Artificial Marble and Stone.

Progress, Volume II, Issue 6, 1 April 1907, Page 230

Artificial Marble and Stone.

We aieso accustomed to legaid stone as a natuial product that artihcial stone — although making headway in the building industiies — lias become almost a by-word fho Litliogiaphic Stone and Marble Company (Limited), oi Pondei's End Middlesex, and 11 and 12, Fm&bury -square, EC, have, however, brought out undei a recently patented process results of an extiaoidmar\ character Marbles and building stones, fiom the most expensi\e to the most common kinds, aie repioduced with marvellous fidelity All stones are made from waste debris and blast furnace slag even 1, also utilised for the manufacture of high-class marbles The technical descnption ot the process ma}' thus be given A pure carbonate of lime is composed of 561b of lime and 441b of carbonic acid gas The necessai v amount of stone is calcined m closed retorts for the pin pose ot liberating the gas and obtaining lime The gas thus obtained is hquehed and stoied in bottles foi futine use 'I he oxide is then w ithdiawn

and mixed in a revolving drum, with a certain proportion of the ground carbonate. When the lime and fine powder are thoroughly mixed, the whole is slaked The hydrate of lime thus obtained is now in a fit state for pressing into slabs or other forms desired Should, however, a coloured marble be desired, the colour, which is principally due to iron in its various combinations, is thoioughly mixed with the proportionate parts of the limestone and lime Ihe whole is then slaked This method ensuies absolute evenness of colour throughout the mass, whethei it be red, sienna, green, black, or othei colour. The plastic material is now taken to a hydraulic press capable of exerting a pressure which will give a cubic measurement to the block equal to the best and closest grained stone to be found in natuie. After the stones are removed from the p-ess, they are taken to a drying room to expel the remaining moistuie The desiccated blocks are then placed m a cylinder, a vacuum is created, and the carbonic acid gas originally exti acted from the limestone and stored is now brought into action. The gas is first fed into the tank at piactically no pressuie, but the assimilation of the gas by the lime is so rapid that heat is speedily generated So long as heat is maintained, the tank lequires feeding regularly only, but if signs of decrease aie shown, then pressure must be gradually applied until such time as the gauge remains stationary When this occurs, the lime previously disseminated throughout the mass has become carbonate again and the blocks are not to be distinguished from the natural stone. All this, however, conveys but a faint idea of the beauty of results, which possess durability and uniformity unequalled by the natural marble itseli. Natural marbles when carved become very costly. By the company's treatment, at an intermediate stage, floral and other designs can be easily produced pnd the laboui upon the finished article is infinitesimal when compared with that upon the natural stone The company also produces all kinds of building stones uspcl in masonry, whether they are compact, magnesium, or ohti ; We have inspected samples of Portland, Bath and Hopton Wood stones, which are not to be distinguished from the quarried products. These stones are not only superior in quality, as is admitted by the foremost buildingstone experts, but they have many advantages over the natural stones They can, in most cases, be moulded to the required design When this is impossible, the masonry required is done at the intermediate stage, and at less than one third the cost of dressing the natural stone They can if needful, be produced from |in. to any desired thickness — Builder.