It is useless to inquire in what way man first discovered that fire was subject to his control, and could even be called into being by appropriate means. With the natural phenomenon and its various aspects he must soon have become familiar. The volcano lit up the darkness of night and sent its ashes or its lava down into the plains; the lightning or the meteor struck the tree, and the forest was ablaze; or some less obvious cause produced some less extensive ignition. For a time it is possible that the grand manifestations of nature aroused no feelings save awe and terror; but man is quite as much endowed with curiosity as with reverence or caution, and familiarity must ere long have bred confidence if not contempt. It is by no means necessary to suppose that the practical discovery of fire was made only at one given spot and in one given way; it is much more probable indeed that different tribes and races obtained the knowledge in a variety of ways. We still find in different parts of the world the natives taking advantage of hot springs, naphtha or petroleum wells, and accessible craters. In the island of Tanna, for instance, there is a mountain to the west of Port Resolution which abounds in evidence of its volcanic character—in fissures, steam-jets, hot-springs, &c. The inhabitants, says the Rev. George Turner, have not the slightest apprehension of danger; their settlements are arranged so that their murum or public square occupies one of the “hot places of the mountain; and there they lounge and enjoy the subterranean heat. Some of the springs reach the boiling point. Every day women may be seen cooking vegetables in artificial pits which form a series of never failing boiling pots. In some places the men or boys have only to stand on the rocks, spear their fish, and pitch them behind into the hot springs.” Similar accounts are given of the Maories in New Zealand, and the Negritos in the New Hebrides.

It has been asserted of many tribes that they would be unable to rekindle their fires if they were all allowed to die out. Travellers in Australia and Tasmania depict the typical native woman bearing always about with her a burning brand, which it is one of her principal duties to protect and foster; and it has been supposed that it was only ignorance which imposed on her the endless task. This, however i is not so certain; for Mr Miklucho Maclav remarks of the Papuans, whom he has closely studied, that though they know how to produce fire, they prefer to carry it about. It was one of the distinguishing marks of the Samoan noble that his fire was never permitted to go out; and his attendants had a special name from their business of watching it while he slept. In Corea the preservation of the ancestral fire is still regarded as of the first importance for the happiness of a family, and the same belief has had a very extensive sway in other parts of the world.

The methods employed for producing fire vary considerably in detail, but are for the most part merely modified applications of concussion or friction. Sir John Lubbock has remarked that the working up of stone into implements must have been followed sooner or later by the discovery of fire; for in the process of chipping sparks were elicited, and in the process of polishing heat was generated. The first or concussion method is still familiar in the flint and steel, which has hardly passed out of use even in the most civilized countries. Its modifications are comparatively few and unimportant. The Alaskans and Aleutians take two pieces of quartz, rub them well with native sulphur, strike them together till the sulphur catches fire, and then transfer the flame to a heap of dry grass over which a fevz feathers have been scattered. Instead of two pieces of quartz the Eskimos use a piece of quartz and a piece of iron pyrites. Mr Frederick Boyle saw fire produced by striking broken china violently against a bamboo, and Bastian observed the same process in Burmah, and Wallace in Ternate. In Cochin China two pieces of bamboo are considered sufficient, the silicious character of the outside layer rendering it as good as native flint The friction methods are more various. One of the simplest is what Mr Tylor calls the stick and groove—“a blunt pointed stick being run along a groove of its own making in a piece of wood lying on the ground.” Much, of course, depends on the quality of the woods and the expertness of the manipulator. In Tahiti Mr Darwin saw a native produce fire in a few seconds, but only succeeded himself after much labour. The same device was employed in New Zealand, the Sandwich islands, Tonga, Samoa, and the Radack. ' islands. Instead of rubbing the movable stick backwards and forwards other tribes make it rotate rapidly in a round hole in the stationary piece of wood—thus making what Mr Tylor has happily designated a fire-drill. This device has been observed in Australia, Kamchatka, Sumatra, and the Carolines, among the Veddahs of Ceylon, throughout a great part of Southern Africa, among the Eskimo and Indian tribes of North America, in the West Indies, in Central America, and as far south as the Straits of Magellan. It was also employed by the ancient Mexicans, and Mr Tylor gives a quaint picture of the operation from a Mexican MS.,—aman half kneeling on the ground is causing the stick to rotate between the palms of his hands. This simple method of rotation seems to be very generally in use; but various devices have been resorted to for the purpose of diminishing the labour and hastening the result. The Gaucho of the Pampas takes “an elastic stick about 18 inches long, presses one end to his breast and the other in a hole in a piece of wood, and then rapidly turns the curved part like a carpenter’s centre-bit” In other cases the rotation is effected by means of a cord or thong wound round the drill and pulled alternately by this end and that. In order to steady the drill the Eskimo and others put the upper end in a socket of ivory or bone which they hold firmly in their mouth. A further advance was made by some of the North American Indians, who appear to have applied the principle of the bow-drill; and the still more ingenious pump-drill was used by the Iroquois Indians. For full descriptions of these instruments and a rich variety of details connected with fire-making we must refer the reader to Mr Tylor’s valuable chapter in his Rc∙ searches. These methods of producing fire are but rarely used in Europe, and only in connexion with superstitious observances. We read in Wuttke that some time ago the authorities of a Mecklenburg village ordered a “wild fire " to be lit against a murrain amongst the cattle. For two hours the men strove vainly to obtain a spark, but the fault was not to be ascribed to the quality of the wood, or to the dampness of the atmosphere, but to the stubbornness of an old lady, who, objecting to the superstition, would not put out her night lamp; such a fire, to be efficient, must burn alone. At last the strong-minded female was compelled to give in; fire was obtained,—but of bad quality, for it did not stop the murrain.

It has long been known that the rays of the sun might be concentrated by a lens or concave mirror. Aristophanes mentions the burning-lens in The Clouds, and the story of Archimedes using a mirror to fire the ships at Syracuse is familiar to every schoolboy. If Garcilasso de la Vega can be trusted as an authority, the Virgins of the Sun in Peru kindled the sacred fire with a concave cup set in a great bracelet. In China the burning-glass is in common use.

To the inquiry how mankind became possessed of fire, the cosmogonies, those records of pristine speculative thought, do not give any reply which would not be found in the relations of travellers and historians.

They say in the Tonga Islands that the god of the earthquakes is likewise the god of fire. At Mangala it is told that the great Maui went down to hell, where he surprised the secret of making fire by rubbing two pieces of wood together. The Maoris tell the tale differently. Maui had the fire given to him by his old blind grandmother, Mahuika, who drew it from the nails of her hands. Wishing to have a stronger one, he pretended that it had gone out, and so he obtained fire from her great toe. It was so fierce that every thing melted before the glow; even Maui and the grandmother herself were already burning when a deluge, sent from heaven, saved the hero and the perishing world; but before the waters extinguished all the blaze, Mahuika shut a few sparks into some trees, and thence men draw it now. The Maories have also the legend that thunder is the noise of Tawhaki’s footsteps, and that lightnings flash from his armpits. At Western Point, Victoria, the Australians say the good old man Pundyil opened the door of the sun, whose light poured then on earth, and that Karakorok, the good man’s good daughter, seeing the earth to be full of serpents, went everywhere destroying serpents; but before she had killed them all, her staff snapped in two, and while it broke, a flame burst out of it. Here the serpent-killer is a fire-bringer. In the Persian Shahnainah also fire was discovered by a dragon-fighter. Hushenk, the powerful hero, hurled at the monster a prodigous stone, which, evaded by the snake, stfuck a rock and was splintered by it. ‘ ‘ Light shone from the dark pebble, the heart of the rock flashed out in glory, and fire was seen for the first time in the world.” The snake escaped, but the mystery of fire had been revealed.

North American legends narrate how the great buffalo, careering through the plains, makes sparks flit in the night, and sets the prairie ablaze by his hoofs hitting the rocks. We meet the same idea in the Hindu mythology, which conceives thunder to have been, among many other things, the clatter of the solar horses on the Akmon or hard pavement of the sky. The Dakotas claim that their ancestor obtained fire from the sparks which a friendly panther struck with its claws, as it scampered upon a stony hill.

Tohil, who gave the Quiches fire by shaking his sandals, was, like the Mexican Quetzelcoatl, represented by a flint stone. Gua-mansuri, the father of the Peruvians, produced the thunder and the lightning by hurling stones with his sling. The thunderbolts are his children. Kudai, the great god of the Altaian Tartars, disclosed “the secret of the stone’s edge and the iron’s hardness.” The Slavonian god of thunder was depicted with a silex in his hand, or even protruding from his head. The Lapp Tiennes struck with his hammer upon his own head; the Scandinavian Thor held a mallet in one hand, a flint in the other. Taranis, the Gaul, had upon his head a huge mace sun ’ ounded by six little ones. Finnish poems describe how “fire, the child of the sun, came down from heaven, where it was rocked in a tub of yellow copper, in a large pail of gold.” Ukko, the Esthonian god, sends forth lightnings, as he strikes his stone with his steel. According to the Kalewala, the same mighty Ukko struck his sword against his nail, and from the nail issued the “fiery babe.” He gave it to the Wind’s daughter to rock it, but the unwary maiden let it fall in the sea, where it was swallowed by the great pike, and fire would have been lost for ever, if the child of the sun had not come to the rescue. He dragged the great pike from the water, drew out his entrails, and found there the heavenly spark still alive. Hephaestus also, the Greek fire god, fell from heaven into the sea of Lemnos. Prometheus brought to earth the torch he had lighted at the sun’s chariot.

Human culture may be said to have begun with fire, of which the uses increased in the same ratio as culture itself. To save the labour expended on the initial process of procuring light, or on carrying it about constantly, primitive men hit on the expedient of a fire which should burn night and day in a public building. The Egyptians had one in every temple, the Greeks, Latins, and Persians in all towns and villages. The Natchez, the Mexicans, the Mayas, the Peruvians, had their “national fires” burning upon large pyramids. Of these fires the “eternal lamps” in the synagogues, in the Byzantine and Catholic churches, may be a survival. The “Regia,” Rome’s sacred centre, supposed to be the abode of Vesta, stood close to a fountain; it was convenient to draw from the same spot the two great requisites, fire and water. All civil and political interests grouped themselves around the Prytaneion which was at once a temple, a tribunal, a town-hall, and a gossiping resort; all public business and most private affairs were transacted by the light and in the warmth of the common fire. No wonder that its flagstones should become sacred. Primitive communities consider as holy everything that ensures their existence and promotes their welfare, material things such as fire and water not less than others. Thus the Prytaneion grew into a religious institution. And if we hear a little more of fire worship than of water worship, it is because fire, being on the whole more difficult to obtain, was esteemed more precious.

We have curious and concordant testimonies that the principal functions of the state itself grew out of the care which was bestowed on the tribal fire. The men who attended it in Hellas were called the Prytanes. They had to eat together, and it would have been considered as a bad omen if they had neglected that duty. They were fed at the public expense; and well they might be, for having been, probably, general cooks at the outset, they became, when the city was established, Archontes or magistrates, and even Basileis, or a combination of the captain, the priest, and the king. Thus the first guardians of the tribal fire were the earliest public servants, who by degrees appropriated all important offices, as the state itself developed into a vast aggregation of interests. And when Augustus usurped the Roman empire, he assumed all the powers which a pristine board of flamens, or of Prytanes, may have possessed. He made himself Pontifex Maximus, and assumed the charge of the public fire; and on transporting it to his own palace, he had to convert it into public property. The Hellenic nations, as well as the Aztecs, received ambassadors in their temples of fire, where, as at the national hearth, they feasted the foreign guests. The Prytaneion and the state were convertible terms. If by chance the fire in the Roman temple of Vesta was extinguished, all tribunals, all authority, all public or private business, had to stop immediately. The connexion between heaven and earth had been broken, and it had to be restored in some way or other,—either by Jove sending down divine lightning on his altars, or by the priests making a new fire by the old sacred method of rubbing two pieces of wood together, or by catching the rays of the sun in a concave mirror. No Greek or Roman army crossed the frontier without carrying an altar where the fire taken from the Prytaneion burned night and day. When the Greeks sent out colonies the emigrants took with them living coals from the altar of Hestia, and had in their new country a fire lit as a representative of that burning in the mother country. Not before the three curiae united their fires into one could Rome become powerful; and Athens became a shining light to the world only, we are told, when the twelve tribes of Attica, led by Theseus, brought each its brand to the altar of Athene Polias. All Greece confederated, making Delphi its central hearth; and the islands congregated around Delos, whence the new fire was fetched every year.

According to a not impossible theory, all architecture, public and private, sacred and profane, began with the erection of sacred sheds to protect the sacred fire, which abodes men dared to inhabit only after a length of time. For it must be borne in mind that fire was looked upon as a divinity. We are expressly told that Vesta had no image or statue even in her own temple, the Vestal fire being considered as the very goddess herself. The husbandmen who ate their repast before the hearth believed, as Ovid relates, that they sat in the presence of the gods themselves. The hearth fire was kept holy, its flame was to remain bright and pure. The minute and irksome prescriptions of the Zend-Avesta carried this feeling to the extreme: it was and it is still a widely spread belief that nothing unclean is to be thrown in the fire, that no indecent actions are to be committed before it. To spit in one’s fire would be now considered in many places, in Albania, for example, as an unpardonable offence. The Galtchas of Ferghana, according to Μ. de Ujfalvy, are so reverential that they would not blow out a light lest they should render the flame impure with their breath; and a similar peculiarity was observed by Wood in Badakshan and by Khanikoff among the Tadjiks of Bokhara.

In the course of time, the same reasons which made the tribe provide itself with a permanent...

Still more recently Cornwall has become the seat of the manufacture, where, as at Calstock, Tregoning Hill near Breage, St Ednor near St Columb, and Lee Moor, fire-bricks of fine quality are made from china-clay refuse and disintegrated granite. Mr Argall of the Tregoning Hill Company states that the locality was one of the first seats of china-clay mining between the years 1730 and 1750, and that in 1862 the present company commenced to make fire-bricks and tiles from the refuse of the clays, taking about two-thirds of silica and one-third of mica, which are mixed together in a pug mill, moulded and burnt in round ovens holding about 16,000 bricks, and that a very superior fire-brick is made from clay direct from the “stopes,” containing [table]

which are employed by founders, smelters, gas companies, &c. The price paid at the works is from 50s. to 55s. per 1000. The source of the materials is decomposed granite, of which Tregoning Hill consists.

The Hingston Down fire-clay deposit, near Calstock, supplying the Calstock fire-brick works, the Phaenix works, and the Tamar works in the same neighbourhood, consists of a range of decomposed granite with an average width of three-quarters of a mile, running east and west for 3 or 4 miles, extending to an ascertained depth of from 300 to 400 feet, and intersected by mineral lodes. The Calstock Fire-Brick Company (limited), superintended by Mr C. B. Evate, commenced operations in the year 1870, and manufactured from the decomposed granite fire-bricks of a highly refractory character, which are delivered free on board at the port of Calstock at from 50s. to 60s. a thousand, weighing about 3¾ tons. Another source of firebrick material, scarcely yet developed, is the pockets or depressions occurring in the mountain limestone of North Wales, Derbyshire, and Ireland, containing white refractory clays and sands, the insoluble remnants from the local dissolution of the limestone, intermixed with the debris of the overlying millstone grit. These clays and sands when evenly mingled are sufficiently adhesive to k be moulded, and their small contractility and highly refractory character render them pre-eminently suitable for fire-brick manufacture. Fire-brick works have already been established on the estate of Captain Cooke of Colomendy Hall, near Mold, and the refractory clays and sands are largely employed for lining furnaces, 3000 tons having been sold for this purpose alone in the year 1877.

The fire-clays of the Coal-Measures vary as regards their refractory character, not only in the different coal-fields, but the individual strata in close alternation often present sudden variations, refractory beds being interstratified with useless strata largely charged with disseminated carbonate of iron. The grey colour of the Coal-Measure clays is partially due to the presence of this mineral, which, whether disseminated through the mass or otherwise occurring in excess as concretionary nodules, is prejudicial to the clays as a material for fire-bricks. Carbonaceous matter is also present in variable proportions, colouring the clay from a slaty-black to a pale grey, but as this is eliminated in the earlier stages of the burning of the bricks, its presence in no way influences their refractory character.

The relative proportion of silica and alumina which some manufacturers have laid undue stress upon as indicating heat-resisting quality is of little moment, as both these constituents, whether occurring in combination as silicates of alumina, or as free alumina and silica, are essentially the refractory elements of all good fire-bricks, being unvitrifiable per se, excepting when associated with the alkalies, lime, or oxides of iron. The plastic character of refractory clays is also of limited influence on their suitability for fire-brick manufacture; extreme plasticity, which is generally accompanied by excessive contractility and vitrifiability, is prejudicial. As a rule few clays or materials used in the manufacture of fire-bricks are insufficiently plastic to prevent their being easily moulded, and in the manufacture by the dry process, or the compression of the brick out of nearly dry pulverized clay, plasticity is not so essential a quality. As regards chemical composition the following analyses indicate its general character, and the variability of the proportion of the constituents of some of the more important fire-clays :— [table]

The above analyses indicate a preponderance of silica in the Coal-Measure fire-clays compared with the Tertiary clays of Devon and Dorset, in which a larger proportion of alumina occurs. The latter character is accompanied by tenacity and plasticity, and greater contraction in drying and burning, which, when excessive, is counteracted by mingling with the clay sand and ground burnt clay or sherds.

Contractility.— The contraction in burning (excluding the contraction in drying) of several Coal-Measure fire-clays pressed out of nearly dry pulverized clay was ascertained by the writer to be as follows:— [table]

The average contraction of the Coal-Measure fire-clays is thus little over two per cent. A brick manufactured from the best Stourbridge clay without admixture of burnt material contracted seven-eighths of an inch in nine inches, but this would probably represent the contraction both in drying and burning. The contraction in burning of the Tertiary fire-clays used for the manufacture of fire-bricks in Devon and Dorset is much more than that of the Coal Measure clays [table]

The clays above enumerated are not exclusively used for fire-brick manufacture, but fairly indicate the general character of the Tertiary fire-brick clays, which, compared with the Coal-Measure fire-clays, are characterized by a preponderance of alumina, tenacity of texture, contractility in the kiln, and an absence of iron and the alkalies, <fcc., which tend to vitrification. Tenacity of texture in a fire-brick material is, however, a mechanical condition, which, caeteris paribus, assists vitrification, a coarse open body being more refractory than a close homogeneous brick of similar chemical composition. A well manufactured brick should be of a pale cream or clear buff colour, uniform throughout its mass, and burnt to the full extent of its contractility.

The chemical changes which take place in the burning consist, first, of the destruction of the disseminated carbonaceous matter, the dehydration of the silicates of alumina, destroying their plastic character, and the decomposition of the disseminated carbonate of protoxide of iron, converting it into anhydrous sesquioxide, to which the yellow colour of the burnt brick is due; if the burning is carried to a high state of vitrification the yellow tint is replaced by a dull grey, due to the partial reduction of the sesquioxide of iron and its conversion into silicate of protoxide or minutely disseminated particles of metallic iron; any alkalies present also form vitreous combinations with the silica during the latter stages of the burning. The paleness of colour of a fire-brick is not always a safe indication of the absence of iron, as the presence of a large proportion of carbonaceous matter in the clay tends to bleaching by the reduction of the colouring sesquioxidc to a lower oxide preserved as a silicate in a comparatively colourless condition. Again, the presence of lime and the other alkaline earths, which are disadvantageous fluxing elements, will cloak the colouring power of a large pér-centage of oxide of iron by the formation of a pale double silicate of lime and iron. This is taken advantage of in the manufacture of buff building bricks by mixing ground chalk with ferruginous clays which would otherwise burn dark red.

A properly burnt brick, uniform in colour throughout its mass, can only be obtained by slow progressive firing; a broken brick that has been too quickly burnt, though pale on the surface, presents a darker central patch and concentric rings of various shades of colour, due mainly to the different states of oxidation of the iron, and partly to the presence of unconsumed carbonaceous matter; but the chemistry of this colour-variegation is not clearly understood.

Durability of Fire-Bricks.— The destruction and wearing out of a fire-brick in its ordinary uses takes place in different ways. First, it may waste by crumbling and shattering; this occurs only when the brick is unnecessarily porous in texture, or from the presence of extraneous lumps of foreign materials, such as small pebbles and fragments of lime and iron-stone, which the manufacturer endeavours to get rid of by sifting or crushing before the clay is moulded. Secondly, the gradual vitrification of the brick under the pressure of the superimposed structure distorts its form, and the semiplastic red-hot or white-hot mass is gradually squeezed out of shape, and has to be periodically replaced in the hotter parts of the furnaces and kilns. However completely a brick has been burnt, bringing its dimensions almost to the limit of contractility, constant exposure to long-continued heat still further reduces its bulk, causing the displacement of the mass of which it forms a part, aud necessitating replacement and repairs. Thirdly, there is the gradual fretting away of the exposed brick surface by vitrification, however refractory a brick may be; when it lines flues and furnaces, the fumes and ashes incessantly carried into contact with it bring foreign accessions, which vitrify the exposed portions and form a coating of viscid slag, which eats into the brick surface, creeping down and clogging the flues and fire-holes with a vitreous mass. In the case of blast-furnaces the fretting away of the surface of the fire-brick linings gradually enlarges their capacity, the surface destruction decreasing from the tweers upwards, the faces opposite the impact of the blast being distinctly excavated beyond the outline of the enlarged circumference. In one of the furnaces of the Madeley Wood Company, Madeley, Shropshire, “blown in” in 1867 and “blown out” in 1874, the diameter at the base, originally 3 feet, had been enlarged to about 7 feet 6 inches, and at the widest part, a little below the middle, from 12 feet, its original diameter, to 13 feet. In another furnace, after ten years’ blast, the original diameter of 4 feet 5 inches at the base had been enlarged to 9 feet 6 inches; at a third of its height from 9 feet 11 inches to 12 feet; and half way up, from 11 feet 9 inches to 12 feet 10 inches, the destruction of bnck-surface gradually decreasing towards the top, where the increase of size was but trifling. This would represent a consumption of brick-surface of from 3 to 4 inches a year at the tweers, and about three-quarters of an inch a year towards the middle of the furnace.

It is beyond the scope of this article to enter into the details of fire-brick manufacture, which in its main features resemble the manufacture of building bricks, except that fire-bricks are rarely if ever burnt in clamps.

Properly constructed ovens on the “down draft” principle, with the outlet from the bottom into a tall chimney, are now almost universally employed, as they ensure greater regularity in the burning than in the old form of kiln, with a direct escape from the top, as well as economy in fuel. The consumption of coal varies from 9 to 15 cwt. per 1000 bricks, exclusive of the coal used in the drying stoves.

Coal-Measure fire-clays are often mined in an almost rocky condition, requiring long exposure to the weather to effect their disintegration. The softer clunches or clays are sometimes prepared for the moulder by “weathering,” but the more common practice is to grind the fire-clay just as it comes from the pit under heavy “runners” or rollers, effecting a granular texture which is a desirable quality in a refractory brick. It is now becoming a common practice to grind up with the raw clay from onefourth to one-third of its weight of broken burnt sherds or fire-bricks. All waste materials are thus utilized, and the excessively contractile character of highly plastic clays such as those of Dorsetshire is counteracted. Silicious sand is also sometimes mixed with the more plastic clays to reduce their contractility.

The ground clay is either brought into a plastic state with water in a pug-mill and moulded by hand, or by brickmoulding machinery generally connected with the pug-mill outlet; or the partially moist ground-clay dust is compressed into bricks in iron moulds by steam power, a modification of Prosser’s well-known process. More shapely bricks are thus produced than by plastic moulding, and their perfectly true flat sides enable a minimum of jointing materials to be employed—a circumstance of importance in the stability of fire-brick masonry, as thick fireclay jointing contracts in the firing, tending to shatter tho structure.

In addition to the use of fire-clay for the bedding of all fire-brick structures, it forms the materials of gas retorts, crucibles, and every kind of potter’s kiln furniture, such as saggars, cranks, slip kiln bottoms, enamel kiln linings, &c. These have been up to within the last year or two moulded out of plastic clay, but by processes and machinery recently patented by Mr A. Maw, saggars, cranks, and every kind of kiln furniture can be moulded out of nearly dry pulverized clay, at a great reduction in cost below that of the plastic process, and the exact regularity of form attained effects a large saving of space in the ovens and kilns. Moreover, the even bearing on each other of the regularly-shaped saggars when piled up in the oven, reduces the “wear and tear” and breakage to a minimum. Fire-bricks vary much in price in the different producing districts,— about 40s. per 1000 may now be looked upon as a minimum, ranging up to 70s. and 80s., further augmented by the cost of carriage to other districts. A thousand fire-bricks weigh from 3¾ to 4 tons. (g. μ.)