Welding

—The art or proce of incorpo- Weight of Coal.—The weight of coal in | rating two pieces of wrought metal together the solid lump is from 70 to 80 pounds per while at a white heat, when they are in a cubic foot for bituminous grades, and from plastic or semi-fused condition. The pieces _ 85 or 90 to 100 pounds per cubic foot for to be welded are scarfed, formed into a bird’s -anthracite grades. When broken up in mouth, or else simply upset and butted together. Large pieces may be glut welded by the ordinary commercial sizes, however, its addition of stick-in pieces on either side of the weight, ın bulk, is usually from 50 to 54 pounds joint. A variety of fluxes are used, to preserve per cubic foot for bituminous, and from 53. to 58 the metal from forming a film of oxide or to clean pounds per cubic foot, for anthracite. These, the surfaces; of these borax is probably the best. weights correspond to an allowance of from 42 to 45 cubic feet per ton of 2240 pounds for bituminous grades, and from 39 to 42 cubic feet per ton Welding Converter.—A special type of for anthracite grades. In estimating the capacity transformer for use in electric welding. It of coal bunkers, the above figures are usually faken varied however, by the size of the lumps has two laminated cores, and linked with of coal. them a heavy copper casting which is the secondary coil with only one turn.