CRO 
CRU 
Crown, in architecture, denotes the up* 
permost member of the cornice, called also 
corona. 
Crown, in astronomy, a name, given to 
two constellations, the one called borealis, 
the other meridionalis. See Corona. 
Crown, in geometry, is a plain ring in- 
cluded between two concentric perimeters, 
and is generated by the motion of some 
part of a right line round a centre, the said 
moving part not being contiguous to tlie 
centre. 
The area of a crown will be had by mul- 
tiplying its breadth by the length of the 
middle periphery ; for a series of terms in 
arithmetic progression being n X 
that is, the sum of the first and last multi- 
plied by half the number of terms, the mid- 
dle element must be wherefore that 
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Crown work, in fortification, an outwork 
having a very large gorge, generally the 
length of the curtin of the place, and two 
long sides terminating towards the field 
in two demi-bastions, each of which is joined 
by a particular curtin to a whole bastion, 
which is the head of the work. The crown- 
work is intended to inclose a rising ground, 
or to cover the head of a retrenchment. 
CRUCIANELLA, in botany, a genus of 
the Tetrandria Monogynia class and order. 
Natural order of Stellatae. Rubiaceae, Jus- 
sieu. Essential character : calyx two-leav- 
ed ; corolla one-petalled, funnel-form, with 
a filiform tube and tailed border; seeds 
two, linear. There are nine species. These 
are herbaceous plants ; leaves stellate, from 
four to six in a whorl, often linear; flowers 
bracted, in close terminating spikes, some- 
times in corymbs. Natives of warm cli- 
mates. 
•multiplied by the breadth, or sum of all the 
two terms, will give the crown. 
Crown of colours, certain coloured rings 
which, like halos, appear about the body of 
the sun or moon, but of the colours of tlie 
rainbow, and at a less distance than the com- 
mon halos. These crowns Sir Isaac Newton 
shews to be made by the sun’s shining in a 
fair day, or the moon in a clear night, 
through a thin cloud of globules of water or 
hail, all of the same bigness. And accord- 
ing as the globules are bigger or lesser, the 
diameter of these crowns will be larger or 
smaller ; and the more equal these globules 
are to one another, the more crowns of 
colours will appear, and the colours will be 
the more lively. 
Crown office. The court of king’s bench 
is divided into the plea side and the crown 
side. In the plea side it takes cognizance 
of civil causes, in the crown side it takes 
cognizance of criminal causes, and is there- 
upon called the crown office. In the crown 
office are exhibited informations in the 
name of the king, of which there are two 
kinds: 1. Those which are truly and pro- 
perly the king’s own suits, and filed ex-offido 
by his own immediate officer, the attorney- 
general. 2. Those in which, though the 
king is the nominal prosecutor, yet it is at 
the relation of some private person or com- 
mon informer : and these are filed by the 
king’s coroner and attorney, usually called 
the master of the crown office. 
Grown wheel of a watch, the upper wheel 
next the balance, which by its motion drives 
the balance, and in royal pendulums is call- 
ed the swing-wheel. 
CRUCIBLE, a chemical vessel made of 
earth, and so tempered and baked as to en- 
dure the greatest fire. See Laboratory. 
CRUCIFORM, in botany, a term ap- 
plied to cross-shaped flowers, or flowers 
consisting of four petals, which spread at 
the top in form of a cross. Of this kind is 
the stock-gillyflower, &c. 
CRUDIA, in botany, a genus of the De- 
candria Monogynia class and order. Calyx 
one-leafed, with a two-cleft border; no 
corolla ; filaments dilated at the base ; cap- 
sule orbicular; about two-seeded. Two 
species, viz. the spicata and aromatica, 
found in Guiana. 
CRUIZERS, in naval affairs, vessels, as 
the name imparts, employed on a cniize. 
They are, in truth, small men of war made 
use of in the channel and elsewhere, to 
secure our merchant’s ships and vessels 
from the enemy’s small frigates and priva- 
teers. They are genei-ally formed for sail- 
ing well, and are commonly well manned. 
The safety of the trade in tlie channel re- 
quires keeping out such ships at sea. 
CRUSTACEOUS^sA, in natural history, 
those covered with shells, consisting of se- 
veral pieces or scales, as those of crabs, 
lobsters, &c. These are generally softer 
than the shells of the testaceous kind, which 
consist of a single piece, and commonly 
thicker and stronger than the former; such 
as those of the oyster, scallop, cockle. See 
Cancer. 
CRUSTS, in chemistry. By crusts we 
understand those bony coverings of which the 
whole external surface of crabs, lobsters, and 
other similar sea animals are composed. 
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