193 



FIRE-ARMS FIRE ENGINES. 



gen gas, which, when mixed with a certain propor- 

 tion of atmospheric air, and brought into contact 

 with burning bodies, explodes. 



The warm springs, the existence of extinct vol- 

 canoes, the effects of those still in activity, and the 

 fact that the temperature of the earth becomes 

 warmer the deeper we descend, have induced many 

 philosophers to adopt the idea of subterranean fires, 

 or of a central fire. According to the former hypo- 

 thesis, there are combustible materials, in a state of 

 ignition, in the bowels of the earth, which produce 

 the heat indispensable for the production of the 

 above-mentioned phenomena. The latter hypothesis 

 supposes that the globe was once in a state of 

 igneous fusion, that the surface lias gradually be- 

 come solid by cooling, and that the interior of the 

 earth is still liquid and hot, and may remain so for 

 ever, if the heat received from the sun is equal to 

 that which it lost by radiation. 



Among the meteors accompanied by luminous ap- 

 pearances are St Elmo's fire, (called also Elias'sfire, 

 Helen fire), and the bolides or fireballs. The former 

 consists of little flames, which are seen in storms on 

 the ends of masts, and all pointed and angular 

 bodies : these are well known to be entirely electri- 

 cal but sailors, at least those of the south of Europe, 

 consider two flames, which they call Castor and Pol- 

 lux, a good omen, and a single one a bad omen. 

 The boudes are globes of fire moving with extreme 

 rapidity and great brilliancy through the air ; they 

 are sometimes attended by a rumbling noise, like 

 that of a loaded wagon ; this is often followed by 

 a violent explosion, accompanied with a fall of stones, 

 more or less abundant, the origin of which is as yet 

 dubious. 



FIRE-ARMS. Under this designation are com- 

 prised all sorts of guns, fowling-pieces, blunderbusses, 

 pistols, &c., which effect their discharge by the com- 

 bustion of gunpowder. The manufacture of these 

 weapons in England is extensive, employing at all 

 times, but especially during war, a large number of 

 persons. In consequence of the frequent accidents 

 from the bursting of insufficient barrels, the legisla- 

 ture of Great Britain has very properly interfered, 

 not to regulate their manufacture, but to prevent all 

 persons from using or selling barrels that have not been 

 regularly proved in a public proof-house. The first 

 act for this purpose was passed in 1813 ; but it was 

 soon after superseded by a fuller and more complete 

 one, the 55 Geo. III. c. 59. This statute imposes a 

 fine of twenty pounds on any person using, in any of 

 the progressive stages of its manufacture, any barrel, 

 not duly proved ; on any person delivering the same, 

 except through a proof-house; and on any person 

 receiving, for the purpose of making guns, &c., any 

 barrels which have not passed through a proof-house. 

 These penalties to be levied on conviction before 

 two justices ; with like penalties, to be similarly 

 levied, on persons counterfeiting the proof-marks. 

 For the manufacture of fire-arms, &c., see Iron 

 Manufactures. 



FIRE-BALLS ; 1. in natural philosophy, globular 

 masses of fire, of different magnitudes, moving through 

 the atmosphere with greater or less velocity, often 

 with burning tails, when they are catted fiery serpents. 

 Small balls of this sort are called shooting stars. There 

 are various conjectures in regard to the nature of 

 these phenomena. Chladni considers them to be 

 solid masses, formed above the region of our atmo- 

 sphere, and classes them with aerolites or meteoric 

 stones, (q. v.) 2. In gunnery, every ball which is 

 capable of being ignited and burned. In military 

 operations, such balls are thrown by night from 

 mortars or howitzers towards quarters which it is 

 desirable to examine. 



FIRE-DAMP. See Damps. 



FIRE-DRESS ; a new invention of the chevalier 

 Aldini, which is stated to be an effectual protection 

 against fire, in the reports of committees of the 

 highest respectability appointed to examine it at 

 Paris. It enables the wearer (as has been demon- 

 strated by public experiments) to approach with im- 

 punity, or even to pass through a fierce flame, to 

 rescue lives or portable valuable property, or to use 

 means for the extinction of fire. It consists of an 

 exterior light armour of metallic gauze, which fabric 

 was discovered by Sir Humphrey Davy to be imper- 

 vious to flame (see Damps'), and of an inner covering 

 of a material which is a slow conductor of heat. 

 Amongst flexible fibrous substances capable of being 

 spun and woven into tissues, the asbestos possesses 

 pre-eminently the property of slowly conducting 

 heat ; but the other fibrous matters in common use 

 for the purposes of clothing, such as wool, cotton, 

 &c., may, by immersion in certain saline solutions, 

 be rendered very imperfect conductors, so as to fit 

 them very sufficiently for preventing the transmission 

 of injurious heat to the body, during a temporary ex- 

 posure of some minutes to the action of flame on the 

 outward covering of wire gauze. See the London 

 Register of Arts for June, 1830. 



FIRE ENGINES are a species of forcing pumps, 

 in which the water is subjected to pressure suffi- 

 ciently strong to raise it to the required height. (See 

 Pump.) But, in order to remedy the intermission of 

 the jets of the simple forcing pump, and produce the 

 discharge of a continuous stream, a vessel, filled with 

 air, is attached to the engine. The water is forced 

 into this vessel by two forcing pumps, and the air 

 therein contained being condensed, reacts on the water 

 with a power proportioned to the condensation. The 

 spouting-pipe for directing the water upon the fire 

 proceeds from the common air vessel. The handles 

 are so disposed, that, while the piston of the one 

 pump is up, that of the other is down ; and they are 

 elongated for the purpose of enabling a great num- 

 ber of men to work them at the same time, so that 

 they may throw a large quantity of water. In New 

 sham's engines, two cylinders, constructed like 

 forcing pumps, are worked by the reciprocating 

 motions of transverse levers, to which the handles 

 are attached. In this way the water is forced into 

 the air vessel, from which it afterwards spouts through 

 a movable pipe. The accompanying engraving is a 

 perspective representation of Newsham's fire engine. 



It consists of a cistern A B, about three times as 

 long as it is broad, made of thick oaken planks, the 

 joints of which are lined with sheet copper. It is 

 moved by means of a pole and cross-bar, C, at the 

 fore part of the engine, which is so contrived as to 

 slip back under the cover of the cistern, and on four 



