Читать книгу Description of the Process of Manufacturing Coal Gas - Friedrich Christian Accum - Страница 6

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The new art of lighting houses, streets and manufactories, with carburetted hydrogen, or coal gas, is one of those modern discoveries on which the admirers of science and the inhabitants of this country in particular, have greater reason to congratulate themselves, than any other invention or discovery of the present age.

This art is so wonderful and important, it speaks so forcibly by the effects it has already produced, that it cannot fail to increase the wealth of the nation by adding to the number of internal resources, as long as coal continues to be dug in this island from the bowels of the earth.

For if we distribute the catalogue of human wants which a civilized state of society has introduced, the production and supply of artificial light, holds next to food, clothing and fuel, the most important place. We might indeed exist without it, but how large a portion of our lives would in that state be condemned to a state little superior in efficacy to that of the animals around us.

If we could for a moment suppose the privation of artificial light, during the absence of the Sun, it would follow as an immediate consequence that the greatest part of the globe on which we dwell, would cease to be the habitation of man. Whether he could ensnare or overtake those animals upon whose unprepared remains he would then be compelled to feed; whether he might store the fruits of the earth for his winter supply—what might be the physical and moral consequences of a state of such desolation, may perhaps be conjectured, but no estimate can show its dreadful magnitude.

How much do our comforts, and how greatly does the extent of our power depend upon the production and supply of artificial light. The flame of a single candle animates a family, every one follows his occupation, and no dread is felt of the darkness of night. It might be a curious speculation to enquire how far, and in what respect, the morals of men would become degraded by the want of this contrivance. But it is sufficient on the present occasion, that, previous to entering upon a dissertation respecting a new art of procuring light, a train of ideas has slightly been hinted at, which cannot fail to show its magnitude and importance.

The progress of the new art of lighting houses, streets and public buildings, by means of the inflammable gas obtainable from coal, has been within these few years uncommonly rapid. The number of gas-lights already in use in the metropolis alone, amounts to upwards of fifty-one thousand. The total lengths of mains in the streets through which the gas is conveyed from the gas-light manufactories into the houses, now measures two hundred and eighty-eight miles.

The gas-light illumination has also spread far and wide through the country. Establishments for the supply of the new lights are carried on at Edinburgh, Glasgow, Liverpool, Bristol, Bath, Cheltenham, Birmingham, Leeds, Manchester, Exeter, Chester, Macclesfield, Preston, Kidderminster, and in many other towns and places of Great Britain.

Every body is now convinced that pitcoal is capable of furnishing light superior to that obtained from oil, wax, or tallow. The public attention is awakened to the new value of coal, and will not rest till the art of lighting with gas is pushed to the utmost of its extent.

In order to arrive at a full and accurate knowledge of the many advantages attending the application of carburetted hydrogen or coal gas, as a substitute for candles or lamps, it may be necessary, especially for the information of those readers who have never personally witnessed this mode of illumination, to take a brief preliminary view of some of the leading objects of public and private utility, to which this mode of procuring and distributing light may be applied, and of the extent to which it is entitled to national encouragement.

The chief advantages attending the use of gas, are superiority and uniformity of light, saving of labour, cleanliness, safety and cheapness.

It must be difficult for a person wholly unacquainted with this art, to imagine with what facility and neatness gas-lights are managed. The gas being collected in a reservoir, is conveyed by means of tubes, which branch out into smaller ramifications, until they terminate at the places where the lights are wanted. The extremities of the branching tubes are furnished with burners, having small apertures out of which the gas issues with a certain velocity corresponding to its degree of pressure. Near the termination of each tube, there is a stopcock, or valve, upon turning which when light is required, the gas instantly flows out in an equable stream. There is no noise at the opening of the valve, no disturbance in the transparency of the atmosphere; the gas instantly bursts on the approach of a lighted taper into a peculiarly brilliant, soft and beautiful flame; it requires no trimming or snuffing to keep the flame of an equal brightness. Like the light of the Sun itself, it only makes itself known by the benefit and pleasure it affords.

The gas flame is entirely free from smell. The gas itself has a disagreeable odour before it is burnt, and so has the vapour of wax, tallow and oil, as it comes from a candle or lamp newly blown out. This concession proves nothing against the flame of gas, which is perfectly inodorous.

The gas-light flame is perfectly steady; a benefit which persons accustomed to read or write by candle-light, are particularly capable of appreciating. With the other modes of illumination we have never the light of the same intensity for two minutes together, independent of that unpleasant dancing unsteady flame which is so harassing to the sight.

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. It is unnecessary to point out how valuable lights of this description are in nurseries, stables, warehouses, and chambers of the sick. From the facility with which the gas flame can be conveyed in almost any direction, from the diversified size and shape which it can be made to assume, there is no kind of light so well adapted for ornamental illumination.

The flame of coal gas is of a pure white colour, and of a body full and compact. In large masses, it becomes of the same flickering character which is common to all flames of large dimensions, and is owing to the agitation of the surrounding heated atmosphere.

The saving of labour connected with the employment of gas-light, may seem on a small scale to be trifling; but when it is considered that in large manufactories, it is not unusual to find several persons employed for no other purpose than trimming the lamps or setting and snuffing the candles of the establishment, the advantage gained on this head by the use of a species of light which require no sort of attention whatever, cannot but appear very considerable.

The cleanliness of the gas-lights is also a consideration of no small importance, they are attended with none of that spilling of oil, and dropping of grease, which makes the employment of oil-lamps and candles so injurious in many warehouses, shops and private dwellings.

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. While the ordinary oil lamps may be said merely to serve the purpose of making “darkness visible,” the gas-lights really dispel the dominion of night, and diffuse a body of light so wide-spreading and intense, as almost to rival the clearest moonshine.

The same brilliancy which makes the gas-lights of such utility out of doors, in lighting the streets, has been found of equal advantage in illuminating the interior of private dwellings, and large public buildings, such as churches, and theatres, &c. From a cluster of gas-lights, fewer by one-half than the number of oil lamps and candles required for lighting up a public edifice of this description in the most ordinary manner, a body of light is furnished which diffuses through the whole, a degree of mellow clearness which is not to be attained by the greatest number of oil lamps, or candles, which a due regard to respiration will admit of being employed. As examples of this, we have only to name the public theatres of the metropolis, all of which are lighted with gas, and in a manner which excites universal admiration.

It may perhaps be imagined that with a substance so inflammable, and amidst the blaze of resplendent flame which produces such beautiful effects, there is a peculiar risk of accidents by fire, but so far is this from being the case, that gas-lights are the safest of all lights. No danger can arise from these lights in any way, but what is common to candle lights and lamps of all kinds, and is the fault of none of them. The gas-lights are in fact a great deal less hazardous. There is no risk of those accidents which often happen from the guttering of candles, from sparks being detached, or from carelessly snuffing them. The gas-light lamps and burners, must necessarily be fixed to one place, and therefore cannot fall or otherwise become deranged, without being immediately extinguished. And further, at any time by shutting the main tube which conveys the gas to the burners and lamps, all the lights in the house can be immediately extinguished. In short, where gas is used, the master of the house, when he has turned the main stop-cock which conveys the gas into the collateral branch pipes, may retire to rest free from any of those apprehensions, which before harassed him, lest a candle might have been left burning, of lest the accidental dropping of a spark might become the cause of enveloping himself and family in destruction.

But the best proof of the great safety of the new lights is, that notwithstanding upwards of fifty-one thousand gas-lamps burn nightly in London, we have not heard of a single accident occasioned by them, though the lamps and burners are generally carelessly managed, while we have too often occasion to lament the effects arising from sparks of candles, or carelessness in snuffing them.

Hence the fire-insurance-offices engage to insure manufactories and public works, at a less premium, where gas is used, than when lighted by other means.

The excessive expence of insurance, arising from the numerous candles employed in most of the first-rate manufacturing establishments, and the combustible nature of the structure of the buildings; the great difficulty of retrieving the injury resulting to a well-organised business, from the accidental destruction of the machinery, are considerations alone sufficient to furnish the strongest economical, as well as political recommendations, for the adoption of the new lights in all manufactories where work is done by candle-light.

We have as yet only adverted to the application of gas in the more ordinary cases where light is wanted, but among other special purposes to which gas-lights may be applied, it would be improper to overlook the peculiarly advantageous use which may be made of them in the supplying of light-houses. From the splendour and distinguishing forms which the gas-light flame is capable of assuming, nothing can possibly be better calculated for such a purpose; and in point of economy, the employment of it would be attended with a saving of at least one half of the ordinary expence of oil lights. By means of a single furnace, as much gas may be produced in three hours, as will furnish during the longest winter night, a flame of greater brilliancy than is now furnished by any lighthouse in Britain, or indeed in the world. The body of flame may be increased to any size, merely by increasing the number of burners; and whatever may be the magnitude of the flame, it will continue to burn, without becoming in the least clouded by smoke, or the reflectors being in the least obscured. Should these considerations lead, as it is to be hoped they will, to the actual employment of gas in the lighthouses around the British islands, it will readily occur, that in proportion as the gas would be found attended with less expense than the present mode of lighting by oil, it would enable the commissioners for light-houses, out of the surplus means which would be thus placed at their disposal, to multiply the number of lighthouses, and thus to add most essentially to the security of British navigation. Nor is it in the case of maritime signal-lights alone, that the use of gas is applicable, by its superior efficacy and cheapness. The saving of expences to the country which would be effected by the substitution of coal gas, for oil and tallow in these and other public establishments, is a consideration which cannot be too much pressed on public attention. The annual expenditure for lighting the barracks of Great Britain alone, is said to fall little short of fifty thousand pounds; for less than one half of which sum, they might be lighted by means of gas much better, and a great deal more safely. Some idea may be formed from the practical saving in this department—how great might be the total saving, were this new mode of lighting adopted in all our national establishments.

In the case of the public arsenals, however, the saving from the employment of coal gas is a consideration of far inferior importance to the superior security attending it. On the preservation of the stores which they contain may depend in a time of war the whole chance of success against the enemy nor can any body who has lived in this country at such a time have forgot the feverish alarm with which the people have frequently seen this security endangered by accidents arising from the use of moveable lights. Were coal gas exclusively employed in such establishments, the fixed position which can be given to the burners, and the absence of all danger from sparks must give a degree of security to those places from fire, far beyond what they at present possess, even when superintended with the greatest possible caution and fidelity.

The same remark is equally applicable to the government offices, public libraries, museums, in short, to all public establishments where the national value of the articles preserved is such that no possible means of increasing their security from destruction should be neglected.

We have now to turn our attention to another general point of view in which the introduction of lighting by gas is not less an object of interest to the public; we allude to the application of gas as a means of heating as well as lighting. Mr. Maiben[1] was the first who directed the attention of the public to this subject; he ascertained that gas from coal gives nearly the same heat when put into combustion, which is yielded by a third part of the coal from which it is extracted. In other words, it has been found that a quantity of fuel giving a particular degree of heat, may be employed so as to produce at the same time another substance yielding nearly an equal degree of heat in a different and more manageable form; a form in which it can be preserved for any length of time, divided into any portions, distributed in any direction, consumed in an open fire-place, or in a stove concealed in any shape; a form in which the flame may issue equally well from iron or from stone-ware, be instantly lighted up and instantly extinguished, be made to burn as long or as short a time as may suit us, and in any degree of intensity between the most animating and brilliant blaze and its total extinction; be extinguished in one room, and the next moment lighted up in any other; in short such a form, that by one proper arrangement from the beginning, with the same portion of fuel, we may at any time have the command of a chearful fire, an adequate and comfortable warmth in any part of our dwelling to which we may have occasion to move, as manageable, and in this way as portable, as the taper by the touch of which it is kindled. To those who have been accustomed to see before them a solid mass of burning fuel, this gas flame may at first have the less satisfactory appearance of a fugitive blaze which we perceive nothing to support. But its uniformity and permanence will soon banish this impression, while it is attended with other advantages not inconsiderable with respect either to comfort or convenience. There are no coals to be carried in, no ashes to be carried out; there is no blowing, no sweeping of cinders, no dust, no interruption of servants; there is no excessive heat in one stage, no sudden damping at another: we have the choice of any temperature, and which we can regulate with the utmost ease. The fire itself is lively and pleasant to the eye: inclosed in transparencies it receives a degree of splendour not easily imagined. Numerous applications of gas, as a source of heat for airing rooms, and other purposes, have already been adopted. It is used in kitchens for keeping meat warm, and for boiling water; in store rooms, in picture galleries, in libraries, for maintaining them at an equal temperature. By copper-plate printers, it is used for warming their plates; and by jewellers and other artists, for soldering.