WILSON'S HYDRAULIC LIME WORKS, MAHURANGI.

New Zealand Herald, Volume XIX, Issue 6570, 7 December 1882, Page 3

WILSON'S HYDRAULIC LIME WORKS, MAHURANGI.

Ox visiting the above-named works of the firm of J. Wilson and Co., Mr. N. Wilson, one of the partners, and working manager of the establishment, gave me every facility t« make a report on the works, kindly showing me through the premises, remarking to my question as to whether he would allow me to examine the establishment, that he was always glad to see visitors. Messrs. Wilson have just received a lot of new machinery, to meet the extension of trade. It consists of an IS-horse-power Scott's patent boiler, made by Messrs. Fr.iser and Tinne, of Auckland. This is of somewhat novel construction, and possesses large heating surface. The furnaces—two in number —are placed under the shell of the boiler, supplying a want that has long been desired. To prevent injury to the plates, through sediment settling about the fires, the boiler is provided with a leg, which goes below the grates and receives any dirt that may be in the water, thus effectually preventing the plates from heating. The boiler stack and the foundations of all the machinery are of concrete made of this cement lime. The chimney stack is CO feet high, round, C feet at base and 3 feet G inches at top. I suppose this is the first boiler ttack of concrete in the colony. It looks well, and has been erected at less than half the cost of brick. The engine is 17 nominal horse-power, and will work up to 60 or 70 indicated. The grinding machinery consists of a crusher, very much like a large pestle and mortar with the bottom out of it, and is going at a high speed. This machine prepares the lime for the mill-stones, of which there are two sets, four feet in diameter. The stones are fed from the crusher by a set of iron lifts, or elevators, and the ground lime is all passed through fine-meshed sieves, so as to make its uniformity a certainty. Water is supplied for all purposes at the works by 14 inch pipes, leading into a concrete dam, IG3O feet away from the works. The dam is 7 feet high, 3 feet thick at base, and 9 inches at top, and holds 100,000 gallons of water. The machine power now going is capable of grinding 1000 bushels per day ; so it will be seen from this that J. Wilson and Co. are prepared to supply large quantities. They have at present thirteen kilns aud six mere in course of erection, and intend gradually to increase the number as the requirements of the trade demand.

The limestone is close to the kilns—in fact, the kilns are built of limestone. The stone is brought on trams, the waggons being so arranged as to tip the stone into the kilns. The fuel used for burning the lime is also landed on a tram wharf, erected above the floors, and tipped down. Vessels are loaded in the same manner, and need fear no delay either loading or discharging, as there are separate wharves to load lime and discharge fuel. The dimensions of the buildings forstoring lime are : Concrete shed, 4 x 20, capable of storing 3000 bushels, and an iron shed, 30 x 20, storing 2000. Then there are the engine-house and grinding room, 2C x 20— the grinding room being the upper floor— and boiler-house, 12 x 21. There are four houses for workmen, one of which is a concrete cottage, 2S x 2S, with four rooms aud a passage. This is plastered inside and out, and otherwise well finished, and is a good proof of tte value of this material, as the walls are only six inches thick, and built of clay burnt on the spot, instead of scoria ash, and erected at as low a cost as wood.

Hearing that the supply of limestone would soon run out, unless it were brought up from belcw the sea level, which, of course, would necessitate hoisting and pumping gear, I put the question to Mr, Wilson. He laughed, and gave me the following information : —That there was enough limestone on the property of the firm above the sea level to supply 100 tons, or 4000 bushels, per week for the next hundred years. When that was exhausted it might be necessary to consider a pumping scheme, but, seeing that there was so large a quantity easily obtainable, they would have plenty of time to consider that question. I asked how the Portland cement works would affect them, and he answered, not injuriously, for the reason that there was such a difference, aud must of necessity always be a great dilTcrcnze, on account of the expensive process cement had to go through. In illustration of this, he cited the seal lime of France, of which the Suez Canal was constructed. This cement lime is produced in the midst of the cement works of the Old World, yet it has a yearly sale of 1 no,ooo tons, or 90,000 bushels, per week, thus showing how good hydraulic limes are appreciated in the Old World.

The works are iu excellent order, and the Messrs. Wilson deserve the success that is evidently attending their enterprise. There can be no doubt that it is due to the firm's energy that the lime trade of the Mahurangi district is assuming such large proportions. It was knowa for years that some of the limes of this district possessed valuable hydraulic properties, but it is due to the Messrs. Wilson to say that they were the first to put it on the market in a ground form—the only one in which a true cement lime is fit to be used—and they have also shown by the numerous works which they have executed the great number of purposes for which it is fit.—[Own Correspondent.]