If, instead of the acetate of lead, an equal weight of sulphuric acid is added to the sodium hyposulphite, and the process carried on as before, the brass becomes coated, first, with a very beautiful red, which is followed by a green, and changes finally to a splendid brown, with green and red iridescence. This last is a very durable coating and may be especially recommended. By an immersion of 5 minutes brass ar- | Iron treated with this solution takes a ticles may be coated with colors varying steel-blue color, zinc a brown color. from gold to copper-red, then to car- In the case of copper objects the first mine, dark red, and from light blue gold color does not appear. to a blue-white, and at last a reddish-white, according to the thickness of the coat, which depends on the length of time the metal remains in the solution used. The colors possess a very good lustre, and if the articles to be colored have been previously well cleansed by means of acids and alkalies, they adhere so firmly that they may be operated upon by the burnisher. To prepare the solutions dissolve 14 ounces of sodium hyposulphite in 1 pint of water and 1 ounces of acetate of lead previously dissolved in 1 pint of water. When this clear solution is heated to about 190° to 200° F. it decomposes slowly and precipitates sulphide of lead in brown flakes. If metal is present, a part of the sulphide of lead is deposited Graham's Bronzing Liquids. These thereon, and, according to the thick- are used by simple immersions and ness of the deposit, the above colors are have a wide range of application, as produced. To produce an even color-will appear from the three following ing the article must be evenly heated. tables: [It will be found very difficult to obtain by this process the precise shade of color desired, unless the operator has had much experience in its use. The thorough cleansing of the articles from grease by immersion in boiling potash lye and rinsing is absolutely necessary to success. W.] [*Liquid No. 6 must be boiled and cooled. No. 13 must be used at 180° F. or over. No. 6 is slow in action, sometimes taking an hour to give good results. The action of the others is usually immediate. W.] *Made to the consistency of cream. Dead-black on Brass Instruments. | Place about a thimbleful of lampblack on a smooth surface of glass or porcelain, drop 4 or 5 drops of gold size on it, and thoroughly incorporate the same with a spatula. It should form a stiff paste. Use as little of the size as possible, as an excess will give the coating a glossy, instead of the desired dead finish. Add about double the volume of turpentine; mix with a camel's hair brush, and apply to the surface to be coated. (W.) Black. Dark gray. Dark gray. Dark gray. Green-gray. Red (boil). Copper color. Copper color (with agitation). (W.) facturing bronze colors was formerly rubbed fine with a concentrated solution of gum Arabic. By using a concentrated aqueous solution of 5 parts of dextrine and 1 of alum, instead of solution of gum, a far more beautiful and cheaper article is obtained. Preservation of Bronze Monuments. The unsightly, dark coating with which most new monuments of bronze become covered, giving them the appearance of cast iron, does not consist, as has been frequently assumed, of sulphide of copSubstitute for Gum Arabic in Manu-per, but of a mixture of soot and atfacturing Bronze Colors. The coarsely-mospheric dust with the oxides of the powdered metallic dust used in manu- bronze metals. It is impossible to re The most advantageous plan is to combine the comminuted cork with a mixture of clay, lime, solution of waterglass, and a small quantity of hair. move this coating by mechanical means, | sufficient water to form a plastic mass, or by diluted sulphuric acid, but it can which is pressed in moulds and dried be done very quickly and efficaciously in the air. by washing the surface with a concentrated solution of carbonate of ammonium. By this means a layer of patina is formed, which protects the surface of the monument against a renewal of the formation of the black coating. But as this operation requires skilled and experienced workmen, Magnus has devised the following treatment for attaining the same object. The surface of the monument is brushed over, at intervals of a few weeks, with a mixture of 20 parts of acetic acid in 100 of neat'sfoot oil. The acetate and oleate of copper produced thereby form a thin green layer, which prevents an accumulation of dirt and dust, and also causes the formation of a patina. BUILDING MATERIALS, ARTIFICIAL Various Formula for Artificial Stone. Artificial Building Stone. No. 1. Mix 100 parts of hydraulic lime, which has fallen to a powder, with water to form a paste. To this add 250 parts of gravel and 50 of coal ashes, or lixiviated wood ashes. The mass is then thoroughly mixed, and a sufficient quantity of water added to make the volume of the mass equal to 500 parts. It is then poured into moulds made of pine boards, where it is allowed to remain until set. No. 2. One hundred and twenty-five parts of hydraulic lime, which has fallen to a powder, are mixed with a sufficient quantity of water to form a paste. To this are added 250 parts of ground oyster shells and 150 of ground peat ashes, and a sufficient quantity of water to make the bulk of the mass equal to 500 parts. It is then poured into moulds as above and dried. Artificial Building Stone Prepared with Cork. A very light building stone which does not absorb moisture, and does not rot, is prepared according to the following process: Comminuted cork, or cork waste, is mixed with cement, sand, clay, lime, and solution of water-glass, by adding The addition of clay is necessary to prevent the calcium carbonate which is formed from becoming detached from the surface of the comminuted cork wood. The water glass is added in order to form calcium silicate, which contributes to the solidity of the stone. The hair is added to keep the formed stones together while drying. The Artificial Stone from Quartz Sand and Plumbic Oxide. Ground quartz sand is mixed with 2 to 10 per cent. of finely-ground plumbic oxide. harder the stones are to be the more plumbic oxide must be used. The mixture is moistened with water-glass, again thoroughly mixed, and then pressed firmly into moulds. The resulting stone is dried and then burned. E. Schaffer's Artificial Stone (Elizabeth, N. J.). A mixture of 1 part of cement and 3 of sand is made into a dough with diluted sulphuric acid (100 parts of water to 2 of the acid) and subjected to a strong pressure. The stones are then dried in the air for 2 days, when they are again placed for 12 hours in diluted sulphuric acid (100 parts of water to 3 of acid), and finally dried. E. Westermeyer's Artificial Stone (Chicago). Two parts of Portland cement, 1 of sand, and 1 of cinders are mixed together dry and then moistened with an aqueous solution of sulphate of iron. The resulting mortar is pressed in moulds, dried for 2 weeks in a warm place, then placed for 24 hours in water, and finally dried for 4 weeks. F. Coignet's (Paris). Ten parts of unslaked lime are carefully ground with 3 to 4 parts of water and then mixed with 40 to 60 parts of dry sand and 2 to 10 parts of hydraulic cement. The mixture is again ground and pressed into moulds. A. Quesnot's (Bloomington, Ill.). Dissolve 1 part of alum in 15 parts of water, and add 2 parts of hydraulic lime, 10 of sand, and 1 of cement to the required consistency; press into moulds and allow to remain 24 hours. The blocks are fit for use in 14 days, but only become thoroughly hard after longer drying. J. Shellinger, of New York, mixes 4 parts of coarse sand, 1 of cement, with gravel, pebbles, etc., in lime-water to a paste, which is pressed in moulds and the surface covered with a composition of 2 parts of fine sand, 1 of cement, and 1 of dry metallic coloring matter. If the surface of the stone is to be ornamented the design is laid upon the bottom of the mould, and on the top of this is placed the layer of the last-mentioned mixture. When the stone is nearly dry its surface is brushed over with a thin solution of water-glass. Sidewalks of such flags have been laid in several streets of New York, and found to do excellent service. J. Ordway, of Jamaica Plains, N. Y. Thirty parts of quartz sand and 1 of plumbic oxide are mixed to a dough with 10 of water-glass. Suitable coloring substances, if necessary, are added to the mass, which is then pressed into moulds and exposed for 2 hours to a red heat. S. Sorel, of Paris. Natural carbonate of magnesia is heated in a furnace to a red heat for 24 hours; it is then powdered, mixed with sand, gravel, marble waste, etc., or with cotton, wool, and other fibrous substances, in the proportion of to 20 and more to 1, according to the results to be obtained. The mass is moistened with solution of chloride of magnesium, pressed into moulds, or worked and rolled into slabs. Adolph Ott, New York. A mixture of hydraulic cement with lime, soluble siliceous earth, or water-glass is stirred into a stiff dough with a mixture of hydraulic cement and heated dolomite. The mass is pressed into moulds and dried without the use of heat. The dolomite should only be heated to about 750° F., to prevent the carbonate of lime from losing its carbonic acid, and then powdered. Stones manufactured in this manner resemble the Portland stones, and, it is claimed, are harder. "Victoria" Stone (Highton's Process). The refuse of the granite quarries is broken up into pieces of suitable size, and 4 parts of the fragments thus obtained are mixed with I part of Portland cement, with the addition of sufficient water to bring the mass to the consistency of dough. The mass is run into moulds, in which it is allowed to remain for several days, or until it has set solid. The blocks are then immersed in a solution of silicate of soda. (W.) Ransome's Artificial Stone. Clean and dry sand and other suitable siliceous and earthy ingredients are thoroughly incorporated in a mixing mill with silicate of soda. The resulting pasty mass is then pressed into moulds of any required pattern or size, and when set sufficiently, immersed in a solution of chloride of calcium. In the case of large pieces the saturation with chloride of calcium is facilitated by the use of the air-pump. The resulting reaction is the formation, by double decomposition of the ingredients, of an insoluble calcium silicate and of sodium chloride. The first named forms a solid and indurate binding material for the stone, and the sodium chloride is removed by a subsequent thorough washing with water. last operation is important, since if not completely removed from the stone it will make its appearance subsequently in the form of a white efflorescence on its surface. (W.) This Apænite (Ransome's Patent). To avoid the difficulty encountered in washing out the soluble sodium chloride in the process just described, Mr. Ransome devised a process whereby the insoluble calcium silicate should be formed without the simultaneous production of a soluble salt-thus dispensing with the washing process. This he accomplishes by incorporating with the foregoing mixture a material capable of yielding silica in form susceptible of dissolving freely in the presence of free alkali. Such a material is found in the earth known variously as infusorial earth, diatomaceous earth, fossil meal, etc., and which is made up largely of the siliceous coverings of microscopic plants which are readily soluble in caustic soda or potassa. Mr. Ransome introduces some of this earth into his mixture of lime, sand, and silicate of soda solution. When New Plastic Water-proof Grindstones. Melt 100 parts of caoutchouc and add to this 25 parts of sulphur mixed with 450 to 1050 parts of emery or some other abrading substance. Knead the mass thoroughly, press it into moulds, and subject it first in the moulds, and then after it has been taken out, to a temperature of 572° F. To Imitate Variegated Marble. Mix hydraulic lime and ground marble, and incorporate with the mixture a solution of alum and suitable coloring substances. Differently colored masses are then mixed together and cut into slabs. intimately mixed, the mass is intro- | same manner as indicated for artificial duced into moulds and allowed to marble. harden gradually. Calcium silicate is formed by the interaction of the ingredients present, and the mass gradually becomes indurated, forming a compact stone, which improves in strength and hardness as it ages. The action of the siliceous earth introduced is as follows: The free lime and alumina of the mixture seize on the silica of the sodium silicate, forming calcium and aluminum silicate and free soda. This last reacts promptly on the silica of the infusorial earth to form a fresh portion of sodium silicate, and so on, the soda acting as the carrier of silica to the lime, until it is all combined. A portion of the soda appears also to combine at each operation, so that this is gradually united with the lime as a double silicate, leaving nothing to be removed by washing. (W.) Frear's Artificial Stone. A mixture of Portland cement and sand is moistened with a solution of shellac, then reduced to the consistence of dough by the addition of water, and formed by pressure into moulds of any desired shape. After a short time the mass acquires considerable tenacity, and may be removed from the moulds without injury. The "Frear" stone was at one time quite largely used in Chicago and other cities of the West and Northwest. (W.) A. Garvey, of Memphis, Tenn., prepares "lithomarlite" by adding to 3 gallons of water, pint of glue water, and 4 ounces of powdered borax, a sufficient quantity of plaster of Paris to form a dough. An imitation of marble is produced by stirring the coloring substances into the mass. Artificial Marble. The following mixtures have been recommended for making artificial marble. Grind and thoroughly mix: Comminuted stone. Burned calamine PARTS. 280 280 140 140 5 6 3 3 2 1.5 2 40 40 On the addition of the water-glass the ingredients are quickly mixed and thereupon pressed into moulds. The finished pieces are dried at a temperature gradually rising to 125° F. Cement from Blast-furnace Slag. Mr. Ransome has lately wrought out 4000 parts. an important invention by which he is enabled to convert blast-furnace slag into a hydraulic cement having even greater strength than Portland, and besides being much lighter in color. 66 500 Calcium phosphate 45 Feldspar 60 10 250 66 In this process granulated slag is mixed and ground with chalk or lime, 235 parts. or, in his latest practice, with the spent lime of the gas works. resulting mixture is then calcined and again ground. The resulting cement is found to possess high qualities both as regards quick setting and strength. 4 66 1 part. 75 parts. are mixed and the mass treated in the When spent gas lime is used, Mr. |