P K P R 793 a stylist. Two of Prodicus s discourses were especially famous: one, "on propriety of language," is repeatedly alluded to by Plato; the other, entitled wpai, contained the celebrated apologue of the choice of Heracles, of which the Xenophontean Socrates (Mem., ii. 1, 21 sq.) gives a summary. Theramenes, Euripides, and Isocrates are said to have been pupils or hearers of Prodicus. For some personal traits, and a caricature of his teaching, see Plato s Protagoras, 315 C sq., 337 A sq. On the Sophistical movement, as well as for bibliographical information, see SOPHISTS. PROHIBITION is defined by Blackstone as "a writ directed to the judge and parties of a suit in any inferior court, commanding them to cease from the prosecution thereof, upon a surmise either that the cause originally or some collateral matter arising therein does not belong to that jurisdiction, but to the cognizance of some other court." A writ of prohibition is a prerogative writ that is to say, it does not issue as of course, but is granted only on proper grounds being shown. Before the Judica ture Acts prohibition was granted by one of the Superior Courts at Westminster ; it also issued in certain cases from the Court of Chancery. It is now granted by the High Court of Justice. Up to 1875 the High Court of Ad miralty was for the purposes of prohibition an inferior court. But now by the Judicature Act, 1873, 36 & 37 Viet. c. 66, 24, it is provided that no proceeding in the High Court of Justice or the Court of Appeal is to be restrained by prohibition, a stay of proceedings taking its place where necessary. The Admiralty Division being now one of the divisions of the High Court can therefore no longer be restrained by prohibition. The courts to which it most frequently issues in the present day are the ecclesiastical courts, and county and other local courts, such as the Lord Mayor s Court of London, the Court of Passage of the city of Liverpool, and the Court of Record of the hundred of Salford. In the case of courts of quarter sessions, the same result is generally obtained by certiorari. The extent to which the ecclesiastical courts were restrainable by prohibition led to continual disputes for centuries between the civil and ecclesiastical authorities. Attempts were made at different times to define the scope of the writ, the most conspicuous instances being the statute Gircum&pecte Agatis, 13 Edw. I. st. 4; the Articuli Cleri, 9 Edw. II. st. 1 ; and the later Articuli Cleri of 3 Jac. I., consisting of the claims asserted by Archbishop Bancroft and the reply of the judges: The law seems to be un doubted that the spiritual court acting in spiritual matters pro salute animx cannot be restrained. The difficulties arise in the application of the principle to individual cases. Prohibition lies either before or after judgment. In order that proceedings should be restrained after judgment it is necessary that want of jurisdiction in the inferior court should appear upon the face of the proceedings, that the party seeking the prohibition should have taken his objection in the inferior court, or that he was in ignorance of a material fact. A prohibition goes either for excess of jurisdiction, as if an ecclesiastical court were to try a claim by prescription to a pew, or for transgression of clear laws of procedure, as if such a court were to require two witnesses to prove a payment of tithes. It will not as a rule be awarded on a matter of practice. The remedy in such a case is appeal. Nor will it go, unless in excep tional cases, at the instance of a stranger to the suit. The procedure in prohibition is partly common law, partly statutory. By 50 Edw. III. c. 4 prohibition is not to be awarded after consultation, i.e., after the judges of the superior court have remitted the case as within the juris diction of the inferior court. 1 Will. IV. c. 21 (an Act to improve the proceedings in prohibition and on writs oi mandamus) was repealed as to England by 46 & 47 Viet. . 49, but it still applies to Ireland, to which it was xtended by 9 & 10 Viet. c. 113. Application for a pro- libition is usually made ex parte to a judge in chambers m affidavit. The application may be granted or refused, [f granted, a rule to show cause why a writ of prohibition hould not issue goes to the inferior judge and the other
- )arty. In prohibition to courts other than county courts
pleadings in prohibition may be ordered. These pleadings are as far as possible assimilated to pleadings in actions. They are rare in practice, and are only ordered in cases of great difficulty and importance. In prohibition to county ourts they cannot be ordered, 19 & 20 Viet. c. 108, 42. Further statutory regulations as to prohibition to county courts are contained in 40, 41, and 44 of the same Act, and in 13 & 14 Viet. c. 61, 22. Much learning on the subject of prohibition will be found in the opinion of Mr Justice Wills delivered to the House of Lords in The Mayor and Aldermen of London v. Cox (Laiv Rej)orts, 2 Eng. and Ir. Appeals, 239). In Scotch law prohibition is not used in the English sense. The same result is obtained by suspension or reduction. In the United States the supreme court has power to issue a prohibition to the district courts when proceeding as courts of admiralty and maritime jurisdiction. Most of the States have also their own law upon the subject, generally giving power to the supreme judicial authority in the State to prohibit courts of inferior jurisdiction. PROJECTILES. See MECHANICS (vol. xv. pp. 682 sq., 706 sq.) and GUNNERY. PROJECTION. If from a fixed point S in space lines or rays be drawn to different points A,B,C, . . . in space, and if these rays are cut by a plane in points A ,B ,C , . . . the latter are called the projections of the given points on the plane. Instead of the plane another surface may be taken, and then the points are projected to that surface instead of to a plane. In this manner any figure, plane or in space of three dimensions, may be projected to any surface from any point which is called the centre of pro jection. If the figure projected is in three dimensions then this projection is the same as that used in what is generally known as perspective. In modern mathematics the word projection is often taken with a slightly different meaning, supposing that plane figures are projected into plane figures, but three- dimensional ones into three-dimensional figures. Projec tion in this sense, when treated by coordinate geometry, leads in its algebraical aspect to the theory of linear substi tution and hence to the theory of invariants and co-variants. In this article projection will be treated from a purely geometrical point of view. We shall first and principally treat of the projection of plane figures into plane figures, and consider a number of special cases due to special positions of the two planes or of the centre of projection. We shall next consider the representation of figures of three dimensions by plane figures (orthographic projections, drawing in plan and elevation, &c.), then treat of perspective in its ordinary sense, and speak shortly of projections to curved surfaces. References like (G. 87) relate to section II. of the article GEOMETRY, vol. x. pp. 388 sq. 1. PROJECTION OF TLAXE FIGURES. Let us suppose ve have in space two planes ir and IT . In the plane IT a figure is given having known properties ; then we have the problem to find its projection from some centre S to the plan* ir , and to deduce from the known properties of the given figure the properties of the new one. If a point A is given in the plane ir we have to join it to the centre S and find the point A where this ray SA cuts the plane TT ; it is the projection of A. On the other hand if A is given in the plane IT , then A will be its projection in v. Hence if one figure in ir is the projection of another in ir, then conversely the latter is also the projection of the former. A point and its projection are therefore also called corresponding points and similarly we speak of corresponding lines and curves, &c.
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