!?, Pisces X- Of 
these signs, the first six are called northern, 
lying on the north side of the equator ; the 
lasf six are called southern, being situated 
to the south of the equator. The signs 
from Capricornus to Gemini are called as- 
cending, the Sun approaching or rising to 
the north pole while it passes through them 5 
and the signs from Cancer to Sagittarius 
are called descending, the Sun, as it moves 
through them, receding or descending from 
the north pole. See Zodiac. 
Sign manual. The King’s signature is so 
called. All commissions in the regular army 
of Great Britain, army warrants, &c. bear 
the sign manual. The appoinments of of- 
ficers in the volunteers have been so distin- 
guished during the present w'ar. Adjutants 
only in the militia have their commissions 
signed by the King ; those of the field 
officers, captains, and subalterns, &c. are 
signed by the lords lieutenants of counties, 
or by their deputies for the time being, 
sanctioned by a previous intimation from 
the Secretary of State, that the King does 
not disapprove of the names which have 
been laid before him. 
SIGNALS, certain signs agreed upon, 
for suddenly conveying intelligence to 
places, to which the voice cannot reach. 
Thus, in some countries, fires are lighted 
upon the hills, at the approach of danger : 
and at the beginning of a battle or an at- 
tack, signals are usually made with drums 
and trumpets. At sea they are given by 
firing cannon, or muskets; by lights, flags, 
sails, &c. 
Signals ^t sea are made by the admiral or 
commander in chief of a squadron, either 
in the day, or by night, whether for sailing, 
fighting, or the better security of the mer- 
chant ships under their convoy : these are 
very numerous and important, being all ap- 
pointed and determined by the Lords of 
the Admiralty, and communicated in the 
instructions sent to the commander of 
every ship of the fleet or squadron, before 
their putting to sea. Some of the principal 
of which are as follow : when a commander 
in chief would have them unmoor, he looses 
his main- top-sail, and fires a gun, which, in 
the royal navy, is to be answered by every 
flag ship, and every ship is to get under sail 
as soon as she can. When, in bad weather, 
he would have them wear, and bring to the 
other tack, he hoists a pendant on the cn- 
sign-staif, and fires a gun : then the leeward- 
most and stern-most ships are to wear first, 
and bring on the other tack, and lie-by, or 
