This article embraces the modern methods devised for preventing, limiting, and extinguishing fires, and may be conveniently divided into the following sections: - Buildings, Extinguishing Compounds, Paints, Textiles, Timber, Writing Materials.

The following observations are due to Capt. Shaw: -

To construct a building in such a way lhat it will resist the effects of heat and flame for any considerable time requires care and forethought in the choice of the position, a sound knowledge of the several materials to be used, and a skilful design to bring these materials into combination in such a way as to meet the proposed requirements of the structure when completed, and at the same time to avoid the consequences of extreme and sudden changes of temperature; for it should be known that some of the greatest destruction ever seen after a conflagration has been caused, not by the primary, but by the secondary effects of fire; that is to say, not by the expansion produced by heat, but by sudden contraction after the expansion. In choice of materials there is much food for reflection in connection with the safety of buildings when exposed to sudden changes of temperature. In walls, bricks of any kind, but more particularly fire-bricks, if properly laid in sound mortar or cement, will resist the effects of heat for a considerable time; stone, if laid as well in the middle as on the inner and outer surfaces, lasts a long time, unless it fails in the unsupported parts over the openings, which it always does when the lintels and the tops of the windows are made of the same material.

Openings for doors and windows in a stone wall, to be safe, should be mounted on the top with brick arches, which would carry the load without any difficulty long after stone in such a situation would have become calcined, and probably allowed the whole of the superstructure to fall down. For stairs, stone is a very dangerous material, unless it is embedded on some substance which can carry it when it gets hot. Stone stairs are usually made by tailing in the ends of a number of blocks of stone a few inches into a wall, leaving some 2 or 3 ft. protruding, and hanging unsupported in mid-air. After such stairs have been completed, they present an imposing appearance of solidity and strength, and so deceive the eye; but if fixed at a height of 30 or 40 ft., and even at the ordinary temperature of the atmosphere, the block would be somewhat fragile. There can be no doubt that any sudden rise of temperature, such, for instance, as might be produced by pouring a kettle of boiling water on it, would suffice to bring it to the ground. In this case, the exposed part would expand with the heat, the supported part, being protected, would not expand, and a fracture would occur between the two, generally close to the wall.

Such are some of the principal dangers of the use of stone, but of all building materials there is none which require more extreme care and delicate treatment than iron. Imagine a straight iron rod supported only at its ends, and capable, at the ordinary temperature of the atmosphere, of carrying a heavy weight in the middle. Let a strong fire be lighted under it: in a few moments the rod will lose its straightness, first sagging in the middle, then dropping altogether, next fusing, and finally running away; yet this is a material which many persons persist in calling fireproof, and put to carry loaded floors in buildings which they designate by the same improper epithet. The employment of these materials cannot be prohibited. Therefore greater reason exists for exposing their weakness in respect of withstanding fire, and pointing out necessary precautions in their use. Wherever iron is used it should be protected by terra-cotta, good brickwork, sound plastering, or, if nothing better can be found for the purpose, solid wood-work round it.

Wood-work, if really sound and solid, will resist for almost any length of time every possible effect of heat short of actual flame; even when flame has reached it, it is by no means destroyed at once, but, on the contrary, is sometimes found to last for hours; and wood protected on its under side by proper plastering, which will not fall down or crack on the application of heat, seems to be a roost powerful resister of flame. It is probably to the scamping now so common that we owe the diminishing use of timber as a material for the construction of buildings destined to carry heavy loads. In this country, ceilings are male to look solid enough, and, if they were only what they, represent themselves to be, they would in most cases be almost impervious to the effects of either heat or flame; but let them be pierced through, and they are found to be a sham, being a mere skin of plaster adhering to some thin strips of wood, which may be termed indifferently laths or firewood according to the taste of the observer.

These strips are tacked on to the lower parts of the joists, and the spaces between them and the flooring boards over the joists are simply so many flues, commonly containing only very foul Aid noxious air, but capable at any moment of being converted into most dangerous hidden passages for smoke and flame. Air-passages are also found in the lath-and-plaster partitions between rooms, behind the skirting boards of rooms, and under the steps and behind the skirting-boards of stairs. All sound building is more or less good building for resisting the effects of heat; and all scamping is dangerous.

The ' English Mechanic' observes that fire-proof partitions may be constructed on the principle adopted in France. The timber frames, braces, and quarterings are filled in with rough stone rubble, and the surfaces are lathed with strong oak laths, 2 in. or 3 in. wide, every 4 in. or 6 in. apart. A coat of plaster is then applied at the same time on each side, and pressed through; the mortar thus Alls up the spaces, and the rubble is rendered solid and compact. This plastering is put on thick enough to cover the timbers and laths, and to form a continuous and concreted body of material rather than a filling-in merely. Our bricknog partitions are somewhat similar, though the plastering on the latter is generally more superficial, and apt to peel off from the want of a proper key. Ceilings are sometimes formed in a similar way to the walls above described, the battens or laths being incorporated or imbedded in a body of plaster which is forced through them on a level platform fixed 2 in. or 3 in. from the laths. The joists and woodwork are thus completely immersed in a body of plaster or rubble, and are protected from fire. Staircases also are rendered unassailable by being filled in with concrete.