Part 16

If nitre and potassium chlorate, with other salts of nitric and chloric acids and a few similar compounds, be grouped together as oxidizing agents, most of the other materials used in making firework compositions may be classed as _oxidizable substances_. Every composition must contain at least one sample of each class: usually there are present more than one oxidizable substance, and very often more than one oxidizing agent. In all cases the proportions by weight which the ingredients of a mixture bear to one another is a matter of much importance, for it greatly affects the manner and rate of combustion. The most important oxidizable substances employed are charcoal and sulphur. These two, it is well known, when properly mixed in certain proportions with the oxidizing agent nitre, constitute gunpowder; and gunpowder plays an important part in the construction of most fireworks. It is sometimes employed alone, when a strong explosion is required; but more commonly it is mixed with one or more of its own ingredients and with other matters. In addition to charcoal and sulphur, the following oxidizable substances are more or less employed:--many compounds of carbon, such as sugar, starch, resins, &c.; certain metallic compounds of sulphur, such as the sulphides of arsenic and antimony; a few of the metals themselves, such as iron, zinc, magnesium, antimony, copper. Of these metals iron (cast-iron and steel) is more used than any of the others. They are all employed in the form of powder or small filings. They do not contribute much to the burning power of the composition; but when it is ignited they become intensely heated and are discharged into the air, where they oxidize more or less completely and cause brilliant sparks and scintillations.

Sand, potassium sulphate, calomel and some other substances, which neither combine with oxygen nor supply it, are sometimes employed as ingredients of the compositions in order to influence the character of the fire. This may be modified in many ways. Thus the rate of combustion may be altered so as to give anything from an instantaneous explosion to a slow fire lasting many minutes. The flame may be clear, smoky, or charged with glowing sparks. But the most important characteristic of a fire--one to which great attention is paid by pyrotechnists--is its _colour_, which may be varied through the different shades and combinations of yellow, red, green and blue. These colours are imparted to the flame by the presence in it of the heated vapours of certain metals, of which the following are the most important:--sodium, which gives a yellow colour; calcium, red; strontium, crimson; barium, green; copper, green or blue, according to circumstances. Suitable salts of these metals are much used as ingredients of fire mixtures; and they are decomposed and volatilized during the process of combustion. Very often the chlorates and nitrates are employed, as they serve the double purpose of supplying oxygen and of imparting colour to the flame.

The number of fire mixtures actually employed is very great, for the requirements of each variety of firework, and of almost each size of each variety, are different. Moreover, every pyrotechnist has his own taste in the matter of compositions. They are capable, however, of being classified according to the nature of the work to which they are suited. Thus there are rocket-fuses, gerbe-fuses, squib-fuses, star-compositions, &c.; and, in addition, there are a few which are essential in the construction of most fireworks, whatever the main composition may be. Such are the _starting-powder_, which first catches the fire, the _bursting-powder_, which causes the final explosion, and the _quick-match_ (cotton-wick, dried after being saturated with a paste of gunpowder and starch), employed for connecting parts of the more complicated works and carrying the fire from one to another. Of the general nature of fuses an idea may be had from the following two examples, which are selected at hazard from among the numerous recipes for making, respectively, tourbillion fire and green stars:--

_Tourbillion_. _Green Stars_. Meal gunpowder 24 parts. Potassium chlorate 16 parts. Nitre 10 " Barium nitrate 48 " Sulphur 7 " Sulphur 12 " Charcoal 4 " Charcoal 1 " Steel filings 8 " Shellac 5 " Calomel 8 " Copper sulphide 2 "

Although the making of compositions is of the first importance, it is not the only operation with which the pyrotechnist has to do; for the construction of the _cases_ in which they are to be packed, and the actual processes of packing and finishing, require much care and dexterity. These cases are made of paper or pasteboard, and are generally of a cylindrical shape. In size they vary greatly, according to the effect which it is desired to produce. The relations of length to thickness, of internal to external diameter, and of these to the size of the openings for discharge, are matters of extreme importance, and must always be attended to with almost mathematical exactness and considered in connexion with the nature of the composition which is to be used.

There is one very important property of fireworks that is due more to the mechanical structure of the cases and the manner in which they are filled than to the precise chemical character of the composition, i.e. their power of _motion_. Some are so constructed that the piece is kept at rest and the only motion possible is that of the flame and sparks which escape during combustion from the mouth of the case. Others, also fixed, contain, alternately with layers of some more ordinary compositions, balls or blocks of a special mixture cemented by some kind of varnish; and these _stars_, as they are called, shot into the air, one by one, like bullets from a gun, blaze and burst there with striking effect. But in many instances motion is imparted to the firework as a whole--to the case as well as to its contents. This motion, various as it is in detail, is almost entirely one of two kinds--_rotatory_ motion round a fixed point, which may be in the centre of gravity of a single piece or that of a whole system of pieces, and _free ascending_ motion through the air. In all cases the cause of motion is the same, viz. that large quantities of gaseous matter are formed by the combustion, that these can escape only at certain apertures, and that a backward pressure is necessarily exerted at the point opposite to them. When a large gun is discharged, it recoils a few feet. Movable fireworks may be regarded as very light guns loaded with heavy charges; and in them the recoil is therefore so much greater as to be the most noticeable feature of the discharge; and it only requires proper contrivances to make the piece fly through the air like a sky-rocket or revolve round a central axis like a Catherine wheel. Beauty of motion is hardly less important in pyrotechny than brilliancy of fire and variety of colour.

The following is a brief description of some of the forms of firework most employed:--

_Fixed Fires._--_Theatre fires_ consist of a slow composition which may be heaped in a conical pile on a tile or a flagstone and lit at the apex. They require no cases. Usually the fire is coloured--green, red or blue; and beautiful effects are obtained by illuminating buildings with it. It is also used on the stage; but, in that 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 in. 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 composition, 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 variously coloured stars, which will rise 30 ft. 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 devices and "set pieces" 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_, _Highland tartan_, _portraits_, _ships_, &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-composition, 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 Fireworks._--_Tourbillions_ are fireworks so constructed as to ascend in the air and rotate at the same time, forming beautiful 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 end, 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 horizontally 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 present only a narrow opening for the escape of the fire. The composition 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.

See Chertier, _Sur les feux d'artifice_ (Paris, 1841; 2nd ed., 1854); Mortimer, _Manual of Pyrotechny_ (London, 1856); Tessier, _Chimie pyrotechnique, ou traite pratique des feux colores_ (Paris, 1858); Richardson and Watts, _Chemical Technology_, s.v. "Pyrotechny" (London, 1863-1867); Thomas Kentish, _The Pyrotechnist's Treasury_ (London, 1878); Websky, _Luftfeuerwerkkunst_ (Leipzig, 1878). (O. M.)

FOOTNOTES:

[1] Manilius, _Astronomica_, lib. v., 438-443.

[2] Vopiscus, _Carus, Numerianus et Carinus_, ch. xix.

[3] Claudianus, _De consulatu Manlii Theodori_, 325-330.

[4] Vanuzzio Biringuccio, _Pyrotechnia_.

[5] Strutts, _Sports and Pastimes of the English People_.

[6] De Frezier, _Traite des feux d'artifice_ (1707 and 1747).

[7] _Notes and Queries_, series 5, vol. ix. p. 140, and series 8, vol. ii. pp. 145 and 254.

[8] J.B. Nichols & Sons, _London Pageants_.

[9] Hall's _Chronicles_.

[10] J. Bate, _Mysteries of Nature and Art_ (1635). This contains a picture of a green man.

[11] _Geschichte des Feuerwerkswesen_ (Berlin, 1887). The Jubilee pamphlet of the Brandenburg Artillery.

[12] See "Fairholts' Collection" bequeathed to the Royal Society of Antiquaries.

[13] _Journal_ of the Royal Artillery, vol. xxxii. No. 11.

[14] Somers' _Tracts_, vol. iii.

[15] De Frezier.

[16] Diego Ufano, _Artillery_, in Spanish (1614); Master Gunner Norton, _The Gunner_ and _The Gunner's Dialogue_ (1628); F. de Malthe (Malthus), _Artificial Fireworks_, in French and English (1628); "Hanzelet," _Recueil de plusieurs machines militaires et feux artificiels pour la guerre et recreation_ (1620 and 1630); Furttenback, master gunner of Bavaria, _Halinitro Pyrobolio_, in German (1627); (John Babington Matross, _Pyrotechnia_, 1635); Nye, master gunner of Worcester, _Art of Gunnery_ (Worcester, 1648); Casimir Siemienowitz, lieut.-general of the Ordnance to the king of Poland, _The Great Art of Artillery_, in French (1650).

[17] Translated by George Shelvocke, 1727, by order of the surveyor-general of the Ordnance.

[18] "Crace Collection" in the print-room; the King's Prints and Drawings in the library. See also "The Connection of the Ordnance Department with National and Royal Fireworks," _R. A. Journal_, vol. xxii. No. 11.

FIRM, an adjective originally indicating a dense or close consistency, hence steady, unshaken, unchanging or fixed. This word, in M. Eng. _ferme_, is derived through the French, from Lat. _firmus_. The medieval Latin substantive _firma_ meant a fixed payment, either in the way of rent, composition for periodic payments, &c.; and this word, often represented by "firm" in translations of medieval documents, has produced the English "farm" (q.v.). From a late Latin use of _firmare_, to confirm by signature, _firma_ occurs in many Romanic languages for a signature, and the English "firm" was thus used till the 18th century. From a transferred use came the meaning of a business house. In the Partnership Act 1890, persons who have entered into partnership with one another are called collectively a firm, and the name under which their business is carried on is called the firm-name.

FIRMAMENT, the sky, the heavens. In the Vulgate the word _firmamentum_, which means in classical Latin a strengthening or support (_firmare_, to make firm or strong) was used as the equivalent of [Greek: stereoma] ([Greek: stereoein], to make firm or solid) in the LXX., which translates the Heb. raqiya'. The Hebrew probably signifies literally "expanse," and is thus used of the expanse or vault of the sky, the verb from which it is derived meaning "to beat out." In Syriac the verb means "to make firm," and is the direct source of the Gr. [Greek: stereoma] and the Lat. _firmamentum_. In ancient astronomy the firmament was the eighth sphere containing the fixed stars surrounding the seven spheres of the planets.

FIRMAN (an adaptation of the Per. _ferman_, a mandate or patent, cognate with the Sanskrit _pramana_, a measure, authority), an edict of an oriental sovereign, used specially to designate decrees, grants, passports, &c., issued by the sultan of Turkey and signed by one of his ministers. A decree bearing the sultan's sign-manual and drawn up with special formalities is termed a _hatti-sherif_, Arabic words meaning a line, writing or command, and lofty, noble. A written decree of an Ottoman sultan is also termed an _irade_, the word being taken from the Arab. _irada_, will, volition, order.

FIRMICUS, MATERNUS JULIUS, a Latin writer, who lived in the reign of Constantine and his successors. About the year 346 he composed a work entitled _De erroribus profanarum religionum_, which he inscribed to Constantius and Constans, the sons of Constantine, and which is still extant. In the first part (chs. 1-17) he attacks the false objects of worship among the Oriental cults; in the second (chs. 18-29) he discusses a number of formulae and rites connected with the mysteries. The whole tone of the work is fanatical and declamatory rather than argumentative, and is thus in such sharp contrast with the eight books on astronomy (Libri VIII. _Matheseos_) bearing the same author's name, that the two works have usually been attributed to different writers. Mommsen (_Hermes_ vol. 29, pp. 468-472) has, however, shown that the astronomy--a work interfused with an urbane Neoplatonic spirit--was composed about 336 and not in 354 as was formerly held. When we add to this the similarity of style, and the fact that each betrays a connexion with Sicily, there is the strongest reason for claiming the same author for the two books, though it shows that in the 4th century acceptance of Christianity did not always mean an advance in ethical standpoint.

The Christian work is preserved in a Palatine MS. in the Vatican library. It was first printed at Strassburg in 1562, and has been reprinted several times, both separately and along with the writings of Minucius Felix, Cyprian or Arnobius. The most correct editions are those by Conr. Bursian (Leipzig, 1856), and by C. Halm, in his _Minucius Felix_ (_Corp. Scr. Eccl. Lat._ ii.), (Vienna, 1867). The Neoplatonist work was first printed by Aldus Manutius in 1501, and has often been reprinted. For full discussions see G. Ebert, _Gesch. der chr. lat. Litt._, ed. 1889, p. 129 ff.; O. Bardenhewer, _Patrologie_, ed. 1901, p. 354.

FIRMINY, a town of central France in the department of Loire, 8 m. S.W. of St Etienne by rail. Pop. (1906) 15,778. It has important coal mines known since the 14th century and extensive manufactures of iron and steel goods, including railway material, machinery and cannon. Fancy woollen hosiery is also manufactured.

FIRST-FOOT, in British folklore, especially that of the north and Scotland, the first person who crosses the threshold on Christmas or New Year's Eve. Good or ill luck is believed to be brought the house by First-Foot, and a female First-Foot is regarded with dread. In Lancashire a light-haired man is as unlucky as a woman, and it became a custom for dark-haired males to hire themselves out to "take the New Year in." In Worcestershire luck is ensured by stopping the first carol-singer who appears and leading him through the house. In Yorkshire it must always be a male who enters the house first, but his fairness is no objection. In Scotland first-footing was always more elaborate than in England, involving a subsequent entertainment.

FIRST OF JUNE, BATTLE OF THE. By this name we call the great naval victory won by Lord Howe over the French fleet of Admiral Villaret-Joyeuse, on the 1st of June 1794. No place name can be given to it, because the battle was fought 429 m. to the west of Ushant.