Electric Welding

When two wires or rods of metal are electric current is pa ed through them, the heat developed at the junction softens the metal, and the pieces may be made to IMG:content-1282.jpg:[graphic] Electric Mortar. between two wires within the cavity the sudden expansion of the air will lift the cork from the opening. A quantity of gunpowder discharged in the same way may throw the cork to some distance.