Asphalt

—This name is given to three diverse, allied substances: (1) The base or ultimate results of changes in those petroleums or natural hydro-carbons which do not contain paraffin, (2) natural deposits of bitumen, originally derived from petroleums, which are found in the form of self renewing lakes in Trinidad (W. I.), Venezuela, and elsewhere; (3) limestone rock, impregnated with 8 to 20% of bitumen, is found in the Val de Travers, in Switzerland. The derivative from petroleum is often termed mineral pitch, and serves as a waterproof paint, an anti-corrosive covering, etc. Asphalt is often used in cable conduits as it resists moisture, is ductile and can be readily and cheaply repaired.