SAFES, FinE-rroop. The manufacture of iron safes for the preservation of money and valuable papers has become one of great importance. The foundation of the plan on which fire-proof safes are still constructed was laid by a Mr. Richard Scott in 1801. Mr. Thomas Milner in 1840 patented a fire-proof safe embodying the same principle, but with some improvements. In 1843 letters-patent were granted to Messrs. Tann for the use of a mixture of pounded alum and gypsum, previously heated and cooled, as .a fire-resisting medium placed between two plates of iron, from 3 to 6 in. apart, which together form the wall of the safe. Milner's plan was to fill the jacket formed by the double-plated sides with sawdust, in which were packed a num ber of small tubes filled with an alkaline solution, and hermetically sealed, or crystals of alum or soda, containing from 40 to CO per cent of water of crystallization. In case
of fire, and the safe becoming heated, the tubes burst, or the crystals melt and satu rate the sawdust with water, which becomes steam, and passes into the inner chamber of the safe, and thus protects the contents, if inflammable, from fire for a considerable length of time. Fire-proof safes are still made on the same principle. Messrs. Chubb use a mixture of alum and a mineral substance they procure from abroad. Many of the safes now made are rooms rather than boxes. A safe deposit company has recently been formed in England (the idea originating in the United States); and in 1875 there was completed in London a large building, in the highest degree proof against fire or thieves. containing about 10,000 safes, which are let out to the public.—See Protection from Fire and Thieves, by G. H. Chubb, 1875.