Limeburner

“ In a sitting-room lighted thus with gas, we are obliged, in order to read comfortably by the distant source of light, to burn so much gas that the atmosphere of the room is seriously polluted by the products of this extravagant combustion. A lamp at a moderate distance—say eighteen inches or two feet, or thereabouts—will enable us to read or work with one-tenth to one-twentieth the amount of combustion, and therefore with so much less vitiation of the atmosphere, and, if we use a paraffin lamp, at much less expense. ”

“ The light emitted by incandescent lime (Drummond light, HYDRO-OXYGEN LIGHT, LIME LIGHT, OXYHYDROGEN LIGHT) is intensely brilliant, and is often made use of to enable workmen to continue operations at night. It is obtained by directing the flame produced by the combustion of a mixture of hydrogen (or coal-gas) and oxygen upon a small cylinder of lime. In the improved form of this light the lime is protected from crumbling by a cage of platinum wire, and is caused to rotate slowly by means of clockwork, so as constantly to expose a fresh surface to the flame. ”

“ On the contrary, when the flame is sounding, that is to say, when the necessary vibrations for the production of sound are produced in the tube, its form is narrow, and large at the top. While the air of the tube vibrates, the flame is very steady. The carbon in a great measure is eliminated as if by some mechanical process.
"Sounding-flames proceeding from lighting gas are in effect enveloped in a photosphere which does not exist when the flame is merely luminous. In the latter case the carbon is burnt within the flame, and contributes in a great degree to its illuminating power. ”

“ The one simple principle on which a lamp, whether a safety-lamp or any other, may be made to yield the full light due to the perfect combustion of the carbon of its aliment, is one long known to the miner as applied to ventilation. A single shaft will not ventilate a mine. In the same way, if a lamp or a candle be surrounded by a glass shade only open at the top, it will not burn properly. The taller the glass chimney the redder and dimmer will be the flame, until it is actually extinguished by the product of its own combustion. ”

“ It was natural, therefore, that men of science should, with a view to improvement, first direct their attention to the lamp. The pioneer in this course of inquiry was Argand, who, about 1748, contrived to secure “a double current of air;” which consists, as any one may see in the first lamp he meets with, of a wick, shaped like a hollow cylinder, enclosed in a glass tube. The heat caused by the combustion of the oil produces a vigorous draught, which leads to an abundant circulation of air both internally and externally; and air is for the lamp, as for man, the plant, and the animal—life! ”

“ First, where we illuminate a room with candles or oil we are contented with a less intense and more local light than when we are using gas, and in a room of ordinary size would be more likely to use a lamp or two candles than the far higher illumination we should demand if gas were employed. Secondly, the amount of water vapour given off during the combustion of gas is greater than in the case of the other illuminants, and water vapour absorbing radiant heat from the burning gas becomes heated, and, diffusing itself about the room, causes great oppression. ”

“ Whether the exchange of electricity is produced on a vast stretch between two rows of clouds, or whether it is manifested by a long thin spark launched like an arrow and veiled by the curtain of clouds, all that can be seen is a strange light, vague, diaphanous, instantaneous, which sometimes spreads itself like a sheet of fire all over the horizon.
It is diffused lightning which gives us the finest storm effects on those heavy summer evenings when the air is breathless and saturated with electricity. ”

“ As scientific knowledge increased, efforts were made to get solid matter into the flames of light-sources. Instead of confining efforts to the carbon content of the gas, solid materials were actually placed in the flame, and in this manner various incandescent burners were developed. A piece of lime placed in a hydrogen flame or that of a Bunsen burner is seen to become hot and to glow brilliantly. By producing a hotter flame by means of the blowpipe, in which hydrogen and oxygen are consumed, the piece of lime was raised to a higher temperature and a more intense light was obtained. ”

“ The oil placed in the lamp reservoir is drawn up by the capillarity of the wick to the flame, and being there volatilized, is converted by the heat of the burning flame into a gaseous mixture of hydrogen and hydrocarbons, which is ultimately consumed by the oxygen of the air and converted into carbon dioxide and water vapour, the products of complete combustion.
To secure high illuminating power, together with a smokeless flame and only products of complete combustion, strict attention must be paid to several important factors. ”

“ The flame of a gas-light compared in point of brilliancy to that of a candle, is as the flame of a common oil lamp, compared to the flame of a lamp of Argand. The difference between a street, on the night of a general illumination, and any other night when the street is under the dull glimmering light of the ordinary oil lamps, is scarcely more remarkable, than the difference between a street lighted by gas, and one lighted by oil. ”

“ The fire that cooks our food gives off a quantity of useless light-waves; the oil-lamp that brightens one’s rooms gives off a quantity of useless, often obnoxious, heat.
The ideal illuminant and the ideal heating agent must be one in which the required waves are in a great majority. Unfortunately, even with our most [Pg 343] perfected methods, the production of light is accompanied by the exertion of a disproportionate amount of wasted energy. In the ordinary incandescent lamp, to take an instance, only 5 or 6 per cent. of the energy put into it as electricity results in light. ”

“ From the splendour and distinguishing forms which the gas-light flame is capable of assuming, no light is better calculated for signal-lights than this. By means of one single furnace as much gas might readily be procured as would furnish a flame of sufficient intensity, during the longest winter night, exceeding in brilliancy or intensity of light any light-house in Britain or elsewhere. ”

“ At such a temperature the proportion of luminous rays to the total heat produced in combustion would be more than doubled, and the brilliancy of the light would at the same time be greatly increased. Thus improved, gas-lighting may continue its rivalry with electric lighting both as regards economy and brilliancy, and such rivalry must necessarily result in great public advantage. ”

“ In the case of a well-trimmed Argand oil-lamp, or an Argand burner for gas, the flame is in general most intensely hot, and the light is of a clear white character.
The third point which demands attention is the amount of heat transmitted from the flame to the eyes. It often happens that people, in order to economize light, bring the lamp quite close to the face. This is a very bad habit. The heat is more injurious than the light. Better burn a larger flame, and keep it at a greater distance. ”

“ As this roaring flame contains a great quantity of carburetted hydrogen, and even of vapour of oil, escaped from combustion, it possesses a disoxidizing or reducing property in a very high degree.
PLACES FIT TO WORK IN.
Every place is adapted for a workshop, provided it is not too light and the air is tranquil. The light of the lamp enables one to work with more safety than day-light, which does not permit the dull-red colour of hot glass to be seen. Currents of cold air are to be avoided, because they occasion the fracture of glass exposed to them on coming out of the flame. ”

“ The illuminating power and the calorific value of air-gas, unless the manufacture is very precisely controlled, are apt to be variable, and the amount of light, emitted, either in self-luminous or in incandescent burners, is somewhat indeterminate. ”

“ The production of fire also, of course, entailed the creation of light, which in its developments has been of an importance second only to the improved methods of heating. So accustomed are we to our candles, our lamps, our gas-jets, our electric lights, that it is hard for us to imagine what an immense effect their sudden and complete removal would have on our existence. At times, when floods, explosions, or other accidents cause a temporary stoppage of the gas or current supply, a town may for a time be plunged into darkness ”

“ The flame of a common lamp he proved, by a very simple experiment, to exceed even the white heat of solid bodies, and which is easily shown by the simple fact of heating a piece of platinum wire over the chimney of an Argand lamp fed with spirit of wine; when it will be seen that air, which is not of sufficient temperature to appear luminous, is still sufficiently hot to impart a white heat to a solid body immersed in it. ”

“ It is not to the flame, as such, that we are to ascribe these effects. Effects substantially similar are produced when we employ jets of unignited coal-gas, carbonic acid, hydrogen, or air. These jets may be rendered visible by smoke, and the smoke jets show a sensitiveness to sonorous vibrations even greater than that of the flames.
When a brilliant sensitive flame illuminates an otherwise dark room, in which a suitable bell is caused to strike, a series of periodic quenchings of the light by the sound occurs. Every stroke of the bell is accompanied by a momentary darkening of the room. ”

“ So that the regenerative forms of burner, by giving the greatest illuminating power per cubic foot of gas consumed, yield a smaller amount of vitiation to the air per candle of light emitted.
An ordinary room, say 16' X 12' X 10', would not be considered properly illuminated unless the light were at least equal to 32 candle power; and in the table below the amount of the oxygen used up and the products of combustion formed by each class of illuminant and burner in attaining this result are given, the number of adults who would exhale the same amount during respiration being also stated. ”

“ Among the best-known makes of lamps there is one with a powerful burner which gives a clear, steady flame, equal to two or three ordinary gas-jets. The only draw-back connected with it is the intense heat it radiates, which makes it objectionable in summer. ”

“ The Fire of Incandescent Lamps.—An active incandescent lamp may be broken in the midst of cool combustibles, even of gun-cotton, without setting them on fire, so rapid is the destruction of the carbon filaments in the open air. But a long continuance of the lamp in immediate contact with a combustible envelope may determine ignition, the more readily the more slowly heat and air pass through the envelope. Thus gummed cotton or other goods will take fire more rapidly than similar goods ungummed or loose. ”

“ A lamp is an apparatus for converting hydro-carbon mineral oil into gas and burning it efficiently. The gas-jet burns gases produced by driving off hydro-carbon vapours from coal in apparatus specially designed for the purpose. Gas-making is now, in spite of the competition of electric lighting, so important an industry that we shall do well to glance at the processes which it includes. ”

“ In the month of July, 1885, on the day following a violent thunderstorm which had struck the telegraph-office in the station of Savigny-sur-Orge, I myself picked up a little black powder off the telegraph poles, which had been left by the lightning, and which had a sulphurous smell.
The production of this ponderable matter has often been attributed to bolides, but direct observation proves beyond a doubt that the electricity carries various solid substances found on earth after a storm.
Lightning is truly the most venerable of glass-makers. ”

“ Adopting the convention, however, an incandescent burner is one in which the fuel burns with a non-luminous or atmospheric flame, the light being produced by causing that flame to play upon some extraneous refractory body having the property of emitting much light when it is raised to a sufficiently high temperature; while a luminous burner is one in which the fuel is allowed to combine with atmospheric oxygen in such a way that one or more of the constituents in the gas evolves light as it suffers combustion. ”

“ One thing is certain, at any rate, and that is, that in augmenting the potential and frequency we rapidly intensify the streams; and, though it may be very sanguine, it is surely not altogether hopeless to expect that we may succeed in producing a practical illuminant on these lines. We would then be simply using burners or flames, in which there would be no chemical process, no consumption of material, but merely a transfer of energy, and which would, in all probability, emit more light and less heat than ordinary flames. ”

“ See Lamp of Davy, Safety Lamp, and Ventilation.
The state of the air in coal mines, from very early periods till the discovery of the safe-lamp, was judged of by the appearances exhibited by the flame of a candle; and this test must in many circumstances be still had recourse to. When there is merely a defect of atmospheric oxygen, the air being also partially vitiated by a little carbonic acid, either from choke-damp or the lungs and candles of the miners, the lights burn with a very dull flame, the tallow ceases to melt in the cup formed round the wick, till the flame flickers and expires. ”