cm 
Circles nf position, are circles passing 
Hiroiisli the common intersections of the 
horizon and meridian, and through any de- 
gree of the ecliptic, or the centre of any 
star, or other point in the heavens; and are 
used for finding out the situation or position 
of any star. 
Circles, Druidical, a name given to 
certain ancient inclosures, formed by rude 
stones circularly arranged. These, it is 
supposed, were temples, or places for solemn 
assemblies for councils, or seats of judgment. 
These temples, though generally circular, 
occasionally differ in magnitude. The most 
simple were composed of one circle. Stone- 
henge consisted of two circles and two ovals, 
respectively concentric. One near St. Just, 
in Cornwall, is formed of four intersecting 
circles. In magnitude these differ very 
much : some are formed of only 12 stones, 
while others, as Stonhenge and Abury, con- 
tained, the first 140, and the second 652, 
and occupied many acres of ground. These 
different numbers, measures, and arrange- 
ments are supposed to have had reference, 
either to the astronomical divisions of the 
year, or some mysteries of the Druidical re- 
ligion. 
CIRCUIT, in electricity, denotes the 
course of the electrical fluid from the charged 
surface of an electric body to the opposite 
surface on which the discharge is made. 
Circuit, in law, signifies a longer course 
of proceedings than is needful to recover the 
thing sued for ; in case a person grants a rent- 
charge of 101. a year out of his manor, and af- 
terwards tlie grantee disseises tlie grantor, 
who thereupon brings an assise, and recovers 
the land, and 201. damages ; which being paid, 
the grantee brings his action for 101. of the 
rent, due during tlie time of the disseism ; this 
is termed circuity of action, because as the 
grantor was to receive 201. damages, and 
pay 101. rent, he might only have received 
the 101. for the damages, and the grantee 
might have retained the other 101. for 
his rent, and by that means saved his 
action. 
Circuit also signifies the journey, or pro- 
gress, which the judges take twice every 
year, through the several counties of Eng- 
land and Wales, to hold courts and admi- 
nister justice, where recourse cannot be 
had to the King’s courts at Westminster; 
hence England is divided into six circuits, 
uiz. The home circuit, Norfolk circuit. Mid- 
land circuit, Oxford circuit. Western circuit, 
and Northern circuit. In Wales tliere are 
but two circuits, North and South Wales. 
CIR 
Two judges are assigned by the King’s com 
mission to every circuit. In Scotland there 
are three circuits, riz. the Southern, Western, 
and Northeni, which are likewise made 
twice every year, viz. in spring and au- 
tumn. 
CIRCULAR lines, in mathematics, such 
straight lines as are divided from the divi- 
sions made in the arch of the limb, such as 
sines, tangents, secants, chords, &c. 
Circular numbers, called also spherical 
ones, according to some are such whose 
powers terminate in the roots Uiemselves. 
Thus, for instance, 6 and 6, all whose 
powers do end in 5 and 6, as the square of 
6 is 25, tlie square of 6 is 36, &c. 
CIRCULATION of the blood, the natu- 
ral motion of the blood in a living animal, 
whereby that fluid is alternately carried 
from the heart to all parts of the body by 
the arteries, and returned from the sara$ 
parts to the heart by the veins. See Phy- 
siology. 
CIRCUMFERENCE, in a general sense, 
denotes the line or lines bounding a plane 
figure. However, it is generally used in a 
more limited sense, for the cm ve line wiiich 
bounds a circle, and otherwise called a 
periphery ; the boundary of a right-lined 
figure being expressed by the term peri- 
meter. 
The circumference of every circle is sup- 
posed to be divided into 360 degrees. The 
angle at the circumference of a circle js 
double that at the centre. For the ratio of 
tlie circumference of a circle to its radius, 
see Circle. 
CIRCUMFERENTOR, a mathematical 
instrument used by land-surveyors for tak- 
ing angles by the magnetic needle. It is an 
instrument (where great accuracy is not 
desired) much used in surveying, in and 
about woodlands, commons, harbours, sea- 
coasts, in the working of coal-mines, 6cc. &c. 
where a permanent direction of the needle 
is of the most material consequence in sur- 
veying. The instrument is made of brass, 
and, in its most simple state, consists of the 
following parts : a brass compass box; about 
five inches diameter, or more ; on the plate 
of the box are engraved and lettered the 
principal points of the compass, divided 
into four quarters of 90 degrees each, two 
of the quarters being figured from the south 
point, and terminated by 90 degrees at the 
east and west; and the otlier two quarters 
from the north point, terminating also at 
the east and west: on the circumference of 
the plate is fixed a ring, divided into 360 
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