A NEW INDUSTRY.

Evening Star, Issue 4760, 4 June 1878, Page 4

A NEW INDUSTRY.

About a mile beyond Abbotsford Station : ( the railway to Balclutha passes over or i through a bed of sharp sand about 17ft in , 1 thickness, which covers an extensive area. : ] How long it might hare remained uurao- j 1 lested had Mr Hibberd not conceived the \ idea, of turning it to account, it is impossible ; i to say. Small quantities might have been ,' used for mortar had constructive industry ! been content, as in past ages, to allow nature : to manufacture mountains of stone for men to blast and scatter in fragments at immense cast of labor and waste of ma- ' terial. For mining and quarrying, even with modern appliances, in order to obtain ' one squared block of stone for building purposes, destroy at least an equal quantity, j There is aho the. disadvantage of chance j entering in and rendering comparatively j valueless the best-directed efforts. A fault j in Nature's work may mar the beauty of a j block of stone —some foreign substance accidentally deposited in tirewock may weaken its cohesiveness; and, though the labor be- j stowed may not be altogether lost, as the ; block may be applied to inferior purposes, the profit may be gone. Another disadvantage in quarrying stone ii, after blocks have been squared and fitted for their place the substance and weight are greater than-are needed' for the purpose; thus

rendering powerful and slow machinery necessary for raising them to auy height. The expense of building in stone has, therefore, through these combined disadvantages, been rendered prohibitory so far as ordinary house construction is concerned, and even in large buildings, bricks, baked or burned, through the ease with which they can be handlad, have been largely employed, not only in modern but in ancient days. For many reasons asthetic and utilitarian, however," stone is "preferred, and modern invention appears likely to triumph over every difficulty. Latterly concrete has been extensively used, but the somewhat clumsy mode of building with it, has noTprocured favor for its use. However cheap the material, the length of time necessary to consolidate it, and the difficulty of shifting and filling the moulds have proved obstacles to its general adoption. But idea? follow the law of development, and difficulties are overcome as they present themselves. With requisite materials and proper appliances building stone is capable of being manufactured with less labor, _ good and equal in color, free from blemishes, of uniform consistency, and in blocks as easy of transport and more accurately formed than bricks. Whether the manufactured stone is cheaper or not than brick, must be for architects and contractors to deter- I mine. Mr Hibberd, the proprietor, or ODe I of the proprietors of the works, considers it! so, as although one portion of the material is more costly than clay, there is considerable saving of labor in construction, because of

the truth of form of the manufactured stone. MATERIALS USED. There are only two : the rough sharp sand already spoken of, and Portland cement in the proportion of five t6~one. The color of the sand is bright golden mixed with white quartz, and when amalgamated with the cement, it is a good gray, exceedingly even and yeinless throughout. When pointed a building constructed of it would present a very handsome appearance. MACHINERY AND PROCESS. Although to all appearance the sand needs little preparation, in reality it has to undergo preliminary purification. Lumps of clay or other foreign matters that, if left, would interfere with the cohesiveness of the materials and introduce blemishes in the appearance of the stone are mixed with the sand in its natural state, and these must be got rid of. The first process is to thoroughly wash the sand. Water is luckily close at hand, and plentiful; but, in order to get a fall, it has to be pumped up into a reservoir, whence it is conducted by a iiuming to what we may term the washing ground. The reservoir is capable of holding 17,000 gallons of water, and the length of fluming is about 35ft. The sand is couveyed to the washing ground in trucks, running easily upon a woodea iramroad. It is then passed through a screen through which the stream of water rushes, carrying with it all impurities into what w« may appropriately term a tail race. This jpart of the process seems to have been suggested by digging practice, which'it closefy resembles; only instead of sand being washed away to secure gold, it is hoped gold will be secured by the sand 'remaining, Ab&at 100 tons per day can be passed through the screen. Having thus received a thorough purification, the sand is taken to what may be termed the mixing ground. This is conveniently near to the moulding machinery. The sand and cement are carefully

put into a hopper in their respective proportions, and thoroughly mixed and damped to a proper consistency. The mixture is then conveyed to the mouldingroom The moulds are frames of east-iron, which pan be taken from together without disturbing the newly-formed stone. They are divided into three compartments, each of which is subdivided into perfectly squared spaees of exact dimensions. Into the centre of each of these compartments a wooden plug is placed, accurately fitted. The intention is to prevent the compost falling into the centre, so that each rectangular stone, when finished, is hollow. The moulds are then somewhat more than filled with the mixture, and, being placed under a rectangular stamper of equal length with the moulds, so formed as to fall upon the mixture only, it is caused to descend from a height of about 3ft three or four times ; and as it weighs about three tons all superfluous moisture is pressed out, and perfect cohesion between the sand and cement secured. The stamper is easily worked by one man with a powerful winch and is raised by two cams—one at each end! After cleaning off any surplus material by a slide-knife, and thus making the upper edge of the stone perfectly level with the moulds the mould, with its contained stone, is placed on a barrow, taken to the drying or consolidating grounds, placed on a level surface of wood, the moulds are taken irom together, and after covering the newly-formed stone with a wooden casing to protect it from frost or accident, it is left for a time— and a very short time too—to perfect itself. It remains two days and two nights covered.

THE RESULT ILLUSTRATED. It is plain that by this process, as in brickmaking, any size desired might be made • but so far as preparing stone for building purposes is concerned, it has been thouoht advisable to prepare the blocks equal°in width to a brick in length. The thicknessß of the material is about lfin, and the,walls of buildings will be therefore hollow. This is, however, an advantage instead of a disadvantage. So true are the pieces in form that they fit upon each other almost without perceptible joint, so that only ordinary care is required in building with them. Mr Hibberd had had several low walls prepared, showing openings of windows, chimneys, ancl doorways. In order too to prove that the manufactured stone was imperX S fin r ° l? S re ' e had a good-sized bath hUed with water, which, S we were informed, had been standing in it some time Ihe bath was so placed that the under side could be examined, and it was perfectly dry. As a proof, of the cohesive strength of the material, Mr Hibberd had prepared what we may term a brest-Bummer, constructed with the standard blocks, each 18ia x 9in, placed

I perpendicularly to their thickness. The ; stdne-beam wss therefore 19ft long, 18in detep, by 9in thick, resting on each end 'with noj middle support. A slight camber had i been given it to allow for settling, and the ; pieces were cemented together. It appears J thpt no settlement had taken place, and Mr ; Hibberd walked acro.-s it without the ', slightest appearance of deflection. He ex- .' poets when consolidation has. been perfected | to demonstrate that it is capable of supporting a very hea7y load.

OTHER ■PRODUCTS. "While mainly the demand is expected to be for building blocks, the process is equally adapted to the manufacture of drain pipes, troughs, and facings for retaining walls. A vejry inget ims contrivance for the latter was shown us, consisting of a level face, about lMn thick, with a projecting fillet for the inner part which can be built in or filled up with clay or earth, or other material. CONCLUSION. Itjis hardly within our province to enter into the question of price, as we are not supposed . to .be able to go into calculations pertaining to professional av cations. Bub in, view of the advantages promised such a consideration will naturally crop up. Some idea, therefore, may be formed of the value of' the process by the fact that a small cottage 26ft. 9in. long, 13ffc. Gin. wide, and 10ft. high was completed, painting and everything included, for LBO. ; For large buildings there seems likely to be saving of labor and material in a variety of ways. In the maufacture of stone, as in the preparation ofi wood, machinery seems destined to

wonderful revolutions through the absolute accuracy and smoothness of surface obtainable. There will, therefore, probably be great saving in plastering walls, and smoother surfaces will be provided to paint on or attach paper to. Houses built with hollow Wills are more equable in temperature and drier than those generally erected. The material skilfully used is almost safe against vermin, and danger from fire would bej reduced nearly a minimum. The factory is jin it 3 infancy, and ingenious as are its present labor-saving appliances demand would justify the use of powerful machinery, which would increase the supply and tend to ch/eapen production. We think the new enterprise every prospect of success.