CRO 



CRU 



which arc of the value of five shillings 

 sterling. See COIN. 



CIIOWN, in architecture, denotes the 

 uppermost member of the cornice, called 

 also corona. 



CROWN, in astronomy, a name given 

 to two constellations, the one called bo- 

 realis, the other meridionalis. See Co- 

 BONA. 



CROWN, in geometry, is a plane ring 

 included between two concentric perime- 

 ters, and is generated by the motion of 

 some part of a right line round a centre, 

 the said moving part not being contigu- 

 ous to the centre. 



The area of a crown will be had by 

 multiplying its breadth by the length of 

 the middle periphery ; for a series of 

 terms in arithmetic progression being nX 



> that is, the sum of the first and 



lust multiplied by half the number of 

 terms, the middle element must be 



< ~^- ; wherefore that 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 co- 

 lours of the rainbow, and at a less dis- 

 tance than the common 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 according 

 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 crimi- 

 nal causes, and is thereupon 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 properly 

 the king's own suits, and filed ex officio 

 by his own immediate officer, the attor- 

 ney-general, 2. Those in which, though 

 the king is the nominal prosecutor, yet 

 it is at the relation of some private person, 

 or common informer : and these are 

 filed by the king's coroner and attornev, 



VOL. IV. 



usually called the master of the crown 

 office. 



CUOWN wheel of a -watch, the upper 

 wheel next the balance, which by its mo- 

 tion drives the balance, and in. royal pen- 

 dulums is called the swing-wheel. 



CROWN work, in fortification, an out- 

 work, having a very large gorge, gene- 

 rally the length of the curtain of the place, 

 and two long sides terminating towards 

 the field in two demi-bastions, each of 

 which is joined by a particular curtain 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. Ru- 

 biaceae, Jussieu. Essential character : 

 calyx two leaved ; 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 bract- 

 ed, in close terminating spikes, some- 

 times in corymbs. Natives of warm cli- 

 mates, 



CRUCIBLE, a chemical vessel made 

 of earth, and so tempered and baked as 

 to endure the greatest fire. See LABO- 

 RATORY. 



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 

 Decandria Monogynia class and order, 

 and found in Wildenow under this name, 

 now referred to CYCIAS, which see. 



CRUIZERS, in naval affairs, vessels, as 

 the name imports, employed on a cruize. 

 They are in truth small men of war, 

 made use of in the channel and else- 

 where, to secure our merchants' ships 

 and vessels from the enemy's small fri- 

 gates and privateers. They are generally 

 formed for sailing well, and are com- 

 monly well manned. The safety of the 

 trade in the channel requires keeping 

 out such ships at sea. 



CRUSTACEOUS animals, in natural 

 history, those covered with shells, con- 

 sisting of several pieces or scales, as 

 those of crabs, lobsters, &c. These are 

 generally softer than the shells of the 

 testaceous kind, which consist of but few 

 pieces or valves, and commonly thicker 

 and stronger than the former; such as 



