MECHANICS AND USEFUL ARTS. 57 



worked and applied with a trowel. If then applied to any surface 

 it will firmly adhere thereto, and, upon hardenin2:, produce a firm, 

 water-proof surface, which may be made to resemble stone so 

 closely as not to be readily distinguished therefrom. By makino* 

 the composition still thinner, it may be used as a substitute for 

 paint, and it will also form a strong and adhesive cement for stone- 

 work, etc. 



*' Through a proper choice of the sand or other substances form- 

 ing the basis of my improved artificial stones, etc., or by the use 

 of coloring matter in connection therewith, nearly all descriptions 

 of natural stone may be imitated, and any colors or shades of 

 material obtained, at pleasure. 



" In applying my improved stucco or mastic to buildings, 

 whether of brick or stone, I first wash the surface with my aque- 

 ous shellac solution preparatory to laying on the composition 

 hereinbefore described." 



Making stone "is a business in St. Louis. There is a firm there 

 which makes out of common sand a mantel equal to one of 

 white marble, and sells it for about 10 dollars. The sand in a 

 few hours is converted into rock precisely similar to the strata 

 and ledges beneath the earth that required ages of aqueous and 

 igneous action to form them. The process is strictly scientific 

 and chemical. The materials used are common brown or white 

 sand, soda, flint, chlorine, and calcium. The flint, which is the 

 cementing agent, is melted by being subjected to heat, in connec- 

 tion with soda. Flint, in its chemical constitution, is an acid, and, 

 like all other acids, readily combines with an alkali. Combined 

 with soda, the flint (silica) forms a silicate of soda, — a thick, 

 viscid, transparent substance, very mach like glue. If it is too 

 thin when first made, it is reduced by evaporation in pans till it 

 reaches the proper consistency. It is then mixed with the sand, 

 in a mill from which the mixture comes forth a good deal like wet 

 brown sugar. This substance is called *' pug.'^ It is very plastic, 

 and works as easily in the hand as wet clay or putty. Each 

 moulder has a quantity of the " pug" placed in a box on the end 

 of his work-bench, from which he takes handfuls as he requires it 

 to press into the mould. It matters not whether the mould is a 

 rosette, a diamond, a flower, or a leaf ornament, a ke3'stone, a 

 vase, a pedestal, or a section of a mantel-piece, he* moulds any- 

 thing and everything with equal ease, beauty, and accuracy ; and 

 when the form is taken from the mould the product is a plastic 

 ornament more perfect and beautiful than a carver could execute 

 in a week of constant and patient labor. 



The following is the process of the Messrs. McCaine, of Groton, 

 Mass : — 



"In the preparation of such stone, we use, as a cementitious 

 agent or agents, calcined magnesia and bittern water, and our 

 invention consists in an artificial stone, made by combining, with 

 stone chips and finely pulverized or powdered stone, magnesia 

 and ' bittern water,' the residuum from salt works. 



"The proportions and the process of combination preferred by 

 us are as follows : to 20 parts, by weight, of comminuted stone 



