A Fireproofing Process
Among the processes for fireproofing to which the attention of the directors of the Berlin Exposition was recently drawn, and for which awards have been declared, are the following : For light tissues, a composition consisting of sixteen pounds of ammonium sulphates, five pounds ammonium carbonate, four pounds borax, six pounds boric acid, four pounds starch—or one pound dextrine or one pound gelatine and twenty-five gallons water, mixed together, heated to eighty-six degrees Fahr., and the material impregnated with the mixture, centrifugated and dried, and then ironed as usual. One quarter of this mixture, costing only a few cents, is sufficient to impregnate fifteen yards of material. For certain materials, theatrical decorations, wood, and furniture, thirty pound* ammonium chloride are mixed with so much floated chalk as to give the mass comistency, and it is then heated to from 125 degrees to 150 Fahr., two coats of it by means of a brush. A pound of this, costing only a mere trifle, is sufficient to cover five square rods.