733 



CENTRE. 



CENTRE. 



734 



the court is authorised to try offences committed on the high seas and 

 other places within the jurisdiction of the Admiralty of England, and 

 by the 19 k 20 Vic. c. 16, the court of Queen's Bench may order 

 certain offenders to be tried at this court. The justices of the peace 

 were prohibited by the Act from trying at their sessions persons 

 charged with capital and a variety of other offences, alleged to have 

 been committed within the jurisdiction of the Act ; but the restriction 

 was repealed by the 14 & 15 Vic. c. 55. This jurisdiction comprises 

 the whole of Middlesex ; in Essex, the parishes of Barking, East Ham, 

 West Ham, Little Ilford, Low Layton, Walthamstow, Waustead, 

 Woodford, and Chingford ; in Kent, Charlton, Lee, Lewisham, 

 Greenwich, Woolwich, Eltham, Plumstead, St. Nicholas's Deptford, 

 that part of St. Paul's Deptford which is within Kent, the liberty of 

 Kidbrook, and the hamlet of Nottingham ; in Surrey, the borough of 

 Southwark, the parishes of Battersea, Bermondsey, Camberwell, Christ- 

 church, Clapham, Lambeth, St. Mary Newington, llotherhithe, Streat- 

 ham, Barnes, Putney, that part of St Paul's Deptford which is within 

 Surrey, Tooting, Graveney, Wandsworth, Merton, Mortlake, Kew, 

 Richmond, Wimbledon, the Clink Liberty, and the district of Lambeth 



For all purposes under the Act the above district is considered as one 

 county, an<f in all indictments and presentments the venue runs 

 " Central Criminal Court, to wit." 



The judges of the Central Criminal Court are appointed by the Act 

 to be any two or more of the following persons ; the lord mayor for 

 the time being of the city of London, the lord chancellor or the lord 

 keeper of the great seal, and all the judges for the time being of his 

 Majesty's courts of King's Bench, Common Pleas, and the Exchequer, 

 the chief judge and the two other judges in Bankruptcy, the judge of 

 the Admiralty, the dean of the arches, the aldermen of the city of 

 London, the recorder, the common Serjeant, the judges of the sheriff's 

 court of the city of London for the time being, and any person or 

 persons who hath or shall have been lord chancellor, lord keeper, or a 

 judge of any of hia majesty's superior courts of Westminster, together 

 with such others as his Majesty, his heirs and successors, shall from 

 time to time name and appoint by any general commission. The power 

 of selecting the judges from so extensive a list renders it unnecessary 

 to issue a commission eve^y time the sessions are held, and the period 

 of holding the sessions is not interrupted when the judges of the courts 

 at Westminster are absent on circuit. The sessions are held twelve 

 times a-year at the Old Bailey and in the New Court adjoining, and 

 the judges are usually two of the common-law judges and the recorder 

 of the city of London. Before the Central Criminal Court was esta- 

 blished, sessions were held at the Old Bailey eight times a-year for the 

 trial of offences committed in Middlesex, and bills were returned by a 

 grand jury sitting at Clerkenwell under the jurisdiction of the county 

 magistrates. Offences committed at Southwark or Greenwich, both of 

 which places may be regarded as parts of the metropolis, were, in the 

 case of Southwark, tried at Guildford, Kingston, or Croydon, as it 

 might happen, and from Greenwich an offender was sent for trial to 

 Maidstone. From the great amount of population, the calendars were 

 necessarily so heavy that a winter assize became necessary for parts of 

 the Home Circuit ; but it was still better to place the whole metro- 

 ]K>litin district under one jurisdiction, and to have a gaol delivery every 

 four or five weeks. 



Jurors are summoned by the sheriffs of the city of London and of 

 the counties of Middlesex, Essex, Kent, and Surrey, according to the 

 parts of the district in which they reside. The juries are selected from 

 London alone ; or from Middlesex, and the parts of counties which are 

 within the limits of the act ; or from both indiscriminately. Jurors 

 from Essex, Kent, and Surrey, who have served upon any jury at the 

 ( ,'ntral Criminal Court are exempted, for the ensuing twelve months, 

 from serving upon any jury in any court (except the sessions of the 

 peace) held in the county in which they reside. 



By the Stat. 7 Will. IV. and 1 Viet. o. 77, the practice of this court 

 was assimilated to other courts of criminal judicature with respect to 

 offenders liable to the punishment of death ; and by the.9 & 10 Viet. 

 c. 24, indictments may be preferred before the grand jury of the Central 

 Criminal Court in the same manner as before any other grand jury. 



The area over which the jurisdiction of the Central Criminal Court 

 extends is about the 130th. part of the area of England and Wales, but 

 the population is between one-seventh and one-eighth of that of 

 England and Wales. Nearly as many prisoners are annually tried at 

 the Central Criminal Court as at all the county assize courts in 

 England and Wales. 



CENTRE, from the Greek Ktvrpov, a sharp point. This word, by 

 its successive introduction in one sense and another, has become a 

 generic term for any point of a figure or solid body, such that the 

 whole of the figure or body might be collected into that point, without 

 any alteration except in some respect or other which is specified. It 

 in, in fact, an average point, as the following species of it will show : 



1. Centre of Cavity. [MOTACENTRE.] 



2. Cm/re of a Curve. The point where any two diameters of the 

 curve Intersect one another. When all the diameters intersect at this 

 point, Newton calls it the general centre. 



3. C'mtrr of a Died is the point where the gnomon or style, which is 

 gwrally parallel to the alia of the earth, intersect* the plane of 

 the dial. 



4. Centre of Figure. If any number of points be situated in given 

 positions with respect to a plane (A), their average perpendicular dis- 

 tance from the plane is common to all the points of a second plane (B), 

 parallel to (A). If two other planes (A') and (A") be taken, and 

 if (B') and (B") be planes distant from them by the average distances 

 of the points, then (B), (B'), and (B") will meet in a point which is 

 obviously distant from the three planes by the several average dis- 

 tances of the points. And it is proved, by the application of algebra, 

 that the point thus determined is also distant from any other plane 

 whatsoever by the average distance of the points ; whence it may be 

 called the centre of figure of the points. It is usual to call it the 

 centre of gravity, which it is on one particular supposition only, 

 namely, that the points are supposed to have equal weights. 



A solid figure cannot be supposed to be made up of points ; but if 

 it be divided into a number of equal elementary portions, and if one 

 point be taken in each, and the centre of figure then found in the 

 manner just described, the principles and processes of the integral 

 calculus will determine the centre of figure of the portion of space 

 within the limits of the whole solid. This, as before, is only the 

 centre of gravity, on the supposition that the solid is of Uniform 

 density throughout. 



The centre of gravity may be made useful in finding the contents of 

 surfaces and solids formed by revolution, as follows : 



i. If an arc revolve round an axis the surface traced out is equal to 

 a rectangle, one side of which is equal in length to the arc, and the 

 other to the arc of a circle through which the centre of gravity of the 

 revolving arc passes. 



ii. If an area revolve round an axis, the volume of the solid thus 

 generated is equal to a cylinder or prism which has the area for its 

 base, and the arc traced out by the centre of gravity of the area for 

 its altitude. 



These propositions are the foundation of what has been called the 

 centro-baryc method. 



5. Centre of Force or A ttraclion. That point to which all the parts 

 of a system are attracted by virtue of the force emanating from it, or 

 inherent in it. 



6. Centre of Friction. This is a term now fallen into comparative 

 disuse. It is that point in the base of a body on which it revolves, 

 into which, if the whole surface of the base and mass of the body 

 were collected, and made to revolve about the centre of the base, .the 

 angular velocity destroyed by friction would equal the angular velocity 

 destroyed in the body by its friction in the same time. 



7. Centre of Gratify. This is the point at which the weight of the 

 body being collected, the equilibrium of the body and of the system 

 (if any), of which it forms a part, will not be disturbed. 



8. Centre of Gyration. This term, which is almost peciiar to 

 English mathematicians, has the following meaning : it is the point at 

 which, if the whole of the matter in a body were collected, given 

 forces would produce the same angular velocity of rotation in a given 

 time as they would do if the particles of the body were distributed in 

 their proper places. This centre is of course dependent upon the axis 

 of rotation as well as the form, &c. of the body ; every axis which can 

 be chosen has its own centre of gyration. 



9. Centre of a Lens. When the surfaces of a lens are concentric, 

 the centre is, of course, equidistant from each of them ; but when 

 they are of different curvatures, the centre of the lens is nearer to one 

 vertex than to the other, by as much as the radius of curvature of the 

 former is less than that of the latter. 



10. Centre of Oscillation. The point in which the whole of the 

 matter must be collected, in order that the time of oscillation may be 

 the same as when it is distributed. 



11. Centre of Percussion. That point of a revolving body which 

 would strike an obstacle with the same force as if the whole of the 

 matter were collected in it. 



12. Centre of Pressure. The point at which the whole amount of 

 pressure may be applied with the same effect as it has when dis- 

 tributed. 



13. Centre of Suspension of a pendulum or other vibrating body 

 having an angular velocity round a fixed axis, is convertible with the 

 centre of oscillation, and hence is the point by which the body 

 must be suspended in order to vibrate in the same time as if suspended 

 by its centre of oscillation. 



14. Centre of Symmetry. That point in a figure or body round 

 which the parts of it are similarly disposed, or have the same shape, 

 size, Ac., on each side. For methods of finding these several centres, 

 see GRAVITY, &c., CENTRES OF. 



In old writers, from the earliest periods, the term centre is used in 

 the sense of a supposed centre of the universe, which it was imagined 

 must coincide with the geometrical centre of the earth. And it was 

 supposed to be a most obvious principle that all bodies must fall to 

 this centre, which being a notion derived from the observation that 

 all bodies fall towards the centre of the earth, was made an argument 

 in favour of the stability of the latter. Even Copernicus has a notion 

 of the existence of such a centre, or medium mundi, which, however, 

 he places in the sun, while others consider one of the Pleiades to be 

 the point in question. It is hardly necessary now to say that there is 

 no evidence whatever for the existence of any centre of the universe, 

 that is, of any point which must necessarily remain fixed ; but so well 



