THE ENCYCLOPEDIA P rojectiles (from Lat. projectare, entirely superseded by stones which continued in use, to a greater or lesser extent, during several succeeding centuries, although cast-iron to thrust forward; Fr. projecter, to project). In its broadest sense, the term is applicable to all objects thrown forward for any purpose whatsoever, by a quick impulse. Specifically, it refers to the missiles thrown from the larger forins of ordnance; the term bullet being more applicable to those fired from the various forms of small-arms such as muskets, magazine rifles and pistols, revolvers, etc. (See SMALL-ARMS.) The earliest projectiles used as weapons in warfare a b e Shrapnel. Muzzle-loading Shell (Studded Shell). g Combination Time and Percussion Fuse (a) Shearing wire. (b) Hammer. (c) Steel needle. (d) Detonating cap. (e) Shearing wire. (f) Brass ball. (g) Centrifugal bolt. (h) Powder composition. (i) Copper detonator. (k) Powder. were the arrows, darts, and stones, discharged by the various forms of medieval ordnance such as the ballista and the catapult. (See ORDNANCE.) In the 14th century, when gun-powder cannon came into use, the arrows and darts were Vol. 13-1 projectiles were introduced for general use in the various European countries about the middle of the 15th century. The better shape of the iron projectiles increased the accuracy of gunfire, while the reduction of the "windage" also added considerably to their velocity. (See ORDNANCE.) Although many attempts were made to perfect a breech-loading type of cannon, which would have allowed the use of still closer-fitting projectiles, they were practically unsuccessful. Similar conditions attended the attempts to perfect rifled guns, so that the use of smooth-bored guns and spherical projectiles prevailed up to the middle of the 19th century. PROJECTILES All smooth-bored ordnance were muzzle-loaders. They fired solid round-shot, case, common shell, and shrapnel shell. Solid round-shot were made of cast iron and were used against the masonry of fortifications, wooden shipping, and massed troops. In naval battles they were often fired red-hot, being heated in special ovens before insertion in the gun. Case-shot consisted of a number of small iron or lead balls packed in metallic cylinders. At first, they were used in a form called "grape," and consisted of a number of balls arranged around a central rod with a disk fastened at each end which together with a series of rings around the several layers of balls, held them in place. The whole was covered by a canvas bag. When fired, the balls were broken loose in the bore of the gun by the shock of discharge, but were held together in the bag for some little distance before final dispersion. Grape was superseded by "canister," invented by Gen. Gribeauval of the French army, in which the thin metallic can containing the balls broke up after leaving the barrel, thus imparting to the smaller shot, at the moment of dispersion, the velocity of the projectile as a unit. Common shell were first made of two hollow hemispheres fastened together and the interior completely filled with gun-powder. They were burst in flight by time fuses. At first, the fuse had to be lighted before inserting the shell in the gun, and resulted in many dangerous premature explosions, but in 1747, the French discovered that, if the earth tamping around the shell were omitted, the fuse would be ignited by the discharge. This not only removed the great danger of shell-fire, but expedited loading, and increased its use. Shrapnel, perfected by Gen. Shrapnel of the British army, were designed for smooth-bored ordnance, but their use has been extended to rifled guns. They were used by the British with great effect during the Peninsular war, especially at the capture of Saint Sebastian, 31 Aug. 1813, when the ramparts were cleared by shrapnel-fire over the heads of the British storming end, just powerful enough to burst the cylinder and disperse the balls. They are burst by time fuses, or by percussion fuses. In the former,. the shock of discharge causes a small plunger to shear a retaining pin and explode a cap which ignites a time train at such a point that it will explode the bursting charge after a predetermined number of seconds. Usually, the calculated time allows the shell to get within 100 yards of the object, when the balls are released by the bursting charge and continue onward in the form of a shower with the velocity of the projectile before bursting. In the percussion fuse, the shock of discharge causes a small plunger to break loose from its retaining wire. When the shell strikes, the plunger is thrown forward against a cap which it explodes, and thus ignites the bursting charge in the shell. Until the earlier part of the 19th century, explosive shell had been fired from mortars and howitzers only, but in 1821, Gen. Paixhans of the French army strongly advocated their use in long guns. His shell guns, the "Paixhans," were adopted in the French navy about 1824, and led to the creation of armor-clad ships which in turn compelled the development of the rifled gun. (See ORDNANCE.) At first, the difficulty of constructing gas-tight breech-mechanisms caused the development of muzzle-loading rifles, but this erroneous system of construction did not last longer than a period of 25 years at the most, and the breech-loading rifle established itself firmly about 1875-80. Rifling.- Rifling was applied to guns to in PROJECTILES crease the accuracy of aim, and to give greater powers of penetration to the projectiles by increasing their velocity without lessening their weight. In the muzzle-loading smooth-bores the "windage" not only impaired the accuracy, but, by allowing the powder gas to rush past the projectile, reduced the velocity of its delivery; the windage completely, finally led to the removal of the studs and ribs altogether. About this time the construction of breech-loading rifles had reached such a stage of progress that considerations relative to projectiles were directed into an entirely different channel. In breechloaders the projectiles are thrust into the gun from behind, therefore they could be used slightly larger than the bore, provided the excess was made of some softer metal that could be forced into the rifling grooves. At first these projectiles were coated with lead but proved quite unsatisfactory. Subsequently they were fitted with copper bands around the base, which, being slightly larger than the bore, were forced into the grooves as the projectile was pushed forward by the pressure, and not only took up the rotation imparted by the rifling, but also acted as an effectual gas check. Modern Projectiles.- The projectiles used in modern guns are common shell, armor-piercing shell, shrapnel, and canister. Excepting the armor-piercing shell, all of them are practically the same as those already described under corresponding names. The first armor-piercing shell were designed by Sir W. Palliser, of England, and were made of chilled iron, or steel, with ogival shaped heads, a form combining strength and sharpness. They were filled with powder introduced through a hole in the base, which was subsequently closed by a strong screwplug. They were fitted with percussion fuses, arranged to explode them the instant after impact. Modern armor-piercing projectiles are used capped or uncapped. The latest forms of common shell are made with hardened points, and are designed to carry bursting charges Muzzle-loading Shell (Ribbed Shell). Modern Armor-piercing Shell (capped). while an increase in the weight of the projectile could have been obtained only by an increase of calibre with a consequent loss of power. (See ORDNANCE.) In the muzzle-loading rifle, the rotation imparted to the projectile completely eliminated the inaccuracy of aim due to windage, and by allowing the use of elongated projectiles, enabled an increase in their weight without an increase of calibre, so that the longer and relatively narrower powder chambers concentrated the gas pressure and gave greater velocities. Muzzle-loading projectiles, however, had to be pushed into the gun from the front and were necessarily smaller than the bore, consequently, they still allowed an escape of gas and prevented the maximum effect of pressure. The earlier forms were provided with ribs or studs which fitted into the rifling grooves, but as the guns increased in size, the great strain of imparting rotation at the instant of starting forced out the studs and wore away the driving edges of the grooves. These difficulties were overcome by substituting the system of "increasing twist" rifling for that of the "uniform twist," but did not obviate the shortcomings due to windage. The use of a flanged copper disk attached to the base of the projectile, which expanded under the pressure of the gas and cut off Direct Acting Percussion Fuse-(a) Safety fuse. (b) Steel needles and disk. (c) Detonating composition. (d) Powder. (e) Bottom plug. equal to five per cent of their own weight, and penetrate armor at least one half of a calibre in thickness; they are used without caps. Armor-piercing shell are made of chrome steel, forged and tempered, and are designed to penetrate any thickness of iron or steel armor, through which they may be driven, without being broken to fragments or deformed by the impact. They are fitted with percussion fuses which are actuated by the impact and explode the shell after penetration. Those exceeding six inches in calibre are not loaded, as their walls are too strong to be burst by charges of ordinary gunpowder. Various kinds of high explosives, such as gun-cotton, nitro-glycerine, and certain picric PROLAPSUS ANI-PROLOGUE acid compounds, much stronger than any from of gun-powder, have been used as bursting charges with more or less success, but the ever present danger from premature explosions due to the shock of discharge, has probably prevented the general adoption of any of them. (See EXPLOSIVES.) The thickness of homogeneous iron or steel armor they were capable of penetrating was limited only to their striking velocity, but against face-hardened armor they broke into fragments, or were flattened out and welded to the plates. It was discovered that the old compound armor could be easily pierced by them from the soft side. This led to the experiment of fitting soft-steel caps over their points, which were found to add greatly to their powers of penetration. Armor-piercing shell are generally about three and a half calibres in length, and weigh about one half of the cube of Hale Rocket. the calibre (expressed in pounds). (See NAVAL GUNS.) The projectiles used in pneumatic guns form a class by themselves. They are best represented by those discharged by the Zalinski, Sims-Dudley, and the Gathmann guns. They were designed to carry large quantities of guncotton, nitro-glycerine, or other high explosives. Each Gathmann shell contained at least one quarter of a ton of wet gun-cotton, and under test showed great destructive powers at a range of 5,000 yards. (See ORDNANCE.) Rockets form still another class of projectiles and are of three kinds war rockets, signal rockets, and lifesaving rockets. A rocket consists of a pasteboard or a metallic cylinder containing an inflammable composition which, when ignited, generates a quantity of gas of sufficient power to propel it forward. War rockets appear to have been first used in Oriental countries, and probably were invented by the Chinese. They were introduced in the British service by Sir W. Congreve, about 1827, who made them of iron cylinders, and used them for incendiary purposes. Congreve rockets were kept point-first, as they were driven through the air, by sticks fastened to their bases parallel to the axis of the cylinder, and worked on the principle of the feathers of an arrow. They were superseded by the Hale rocket which is kept point-first by the axial rotation imparted to the cylinder by a threecurved shield attached to its base, and actuated by the pressure of the gas escaping from the vents. Signal or sky rockets are small pasteboard cylinders with cone-shaped heads, filled with the composition which generates the propelling gas; a small bursting-charge of powder; and a quantity of other ingredients which, when the rocket bursts at its highest point of elevation, ignite into colored stars of great brilliancy, and visible at a great distance. Life-saving rockets are employed to carry a line over a wreck and thus establish communication between the vessel and the shore. Bibliography.-Special information on projectiles may be obtained from: Cooke, 'Text Book on Ordnance and Gunnery); Bruff, 'Ordnance and Gunnery); Ingersoll, Text Book on Ordnance and Gunnery); Journal of the United States Artillery); Proceedings of the United States Naval Institute'; Text Book on Ammunition (British War Office).' W. MOREY, JR., Consulting Civil Engineer. Prolapsus Ani, falling of the anus. See RECTUM. Prolapsus Uteri, falling of the womb. See WOMB. Proletariate, prō-lě-tā'ri-āt, a general term applied to those Roman citizens who, in the classification of their means by Servius Tullius, stood in the sixth class, possessing less than 1,500 asses, or nothing at all. They were ever afterward distinguished by the name of capite censi, apparently because having too little means to be taxed on it, they were taxed only by head. The term has been revived in modern times as a designation of the lowest class of the community who possess no capital; and is frequently used in socialistic literature. Proloc'utor, in the Lower House of the House, and presented to the bishops who form English Convocation, a member chosen by the the Upper House as the person through whom all resolutions will be communicated to the Upper House. The prolocutor acts as chairman and moderator of the Lower House. Prologue, in dramatic poetry, (1) in the Greek drama, that part of a tragedy preceding the first appearance of the chorus. (2) In the Roman and English drama, an address to the audience preceding the piece itself. It may be either in prose or verse, and is usually pronounced by one person. Among the Romans, the player who delivered this address was called the prologus, and usually considered as a person of the drama. Thus, in the 'Amphitryon of Plautus (q.v.) Mercury appears as prologus. Prologues sometimes relate to the drama itself, and serve to explain to the audience some circumstances of the action, sometimes to the situation in which the author or actor stands to the public, and sometimes have no immediate connection with either of these persons or subjects. Shakespeare makes use of the prologue, as in 'Henry V. and the Restoration drama almost invariably employed it. It long since fell into disuse, but is occasionally revived for the effect of quaintness. PROME- PRONGBUCK Promise, Breach of. Promissory Note, is See BREACH. an unconditional Prome, prom, India, (1) a town of Lower A promise may either be verbal or written. See Burma, capital of a district of the same name, CONTRACT. on the Irawadi, about 160 miles from Rangoon by rail. It is a large town surrounded by a wall, with extensive suburbs; owing to the flat ground on which it is built it is subject to inundations from the river. It has silk-weaving and other industries, and exports silk, rice, cotton, etc. Pop. (1901) 27,375. (2) The district has an area of 2,914 square miles, and a pop. (1901) 365,860. Promessi Sposi, I, pro-měs'sē spō'zē ē, an Italian romance by Alessandro Manzoni, published in 1825, dealing with Milan under the Spanish rule of the 17th century. In fidelity to life, the interest of its principal characters, and the beauty and truth of its descriptions, it stands as the greatest Italian historical romance, and its author as the creator of a school of historical novelists. Prometheus, prō-mē'thūs, in Greek my thology, son of Iapetus the Titan and Clymene, or Themis (according to Eschylus), or Asia (according to Apollodorus). He is the legendary giver of fire and all its benefits to men. Hesiod and Eschylus, the latter of whom made his story the subject of a trilogy of which one tragedy, Prometheus Bound,' is alone extant as a whole, are our chief authority for the myth concerning Prometheus. He is represented as the brother of Atlas, Menotius, and Epimetheus. According to Eschylus, Prometheus took part with Zeus against his brother Titans and by his craft and sage counsel rendered Zeus victor, and enabled him to ascend his father's throne. Later, objecting to the plan of Zeus to destroy mankind and create a new generation of beings, he helps the weak race of mortals by stealing fire from the lightnings of Zeus and giving it in a hollow reed to men, to whom it had been till then denied. In revenge Zeus has Prometheus chained to a rock in the Caucasus by Hephaestus and his helpers Kratos and Bia, and sends a vulture to tear forever at his vitals, not allowing him to end his pain by death. Steadfastly Prometheus bears his doom, aware that in time Zeus will fall by the hand of a son born to himself and Thetis. Heracles, with the consent of Zeus, slays the vulture and releases Prometheus, who returns to Olympus and thereafter is the wise counsellor of the gods. It is in the above form that the myth has been most generally accepted, but it was varied in many ways by different poets and philosophic interpreters. His Greek name, meaning "Forethought" (that of his brother Epimetheus, signifying "Afterthought"), makes the underlying allegory apparent. Prometheus, as the friend of men, the wise helper in necessity, and in some interpretations as a rebel against unjust authority, has been much referred to in literature, and in modern times was made the subject of Shelley's 'Prometheus Unbound,' and of the fragment of a tragedy by Goethe. He has also been frequently represented in plastic art. Consult: Weiske, Prometheus und sein Mythenkreis (1842); Holle, 'Die Prometheussage (1879). Promise, an engagement entered into by one person to perform or not perform some particular thing. When there is a mutual promise between two parties it is termed a contract. The promise in writing for the payment of money Prong buck, the American pronghorned goat-antelope (Antilocapra americana), one of the two sole living representatives on the American continent of the large series of Old World antelopes (Bovida), the other being the Rocky Mountain goat (Oreamnos montanus), which is more nearly a true antelope than a goat. Although almost universally known as "antelope," the pronghorn differs so greatly from the true antelopes that it is made the type of ties alike with the giraffes, deer, and goats. The a distinct family (Antilocapride), having affinihorns, while resembling those of the true antelopes and the Bovide generally in consisting of a bone-core covered by a horny sheath, differ from those of all Bovide in the presence of a short anterior spur or branch. Furthermore they are more or less densely and extensively covered with hair, thus resembling the horns of the giraffe. But by far the most remarkable peculiarity of these horns is that they are shed annually like a deer's antlers. So skeptical were zoologists as to the possibility of a hollowhorned ruminant shedding its horns, that, although the fact was known to hunters for |