SUP 
SUPPLEMENT of an arch, in geome- 
try, or trigonometry, is the number of de- 
grees that it wants of being an intirc semi- 
circle ; as a complement, signifies what an 
arch wants of being a quadrant. 
SUPPORTED, in heraldry, a term ap- 
plied to the uppermost quarters of a shield 
when divided into several quarters, these 
seeming as it were supported or sustained 
by those below. The chief is said to be 
supported when it is of two colours, and 
the upper colour takes up two-thirds of it. 
In this case it is supported by the colour 
underneath. 
SUPPORTERS, in heraldry, figures in 
an achievement placed by the side of the 
shield, and seeming to support or hold up 
the same. Supporters are chiefly figures 
of beasts : figures of human creatures, for 
the tike purpose, are properly called te- 
nants. Some make another difference be- 
tween tenant and supporter: when the 
shield is borne by a single animal, it is called 
tenant; when by two, they are called sup- 
porters. The figures of things inanimate 
sometimes placed aside of escutcheons, but 
not touching or seeming to bear them, 
though sometimes called supporters, are 
more properly cotises. The supporters of 
the British arms are a lion and an unicorn. 
In England, none under the degree of a 
banneret are allowed supporters, which are 
restrained to those called the high nobility. 
The Germans permit none but princes and 
noblemen of rank to bear them ; but among 
the French formerly the use of them was 
more promiscuous. 
SUPPRESSION, in grammar and rhe- 
toric, denotes an omission of certain words 
in a sentence, which yet are necessary to 
full and perfect construction: as, “ I come 
from my father’s that is, “ from my fa- 
ther’s house.” Suppression is a figure of 
speech very frequent in our language, 
chiefly used for brevity and elegance. 
Some rules relating thereto are as follow ; 
1. Whenever a word comes to be repeated 
in a sentence oftener than once, it is to be 
suppressed. Thus we say, “ This is my 
master’s horsf,” not “ This horse is my 
master’s horse.” 2 . Words that are neces- 
sarily supplied may be suppressed : and, 
3. All words that use and custom suppress 
in other languages, are also to be suppressed 
in English, unless there be particular rea- 
sons for the contrary. 
Suppression is also a figure in speech 
whereby a person in rage, or other disturb- 
ance of mind, speaks not out all he means, 
SUR 
but suddenly breaks off his discourse. Thus 
the gentleman in Terence, extremely in- 
censed against his adversary, accosts him 
with this abrupt saying “ Thou of all.” 
The excess of his indignation and rage 
choaked the passage of his voice, and would 
not sufiFer him to utter the rest. But in 
these cases, though the discourse is not 
complete, the meaning is readily under- 
stood, and the evidence of the thought ea- 
sily supplies the defect of words. Sup- 
pression sometimes proceeds from modesty 
and fear of uttering any word of ill and 
offensive sound. 
SURD, in arithmetic and algebra, de- 
notes any number or quantity that is incom- 
mensurable to unity: otherwise called an 
irrational number or quantity. 
The square roots of all numbers, except 
1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144 
&c. (which are the squares of the integer 
numbers, 1 , 2 , 3, 4, 5, 6, 7, 8, 9, 10, 11 , ig, 
&c.) are incommensurables : and after the 
same manner the cube roots of all numbers 
but of the cubes of 1, 2 , 3, 4, 5, 6, &c. are 
incommensurables : and quantities that are 
to one another in the proportion of such 
numbers, must also have their square-roots, 
or cube roots, incommensurable. 
The roots, therefore, of such numbers, 
being incommensurable, are expressed by 
placing the proper radical sign over them : 
thus \/ 3, 6, 6, &c. express num- 
bers incommensurable with unity. How- 
ever, though these numbers ale incommen- 
surable themselves with unity, yet they are 
commensurable in power with it ; because 
their powers are integers, that is, multiples 
of unity. They may also be commensurable 
sometimes with one another, as the .^8 and 
' \/2 ; because they are to one another as 2 
to 1 : and when they have a common mea- 
sure, as y'2 is the common measure of 
both ; then their ratio is reduced to an ex- 
pression in the least terms, as that of com- 
mensurable quantities, by dividing them by 
their greatest common measure. This com- 
mon measure is found as in commensurable 
quantities, only the root of the common 
measure is to be made their common divi- 
sor: thus ^ = y/ 4 = 2, and — 
o ,/ a. 
A rational quantity may be reduced to 
the form of any given surd, by raising the 
quantity to the power that is denominated 
by the name of the surd, and then setting 
the radical sign over it : thus a = _ 
