Gas flame

“ The size, form and intensity of the gas flame, are regulated by simply turning the stop-cock which admits the gas to the burner or lamp. The flame may at command be made to burn with an intensity sufficient to illuminate every corner of a room, or so low and dim, as barely to be perceived. ”

“ But besides the flame, which is a peculiar gas in the state of combustion, heat expels from coal an aqueous vapour, loaded with several kinds of ammoniacal salts, a thick viscid fluid resembling tar, and some gases that are not of a combustible nature. The consequence of which is, that the flame of a coal-fire is continually wavering and changing, both in shape, as well as brilliance and in colour, so that what one moment gave a beautiful bright light, in the next, perhaps, is obscured by a stream of thick smoke. ”

“ The gasoline and alcohol flames have their drawbacks, one of which is the starting of the burner and the waiting for the heat. They are also unhandy in directing the flame on parts of the work. As I desired a burner for quick work and one whose flame I could direct at any angle, for repoussé and chasing on copper and silversmith's work, I made the one shown in the sketch to attach to a hose and connected it with the gas pipe of the illuminating system in the house. ”

“ Coloured flame may be produced by various other substances, many of which are expensive, and therefore could not be employed economically. Thus, in fire-works made with hydrogen gas, or inflammable air, which have a pleasing effect, by forcing the gas, either from a bladder, oiled-silk bag, or gas-holder, through a variety of revolving jets, which are so arranged as to exhibit stars, or through pipes furnished with small apertures, &c. ”

“ Either they act through the expansion of a solid, or through that of a liquid. They are so adjusted, that, at a certain temperature, the expansion of the material chosen causes the gas supply to be nearly completely cut off. The gas flame is prevented from being wholly extinguished by means of a small by-pass. ”

“ Fire-damp, marsh-gas, or carburetted hydrogen, is colorless, almost scentless; it burns with a blue flame, and makes respiration impossible. The miner could not live in a place filled with this injurious gas, any more than one could live in a gasometer full of common gas. Moreover, fire-damp, as well as the latter, a mixture of inflammable gases, forms a detonating mixture as soon as the air unites with it in a proportion of eight, and perhaps even five to the hundred. When this mixture is lighted by any cause, there is an explosion, almost always followed by a frightful catastrophe. ”

“ By applying a blast of air at the ordinary gas jets, and supplying the gas by a separate pipe, or series of pipes, below the open end of the burner, this can be converted into a furnace of extraordinary power. It is quite possible to burn as much as 2,000 cubic feet of gas per hour per square foot of burner surface, producing a heat sufficient to fuse any ordinary crucible. You see its power when I place a bundle of iron wire in the flame; it is, in fact, a concentration of hundreds or thousands of powerful blowpipe flames in one mass. ”

“ If the gas be copious, the flame elongates into a sharp spire, as well as the top. It is in general reckoned dangerous when the tip changes from the bluish-gray to a fine blue colour, accompanied with minute luminous points, which pass rapidly upwards through the flame and top. When the symptoms are manifestly dangerous, a sudden movement of the hands or body is liable to produce ignition by agitation of the fire-damp. ”

“ When the supply of air is sufficient for the immediate and complete combustion of the whole of the combustible matter, no such precipitation takes place, and the flame is neither white nor brilliant. The richest coal-gas, mixed with sufficient air to convert all its hydrogen and carbon into water and carbonic acid, explodes with a pale blue flash; yet the same gas, when consumed in the ordinary way, burns with a rich white flame. Every one must have noticed the effect of a gust of wind upon the flaring gas-jets of a butcher’s shop ”

“ Phosphorus wrapped in paper, and struck with a hammer on an anvil, will likewise enflame.
THE DANCING FLAME.
Make a very small gas jet, to which fit a minute burner; Sugg’s steatite pinhole burner answers best. Above the burner, at a distance of two inches, fix a seven-inch square piece of wire gauze; ordinary window-blind gauze of thirty-two meshes to the lineal inch acts perfectly. Turn the gas on, and light the flame above the gauze. Keep the room free from draught, and the flame will be steady; but at the least sound the flame is certain to move. ”

“ In relation to the production of flame, we may observe, that, as sundry solid and fluid substances are inflammable, the products of combustion depend on the composition of the substance made use of, and the condition under which it is burnt. As to gaseous substances that are inflammable, the base of some gases, we may remark, as carbon and hydro [6] gen, unite in the process of combustion with the base of other gases, (as oxygen;) and in other instances, the gas itself takes fire, and exhibits the phenomena of flame. Now carbonic acid gas extinguishes flame, although its base is inflammable ”

“ Always have a large blanket at hand to smother flames in burning clothing—also a bucket of water and a quantity of sand. A siphon of carbonic water is an excellent fire extinguisher.
The gas of gasoline is heavier than air, so a container should never be held ABOVE a flame. Keep kerosene and gasoline containers well corked and at a distance from fire.
Never inhale breath while performing with fire. FLAME DRAWN INTO THE LUNGS IS FATAL TO LIFE.
So much for the entertaining side of the art. ”

“ When the fire-damp comes off suddenly in any case, rendering the air foul and explosive at the foreheads, if no other remedy be found effectual, the working of the coal must be suspended, and a current of air sent directly from the fresh in-going stream, in order to dilute the explosive mixture, before it reaches the furnace. This is termed skailing the air; for otherwise the gas would kindle at the furnace, and flame backwards, like a train of gunpowder, through all the windings of the work, carrying devastation and death in its track. ”

“ A burst of flame within the gas-bag would not set the gas on fire, because there would be no air inside to feed the fire, but surrounding the gas-bag there was always a certain leakage of hydrogen which would mix with the air in the compartment and this would produce an explosive mixture which needed but the touch of fire to set it off. ”

“ When hydrocarbons form a part of the combustible gas, as they do in nearly all illuminating gases and oils, some carbon is usually set free in the process of combustion. This is made very hot by the flame and becomes incandescent, giving out light. In a well-regulated flame it is afterward burned up, but when the supply of oxygen is insufficient it escapes from the flame as lampblack or soot. That it is temporarily present in a well-burning luminous flame may be demonstrated by holding a cold object, such as a small evaporating dish, in the flame for a few seconds. ”

“ Soot therefore always indicates an imperfect combustion. Hence [9] flame is produced from those inflammable substances only, which are either totally volatile when heat is applied to them, so as not to alter their chemical habitudes—or which contain a quantity of combustible matter that is readily volatilized into vapour by heat, or the elements necessary for producing such vapour or gazeous products, when the chemical constitution of the body is altered by an increase of temperature. ”

“ Thus, phosphorus at 150°, and sulphur at 550°, are said to take fire, and two acid products are formed; at 800°, hydrogen gas explodes with oxygen, and produces water; and, according to Ure's view, the flame of combustible bodies may in all cases be considered as the combustion of an explosive mixture of inflammable gas, or vapour, with air; and as to the change of quiescent into distributable heat, and the causes that modify combustion and flame, the facts on these heads are numerous and very important. ”

“ There is no strict scientific definition of flame, but for the purpose of this article it will be regarded as a name for gas which is temporarily luminous in consequence of chemical action. It is well known that the luminosity of gases can be induced by the electrical discharge, and with rapidly alternating high-tension discharges in air an oxygen-nitrogen flame is produced which is long and flickering, can be blown out, yields nitrogen peroxide, and is in fact indistinguishable from an ordinary flame except by its electrical mode of maintenance. ”

“ In every case I have seen, without one single exception, the holes are either too small, or the burner is placed too close, and the consequence is that the gas, instead of burning inside the holes, as it should, passes through partially unburnt, and is consumed at the opposite end, where it is absolutely useless, the flame not being in contact with or under the surface to be heated, and therefore doing no work. ”

“ The chief danger with an apparatus of this sort is its liability to accident by the careless use of the gas, and, as a mixture of hydrogen and air is very explosive, great care must be taken to exhaust all the air in the generator and tubes before attempting to light the gas at the blow pipe. The only way to make sure that the air is exhausted is to test the gas, as described under the head of “The Flame and Its Management.” ”

“ In all the gas-light burners, constructed on Argand’s plan, care should be taken that the flame be in contact with the air on all sides, and that the current of air be directed towards the upper extremity of the flame. ”

“ The flame produced from coal, wood, turf, oil, wax, tallow, or other bodies, which are composed of carbon, hydrogen and oxigen, proceeds from the production of carburetted hydrogen gas, evolved from the combustible body when in an ignited state.
It must have been noticed at the same time, that in the common mode of burning coal in a fire-place, or stove, nearly the whole of this inflammable gaseous matter is lost. We often see a flame suddenly burst from the densest smoke, and as suddenly disappear ”

“ Here we have oil and cotton, two [Pg 347] things which would speedily set a warehouse in flames from top to bottom, but we cannot even ignite them, try all we can. Why?—Because we must first obtain a gas, oil will not burn liquid; it must be heated to a gaseous point before it will burn, as all combustion depends upon that,—so flames mount high in air. Now in a candle-flame, as will be seen in the diagram (fig. 331.) , there are three portions,—the inner dark core, which consists of unburnt gas; the outer flame, which gives light; and the outside rim of perfect combustion non-luminous. ”

“ But there are other circumstances connected with the combustion of candles and lamps, which I cannot explain to you till you are acquainted with carbon, which is one of their constituent parts. In general, however, whenever you see flame, you may infer that it is owing to the formation and burning of hydrogen gas*; for flame is the peculiar mode of burning hydrogen gas, which, with only one or two apparent exceptions, does not belong to any other combustible. ”

“ It was also up to the officers to explain to their men as much as they themselves had learned about gas clouds, and to impress on them, for example, that by moving to the rear they would move with the gas, and that if they got flurried they would breathe more deeply and would run much more risk of being gassed. ”

“ A flame may be cooled in another way than by means of some cold body held in it, namely, by mixing some indifferent gas with the combustible gas. If, instead of air, a stream of carbonic-acid gas be admitted at the bottom of a Bunsen lamp, the flame becomes "non-luminous." We get the same amount of heat in the flame as before, since we burn the same amount of gas; but this heat has not only to be applied to heating the illuminating gas and the products of its combustion, but has also to heat the carbonic-acid gas. ”

“ A common fault is that there is too much gas allowed to flow through the nipple, compared with the amount of air being drawn in at the air aperture, fig. 13. The result is, we get a flame of great length, but one which is not at all suited to our requirements; and instead of giving up its heat to the tube and the asbestos lining of the chimney, a large amount of gas we are presumably burning in the chimney is not being burnt there at all, for, on applying a light just above the chimney top, a quantity of this gas we are wasting will be seen to burn with a flickering blue flame. ”

“ Q. Why will not cinders blaze, as well as fresh coals?
A. The flame of coals is made chiefly by hydrogen gas. As soon as this gas is consumed, the hot cinders produce only an invisible gas, called carbonic acid.
Q. Where does the hydrogen gas of a fire come from?
A. The fuel is decomposed (by combustion) into its simple elements, carbon and hydrogen gas. (see p. 33)
Q. Why does not a fire blaze on a frosty night, so long as it does upon another night?
A. The air (being very cold) rushes to the fire so rapidly, that the coals burn out faster, and the inflammable gas is sooner consumed. ”

“ Mention has already been made of the slight noise caused by the explosion of the gas shell, and instructions were accordingly [143] issued that all shell that sounded like duds were to be regarded as gas shell, and the respirators adjusted accordingly. This got over one of the elements of surprise.
A great many men, especially those in battery positions, had been gassed in their dugouts before warning of the gas bombardment had been spread. Numbers of these men were actually gassed in their sleep and were awakened too late by the choking fumes themselves. ”