OCR Text |
Show Ferrold. A new artificial stone, which can be melted and cast in moulds, is said to be a compound partly chemical and partly mechanical, of iron, sulphur and silicon, with more or less foreign matter. mat-ter. Its normal color is a dark slate, which can be modified by. pigments. The material baa the hardness of blue-none blue-none and can be worked by the usual tone cutting tools, turned In a lathe or planed- The tensile strength is from 650 to 1, 200 pounds per square inch and compression of 9,000 to 10,000 pounds is withstood. The specific spec-ific gravity is about 2.6; the melting about 800' degrees Fahr. The new stone is described under the name of Ferroid." |