" By the 1850s, turpentine production was declining in America. A new competitor surged into the lamp oil market: coal oil, distilled from cannel coal (oil shale) or asphalt/bitumen, a heavy hydrocarbon found naturally in semisolid pools such as Pitch Lake on the Caribbean island of Trinidad and the La Brea Tar Pits in Los Angeles. "

― Richard Rhodes , Energy: A Human History