COMPOST. 240 COMPRESSED-AIR LOCOMOTIVE. vantage. Composts are not so well suited to the forcing of quifk-growing crojis as toiiimereial fertilizers. For specific directions for preparing dift'erenl kinds of i-omposts, consult : Dana, Muck Mainitil for fiiniifrs (4th ed.. New York, ISoS) ; Storcr, Ayricull ure in ISomc of its lie- J(itio)if: mill Chemistry (7th ed., New York, 1897) ; .Johnson, Peril and its Uses as Fertilizer <ind Fuel (New York. 1800) : Sempers. Manures: How to Make and How to Use Them (Philadel- phia. 1S03). COM POSTEL'LA, Order of Saint J.mes OF, or Order of Saint James of the .Sword. An order of knighthood in Spain. To defend the multitude of pilgrims that thronged to the shrine of Saint James at Compostella (Santiago), in Galicia, Spain, from the Moors, thirteen noble- men formed themselves into a military Order, under the ausjjices of the Pope, in 1175. With time the Order rose to immense power and wealth. It fought valorously in all the Moorish wars, and exercised great political influence. But its rich towns and abbeys tempted Ferdi- nand and Isabella, who took possession of its ]jroperty in 1403 and held it until 1.522, when a Papal bull vested the jjermanent grand-master- ship in the Crown. COMPOTJND, t'lmiicAL. See Chemistry. COMPOUND ANIMALS. Such animals as are made up of a number of morphological units, called persons, which are organically connected throughout life. The connection results from a budding process, in which the l)uds never become separated from the parent stock. Compoimd animals are found among protozoans, sponges, coelenterates, certain flatworms (planarians and tapeworms), bryozoans. .some annelids (Syllis), and timicates. The degree of connection varies. When it is loose the complex is called a stock ; when close a corm, as in sponges. !Most com- pound animals are sessile, but the siplionophores, Hatworms. and some tunicates swim free. The opposite of this tenn is 'simple animals.' COMPOTJND DUPLE TIME. See Time. COMPOUND FRACTURE. A fracture of a bone accompanied by a wound which opens from the surface of the body to the break in the bone. Infection of the bone being thus rendered possible, a compovuid fracture is more serious tlian a simple fracture. See Fracture. COMPOUNDING OF FELONY. The offense of taking value for forbearing to prosecute a felony. This offense is punishable with fine and imprisonment. Compounding of informations upon penal statutes, and compounding of mis- demeanors, are also illegal, and are punishable in a lighter degree. In Great Britain Die com- pounding of misdemeanors is permitted in some cases with the leave of the court, especially in the case of a misdemeanor affecting private (and not public) rights. Accepting a promissory note signed by a party guilty of larceny, as a consider- ation for not prosecuting, is enough to constitute the offense; but the mere retaking of stolen goods by the owner is not an offense, unless it is agreed that the thief is not to be prosecuted. A note or other obligation given in consideration of stopping a criminal prosecution or an agree- ment not to prosecute is void. See Crimin.l Law, and consult the authorities referred to there. COMPOUND INTEREST. See Interest. COMPOUND MICROSCOPE. See .Micro- scope. COMPOUND TRIPLE TIME. See Time. COMPRADOR' (Sp., I'ort., purchaser). In China, Japan, and the Philippines, a man who contracts for the sujjply of provisions to ships. COMPRESSED AIR. See Power Trans- mission ; Air Compressor: Compressed- Air Engine; Compressed-Air Locomotive; Pneu- matic Tools; Pneum.^tic Dispatch. COMPRESSED-AIR ENGINE. An engine using as a mutur lluid air to which a degree of energy lias been imparted by compression by mechanical means. Vhen atmospheric air is compressed in an air compressor (see Air Com- pressor) energy is stored in it which is avail- able for work in a piston motor just as in the energy stored i;i steam. Any form of engine which will ojierate with steam as a motive fluid will also operate with compressed air as a motor fluid, that is. a steam-engine will become a com- pressed-air engine simply by disconnecting the steam boiler and substituting a receiver or reservoir of compressed air. Compressed air is, however, employed to replace steam only under those conditions in which it is necessary to transmit the motor fluid to motors located at scattered points some distances from the source of supply. The reason for this is that while it is not possible to convey steam through pipes or to carry it in inclosed vessels for long dis- tances without a great loss of energy due to condensation, it is practicable to do this with compressed air. with a comparatively small loss of energy if the air be heated Ijefore it is de- livered to the motors at the end of its journey.' Hence, compressed-air engines are practically always motors of sjiecial tonus for performing special operations, and are usually of small size. For descriptions of the various special forms of compressed - air engines in common use, see Drills ; Pneumatic Tools ; Power Transmis- sion; Street Bailways. COMPRESSED - AIR LOCOMOTIVE. A locomotive engine in which air luider pressure takes the place of steam as the propulsive force. Compressed-air locomotives occupy a rather limit- ed field of usefulness at present, their chief ap- ])lications being street-railway propulsion on a limited scale, mine, quarry, and tunnel haulage and haulage around cane plantations, saw-mills, cotton-presses and warehouses, textile-works, and powder-mills, where the risk of fire has to be carefully avoided. Structurally, a com- ])ressed-air locomotive has the same form of pro- pelling mechanism as a steam locomotive, but in place of the boiler there are tanks for holding compressed air, these tanks being recharged at intervals at a stationary air-compressor plant. A brief description of the use of compressed-air locomotives for street-railway propulsion and for mine haulage will give a fair idea of the two distinctive classes of these motors. Street-Railway Locomotives. Niimerous at- tenqits have been made, in the United States, to employ compressed-air locomotives for projiel- ling street-railway cars; but. with the exception of a few short lines operating under special con- ditions, these att^-mpts have all resulted in com- mercial failures. Probablv the most extensive
