ROUND THE GAS WORKS.

Gisborne Times, Volume XXVII, Issue 2612, 21 September 1909, Page 5

ROUND THE GAS WORKS.

GISBORNE’S LIGHT IN EMBRYO.

NEW EXTENSION SCHEME,

A grimy, dimly-lighted, brick buiid* ing, whose roof is lost in shadows. A row of blackened iron cylinders that tower into upper obscurity like the pipes of some infernal organ. Opposite lies a heap of jet-like coal that glitters in the light coming through the sunlit gap that marks an empty doorway. A bare-armed workman clinks open one of the iron traps set in the massive brick and metal bed from which spring the tall cylinders and we are looking into a long dazzling tube that glares and shimmers with an incandescent beat. There is a scrape and a clatter as the man stoops down and shoots a shovelfull of coal into the gap; the black lumps rattle down the flue, and then—they have vanished, and in their place little blazes of fire have blossomed in a second on the white-hot sides. Hie man is shovelling away at top speed now, and the flames are mixed with ’smoke as they curl and writhe in their prison. Smoke and fire belch through the orifice till the dull building is illuminated with a ruddy glow, and one can scarcely bear to stand within three yards of the furnace door. One last shovelful in the teeth of the spouting flames and with a crash the iron trap is banged to! And apart from the faroff murmur of fire, and a little hanging smoke and coal dust, the place is as it was before.

Such is the scene in the retort-house at the Gisborne Gas Works, when tho coal from which the illuminant is made enters upon the first stage towards tho lighting of the town. The cylinders—there are twenty of them—are the retort tubes through which the hot vapor from the decomposed coal passes, leaving only coke in the beds. The latter are kept at an enormous heat by furnaces underneath, and one has only to see the way a shovelful of coal hursts into flames when shot- into tho flue to gain some idea of tho temperaturo of that white-hot passage. Not only the gas, hut the volatile tar passes off in vapor form, tho latter, however, being condensed in a complicated arrangement of huge tubes. These come down on the outside of tho retort house and disappear into tho ground. The first of the tubes is decidedly hot, the- second a little less so, while the last is quite cold, and conducts away only gas, the tar being run off by a tap into a large underground tank from which it Can be pumped when wanted. But the gas is by no means pure at this stage, and lias to be forced by a little exhausting engine through large iron tanks, or vessels., e filled purifiers. The chief impurity in tho gas, which also contains carbonic acid,is sulphuretted hydrogen. For extracting this ferric oxide is used. The gas passing through the latter leaves the sulphur behind it, the substance becoming ferric sulphide. This, by being exposed to the air, is revivified. That is to say, tlie oxygen in tho atmosphere again combines with the iron, displacing the sulphur and once more becoming ferric oxide, which can be used again to purify the gas. One can see large circular* patches of the rusty ferric oxide on the ground at the gasworks, growing darker according to the number of times the material has been used, till at last it becomes almost black and is shovelled away in a heap, as being useless for the purpose of extracting any more sulphur. The purified gas is then conducted into tho red-painted cylindrical bells or holders that in all large towns form a landmark by which tho local gasworks can readily be located. These holders are raised automatically by the pressure of tho rising gas and are absolutely airtight by reason of their standing in water. The gas can be stored in them till wanted, and turned into the mains through a broad outlet pipe. Just now the Gisborne gasworks present a rather chaotic appearance. Pipes and pieces of machinery are lying about the yard, while several excavators bear witness to proposed building operations of an extensive nature. This marks the progress of a new extension scheme that is to increase the productive aapacity of tho works by over a hundred per cent. Enlargements were decided upon by the company many months ago, and to carry them out Mr. Henry Hoare was brought to Gisborne as engineer and manager. The need for extension has been, felt more than ever during the past winter when every one of the twenty retorts which are contained in four beds in the retort house was kept in, full blast, manufacturing gas at a rate of over thirty million feet a year. The retort house is going to be more than doubled in size and the excavations alongside the present buildings are to contain four more beds which will, however, hold six instead of five retorts. This will increase the manufacturing scope of the plant by a hundred and twenty-five per-cent and will mean a possible output of seventy million feet annually. ’ In the past, and for that matter, at present, one little engine of less than four horse-power has to be relied on for pumping the gas through the purifying tanks. Last week, however, another engine of double power arrived at the works and will be fitted up shortly. This was ordered from an English, firm on March 10th and was not delivered till last Wednesday. “British firms can’t be surprised at Yankees getting the trade, if they are as slow as that,” said Mr. Hoare to the writer, the other day. One excavation that is to be seen at the works represents the situation of another new purifier, four times the size of the present apparatus. This is being built of reinforced concrete, and the materials are all of colonial manufacture. The Gas Company has now been in existence twenty-six years, and an interisting illustration of its gradual progress is to be seen in the three holders that stand in the yard. The first has a capacity for 7,000 cubic feet, the secand 15,000, and the newest 60,000. The holder, however, that is to stand on the place marked by a large circular foundation will have twice the capacity of the other three put together. To give the increased supply a fitting conduit it will be fed through nine-inch pipes in place of the present six-inch pipe. The new pipes are on board the s.s. Indralema, which is now almost due at Auckland, and .will be delivered here shortly. „ Among the improvements that have already been made at the works, are the enlargement and alteration of the office, and the display of up-to-date lamps and stoves that are now to be seen there. Lamps of every conceivable shape hanging from ceilings like fruit on a tree, represent varying candle-power at- diverse prices. _ Anti while in the part of the premises already described gas is manufactured by the thousand feet,' it is here that gas-bills are manufactured by the yard —or inch, according to the amount consumed.