Page:Encyclopædia Britannica, Ninth Edition, v. 20.djvu/148

Rh 136 P Y R P Y R case, the composition must be such as to give no suffocating or poisonous fumes. Bengal lights are very similar, but are piled in saucers, covered with gummed paper, and lit by means of pieces of match. Marroons are small boxes wrapped round several times with lind cord and filled with a strong composition which explodes with a loud report They are generally used in batteries, or in combination with some other form of firework. Squibs are straight cylindrical cases about 6 inches long, firmly closed at one end, tightly packed with a strong composition, and capped with touch -paper. Usually a little bursting-powder is put in before the ordinary com- position, so that the fire is finished by an explosion. The character of the fire is, of course, susceptible of great variation in colour, &c. Crackers are characterized by the cases being doubled backwards and forwards several times, the folds being pressed close and secured by twine. One end is primed ; and when this is lit the cracker burns with a hissing noise, and a loud report occurs every time the fire reaches a bend. If the cracker is placed on the ground, it will give a jump at each report ; so that it cannot quite fairly be classed among the fixed fireworks. Roman candles are straight cylindrical cases filled with layers of composition and stars alternately. These stars are simply balls of some special composition, usually containing metallic filings, made up with gum and spirits of wine, cut to the required size and shape, dusted with gunpowder, and dried. They are discharged like blazing bullets several feet into the air, and produce a beautiful effect, which may be enhanced by packing stars of differently coloured fire in one case. Gerbes are choked cases, not unlike Roman candles, but often of much larger size. Their fire spreads like a sheaf of wheat. They may be packed with vari- ously coloured stars, which will rise 30 feet or more. Lances are small straight cases charged with compositions like those used for making stars. They are mostly used in complex devices, for which purpose they are fixed with wires on suitable wooden frames. They are connected by leaders, i.e., by quick -match enclosed in paper tubes, so that they can be regulated to take fire all at the same time, singly, or in detachments, as may be desired. The de- vices constructed in this way are often of an extremely elaborate character ; and they include all the varieties of lettered designs, of fixed suns, fountains, palm-trees, waterfalls, mosaic work, High- land tartan, &c. Rotating Fireworks. Pin or Catherine wheels are long paper cases filled with a composition by means of a funnel and packing- wire and afterwards wound round a disk of wood. This is fixed by a pin, sometimes vertically and sometimes horizontally ; and the outer primed end of the spiral is lit. As the fire escapes the recoil causes the wheel to revolve in an opposite direction and often with considerable velocity. Pastiles are very similar in principle and construction. Instead of the case being wound in a spiral and made to revolve round its own centre point, it may be used as the engine to drive a wheel or other form of framework round in a circle. Many varied effects are thus produced, of which the fire- wheel is the simplest. Straight cases, filled with some fire-com- position, are attached to the end of the spokes of a wheel or other mechanism capable of being rotated. They are all pointed in the same direction at an angle to the spokes, and they are connected together by leaders, so that each, as it burns out, fires the one next it. The pieces may be so chosen that brilliant effects of changing colour are produced ; or various fire-wheels of different colours may be combined, revolving in different planes and different directions some fast and some slowly. Bisecting wheels, plural wheels, caprice wheels, spiral wheels, are all more or less complicated forms ; and it is possible to produce, by mechanism of this nature, a model in fire of the solar system. Ascending Fireioorks. Tourbillions are fireworks so constructed as to ascend in the air and rotate at the same time, forming beauti- ful spiral curves of fire. The straight cylindrical case is closed at the centre and at the two ends with plugs of plaster of Paris, the composition occupying the intermediate parts. The fire finds vent by six holes pierced in the case. Two of these are placed close to the ends, but at opposite sides, so that one end discharges to the right and the other to the left ; and it is this which imparts the rotatory motion. The other holes are placed along the middle line of what is the under-surface of the case when it is laid horizon- tally on the ground ; and these, discharging downwards, impart an upward motion to the whole. A cross piece of wood balances the tourbillion ; and the quick-match and touch-paper are so arranged that combustion begins at the two ends simultaneously and does not reach the holes of ascension till after the rotation is fairly begun. The sky-rocket is generally considered the most beautiful of all fireworks; and it certainly is the one that requires most skill and science in its construction. It consists essentially of two parts, the body and the head. The body is a straight cylinder of strong pasted paper and is choked at the lower end, so as to pre- sent only a narrow opening for the escape of the fire. The com- position does not fill up the case entirely, for a central hollow conical bore extends from the choked mouth up the body for three quarters of its length. This is an essential feature of the rocket. It allows of nearly the whole composition being fired at once ; the result of which is that an enormous quantity of heated gases collects in the hollow bore and the gases, forcing their way downwards through the narrow opening, urge the rocket up through the air. The top of the case is closed by a plaster-of- Paris plug. A hole passes through this and is filled with a fuse, which serves to communicate the fire to the head after the body is burned out. This head, which is made separately and fastened on after the body is packed, consists of a short cylindrical paper chamber with a conical top. It serves the double purpose of cutting a way through the air and of holding the garniture of stars, sparks, crackers, serpents, gold and silver rain, &c., which are scattered by bursting fire as soon as the rocket reaches the highest point of its path. A great variety of beautiful effects may be obtained by the exercise of ingenuity in the choice and construction of this garniture. Many of the best results have been obtained by unpublished methods which must be regarded as the secrets of the trade. The stick of the sky-rocket serves the purpose of guiding and balancing it in its flight ; and its size must be accurately adapted to the dimensions of the case. In winged rockets the stick is replaced by cardboard wings, which act like the feathers of an arrow. A girandole is the simultaneous discharge of a large number of rockets (often from one hundred to two hundred), which either spread like a peacock's tail or pierce the sky in all directions with rushing lines of fire. This is usually the final feat of a great pyrotechnic display. For a description of rockets used in war, see AMMUNITION. See Chertier, Sur Us Feux d' Artifice (Paris, 1841 ; 2d ed. 1854) ; Mortimer, Manual of Pyrotechny (London, 1856); Tessier, Chimie pyrotechnique, ou Tmitr. pratique des Feux Colores (Paris, 1858) ; Richardson and Watts, Chemical Tech- nology, s.v. "Pyrotechny" (London, 1863-67); Thomas Kentish, The Pyro- technist's Treasury (London, 1S78); Websky, Luflfeuem-erkkunst (Leipsic, 1878). (O. M.) PYRRHO. See SCEPTICISM. PYRRHUS. The name of Pyrrhus, king of Epirus, owes its chief fame in history to the fact that with his invasion of Italy in the early part of the 3d century B.C. Greece and Rome for the first time came definitely into contact. Born about the year 318, and claiming descent from Pyrrhus, the son of Achilles, connected also with the royal family of Macedonia through Olympias, the mother of Alexander the Great, he became when a mere stripling king of the wild mountain tribes of Epirus, and learned how to fight battles in the school of Demetrius Poliorcetes (the Besieger) and of his father Antigonus. He fought by their side in his seventeenth year at the memorable battle of Ipsus in Phrygia, in which they were decisively defeated by the combined armies of Seleucus and Lysi- machus. Soon afterwards he was sent to the court of Ptolemy of Egypt at Alexandria as a pledge for the faith- ful carrying out of a treaty of alliance between Ptolemy and Demetrius, as his sister Deidamia was the wife of the latter. Through Ptolemy, whose step-daughter Antigone he married, he was enabled to establish himself firmly on the throne of Epirus, and he became a formidable opponent to Demetrius, who was now king of Macedonia and the leading man in the Greek world. He won a victory over one of Demetrius's generals in JEtolia, invaded Macedonia, and forced Demetrius to conclude a truce with him. For a brief space of about seven months he had possession of a large part of Macedonia, Demetrius finding it convenient to make this surrender on condition that Pyrrhus did not meddle with the affairs of the Peloponnesus. But in 286 he was defeated by Lysimachus at Edessa, driven out of Macedonia, and compelled to fall back on his little king- dom of Epirus. In 280 came the great opportunity of his life, the embassy from the famous Greek city Taren- tum in southern Italy with a request for aid against Rome, whose hostility the Tarentines had recklessly pro- voked. Pyrrhus had a trusted friend and adviser in Cineas of Thessaly, a persuasive speaker and a clever diplomatist, and he at once sent him over with 3000 men to Tarentum with a view to prepare matters. He himself soon fol- lowed, after a disastrous passage across the Adriatic, with a miscellaneous force, furnished him partly by the assistance of Ptolemy, of about 25,000 men, with some elephants, his best troops being some Macedonian infantry and Thessalian cavalry. He had counted on an army of Italian mercenaries, but the Tarentines and the Italian Greeks