Petroleum seeping out of underground reservoirs has been collected and used for light throughout recorded history. In the 4th cent. A.D. the Chinese drilled for oil and natural gas, but in the 1850s, oil was still being recovered by skimming it off the tops of ponds. As whale oil became less abundant, producers looked for new ways to extract oil. Edwin Drake dug the first modern oil well in Titusville, Pa, hitting oil at 69.5 ft (21.2 m), touching off an oil rush in the area. (Most modern wells go down over 4,700 ft (1,432 m).) In 1861 the first oil refinery was set up.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.