GAS-LIGHT.

New Zealand Herald, Volume II, Issue 444, 15 April 1865, Page 5

GAS-LIGHT.

A VETERAN —a mm of tlie past generation now fast dying out—ono who can carry back his romiuiscenco s as far »3 the beginning of tlio century —who can cut ] to mind tlie rejoicings for the victory of tho Nile, or the wail that went up from the nation's heart on tho news of its hero's death at Trafalgar,—will bo ablo to bring before his mind's eye a vivid picture of tho scene which London and tho other largo English cities presented in those days—or rather nights; when " llie distant lantern shed its oily ray" across the sombre and deserted streets, where " Mohocks reigned supreme and bloods kicked up a row." He who was a hubiliii'■ of Paris and important- Continental towns down to a much later period, will have before liim a still gloomier recollection of tho old rererbere slung across the middle of the street, the rope of which was much more useful for purposes of suspension than the lamp for the light which it emitted. Younger men than these, who have been "long in populous cities pent"—it they have remained in Europe —can form no idea of what a large city is at night, unliglited by any thing more brilliant than the antiquated arrangements of oil-lamps or mutton dips. We .Antipodenns, however, have hitherto had ample opportunities of knowing all about the inconveniences of dwelling in " outer darkness." The few apologies lor lamps, sparsely scattered through some of the mtre important thoroughfares of Auckland, giving out a just sufficient glimmer to prevent the belated wayfarer from sunning his nose against the ugly posts that supported them. Hut at long and last, we are about to emerge from this siato of Cimmerian gloom —the presence of gas in Auckland is an accomplished fact, and this evening we are promised the first exhibition of its powers of enlightenment. It is true that this display must not be anticipatrd to be a very brilliant one, the arrangements both at tho works and in the streets being still far from complete; but the Liirectors of the Company, yielding to the impatience of the public to see the new- mode of illumination actually in opeiation, before the dark nights of winter set in, have urged on the work much faster than it was at first thought possible to accomplish it. and by the indefatigable exertions of the Knginetr, a supply has been obtained, sufficient at least- to give an idea of the aspect our streets will present when the whole system is in action. As the subject will be an interesting one to many who have but a very imperfect acquaintance with the process of gas-making, we puipose devoting some space to a minute account of its details, as carried on at tho Company's works in Brickfield Bay, premised by a short history of its discovery.

That curious people the Chinese, who sot 111 to have found out everything, before anybody else was born, and then to have forgotten it, are said to hare known (lie economical uses of gas 3000 years ago, a? thoy have been in the habit of evaporating salt brine, and lighting houses by its aid at a spot 30 miles from Pelnn, where a natural stream of it flows from the ground, such as occurs in many other parts of the world, where it is applied to similar purposes—notably in Armenia, Transylvania, and America. A large jet of thi* sort was tapped in rutting a deep trench acioss Chat Moss, in Lancashire, in 1851, which being lighted burned for a long time with A iierce ilame of eight feet in length. The first philosopher who experimented upon the artificial production of this iluid seems to have been tho Tiev. John Clayton, who, in IGSS, succeeded in distilling what he calls the " spirit" fiom coal, and confining itin bladders, which helighted for theamusementof hiß friends, but Mr. Murdoch of Redruth in Cornwall was the first to turn the discovery to practical account, and the fir.=t public display of his invention was made at Soiio, niiir Birmingham, at tho illuminations for the Peace of ISO 2. Mr. Winsor, a German, took up the idea with such enthusiasm that he was pronounced to bu insane, and his scheme for lighting London with the new " inflammable air" denounced as visionary and dangerous in the extreme. lie, however,lighted the Lyceum Theatre in 1803, and tho use of gas made its way slowly but surel}' till 1813, when "Westminster bridge was first lighted with it. From this time forth its progress lias been so rapid that its employment, wherever it is procurable, may now be almost said to bo universal. It lias even reached Constanti ople, and its effect in brightening up the sleepy Turks is said to be marvellous. It was a long time, however, in making its way into privatj houses, partly from an unfounded dread of some occult danger supposed to attend it, and partly trom the annoyance experienced from the imperfect fittings. These prejudices have been greatly removed by a better understanding of its real nature, and improved arrangements of fitting 3 and burners; so that in Glasgow (which is said to be the most " gassy" city in tho world), thero is scarcely a house, or even an apartment, without its ' jjaselier.' As -an examplo of th.; enormous consumption now going on, it is stated that the Westminster Gas Company has sent out five million cubic feet in one night of mid-winter. Coire we now from these statistics of gigantic enterprise to our own comparatively diminutive but equally useful establishment on the shores of the Waitemata.

Most of our readers are by this time acquainted with the locality of the Gas Works. To those who are not, it may be sufficient to say that thoy are situated in a small bay on the west of the city, where a considerable s;a=e has bean eocured, partly by cutting down and levelling the high precipitous clilfs that there form the sea boundary, and partly by reclaiming a portion of the river, which ia cmbanke I with a substantial wall of scoria masonry. On descending a steep road out of Hobson-scrcet, and passing through a pair of gates, wo come to the Retort House, an open shed of iron 50 feet by GO, arid 2-"i feet high, supported by iron columns. Running alone the centre of this is a sort of wall of massive brick-work, with a short temporary chimney shaft at one end. In this are inserted six sets (or " beds," as they aro technically termed) of retorts, arranged in groups of five each, three oval and two round. Below these ore furnaces which aro all connected with tho temporary chimney at present, but will ultimately connect with the large central sbaft, which will bo ninety feet high, but the completion of which has been suspended for want of the required kind of bricks. A retort, it may bo explained, is a vessel of iron or fire-clay in which the coal is distilled into gas, tar, and its various other components, by means of tho heat derived from the furnace beneath. It is of a more or less cylindrical shape, and has a door at its mouth, which canbe closedby means of aluting ofclay and lime and is then Ecrewed up firmly by means ofa double lever until it is perfectly air-tight. These retorts are of clay, which is considered preferabl to iron top many practical reasons, and each contains a charge of about sixty pounds of coal. This being put in and the mouth closed, it is allowed to remain from four to six hours • exposed to the intense heat of tho furnace, when the door ia opened and the charge withdrawn in the shape of almost white-hot cinders, or " coko." It has then parted with nearly all its constituents except a nearly pure carbon. These have escaped in the shape of a thick smoky gas, up a pipe which ascends from the top of the retort and dips i;ito an IS-inch tube, running the whole length of the building, and called the hydraulic main. In this main, and iu the condensers to which it is then admitted, and where it is obligedto pass ovor water up and down a series of bent pipes, the gas by cooling and the force of gravitation deposits the greater portio i cf the tar and ammoniacal liquor vhich came otm with it.

I leso find their way thievgh nipes to n tank five I feet sqv are, filled with water, win-re they are stored, cither for sale or tor use, in tl o fuim.ei s, as convenience may dictate. We undi rstund a steioki eper in Auckland has already ag)eeel with the Cemjany to tale all it can produce of this article, so indispensable to a maritime community. Beyond the retort-house is a horizontal feur-horsr steam-enpine, tho chief otlice of which is to draw over the gas faster than it would flow naturally, so as to lessen the too great pressure in tho retort, which would have a tendency to forco it through the pores of tho vessel itself. The fluid is thence conducted into a tall iron cylinder, know n as tho " scrubber," where it is cleansed from its carbonic acid and other deleterious ingrc. dicnts, by being iorccd through tho interstices of several luyeis of broken brick, which arc spiead on open iion giatings or trays, constantly exposed to tho spray front a jot of water. lln nee it passes to the " purifier," an ircn box of eight feet square, with a teciircd by what, is called a "water-lute," where about forty bußhcl of lime are spread oyer similar gratings slightly moistened with water. Here the gas gets rid of its carbonic acid and sulphuretted hydrogen, and being now puro is admitted in to the gas-holder, where it is stored till wanted. The gas-holder is a boiler-plate cylinder of 5 0 feet diameter and 10 feet iu height with an open bottom and a Eliglitly domed top. 'J his is built up, it; situ, like a house, and strengthened internally with &11 sorts of joists and tic-rodß. When empty (not when tilled with uchr, as oddly described by a contemporary) this stands upon the bottom of a circular briek tank, 5-1 feet iu diameter, into which a quantity of water is pumped, sufficient to fill tho space between the wall of the tank and the eircumferonce of the holder. Tho obtaining of this supply of water has been one of tho chief causes of delay in the sending of gas into the ciiy, as the quantity required is very large, and it bus to bo raised from a well I'J5 feet deep.

the gas entering by a pipe from beneath tho vessel causes it to rise by its superior gravity to that of the surrounding atmosphere, just as a balloon would do, until it stands nearly its wholo height above the surface, escape of the gas being prevented by the water, which it cannot pat-s through. The holder is maintained inn vertical position by iron columns, up which it traverses bv friction rollers.

'Ihcre are to be two of these ' gasometers,' as they are popului'!y but incorrectly dinominated, but only one is yet complete. It will contain 31,400 cubic feet of gas —an enormous quantity to riad nbout, but insignificant when compared to those of some of the larger works in the eld country, where tlicy fuve been constructed to hold one million cubic feet, and there is one at Philadelphia 140 feet diameter, and 70 feet high. This c.t!ers a ttiiking contrast to the early days of gas-making, when such mistaken fears cl explosion were entertained that no gas holder was allowed to be built of more than 6000 feet capacity, and it was enacted that it should be surrounded by a very strong building to resist its effects—a precaution that is now seen to add to instead of lessening whatever dangi r may exist.

Our volatile acquaintance is now ready to go out and enlighten his expectant friends, requiring only to be measured first. 'J his is effected by means of a 5-feet meter, contributed by Milne and i?on, of Edinburgh, rapuble of tiam-mitting 10,0(i0fect. per hour. It, like all others used by the company, is a " wet meter," and consists of a hollow iron drum in which the gas is forced in a particular diiection by the introduction of partitions, thereby maintaining u current that acts upon a train of wlieel-wcrk which causes an index hand to revolve and thus chronicle the amount of the consumption. It thence passes through the ' governor.' an ingenious machine for r gulating tlie pressure to one unifoim standard, so that the extinction of some lights may not unduly augment the pressure on others ielt burning. Fr.ni this point il proceeds through a long r»nge of c ist ir"n pipes of various diameters, and is thence distributed by service pipes to the different burners in the town. 'Die Company has agreed with the City Hoard to light 100 public lamps, but of these only 42* will bo ready to-night, ill consequence of the mains not having been yet laid in some localities. 'I'liey are thus distributed, Queen street 7 ; Hobson street 8 ; Wakefield street, 1 ; Symonds street, 3; Chapel street, 4; tliort'and street, 3; l'dcn crescent, 2; Strain), 1 ; Alt en road, I?; Princess street, 2; AVjndliani street, 1; Yinreet, 1; Alber street, 3 ; High street, I. Besides these thcie am a number of external lamps at public houses, and about 100 lights at various places of business. Pome of the fittings already placed, are of a most tasteful and expensive character, and add very much to the attractiveness of the establishments where they are erected. Mr. Wart, the manager, lias every confidence in the excellenc of the gas, which is made from the very ) est Lesmahago coal, mixed with Newcastle, and in his ability to supply any demand, however extended that may be, made upon the capabilities of the works. Witli the appliances at present available, lie can manufacture H,OUO cubic feet every twenty-four hours, and ample provision has been made for increasing this to any required extent. Every part of the pbmt is of the newest and best construction, and the £-0,000 which the company has expended has evidently been laid out with great judgment and experience. It now only remains with tlio public to render the Auckland Gas Company a great and pornian cut success.