The earliest date of man’s knowledge of the presence of petroleum in the rocks of Ohio and Indiana is unknown. In places a film of oil was observed floating on the surface of streams; occasionally it was observed in water wells, and drillers for salt occasionally found it to their sorrow, for the smell was thought to be injurious to the salt.
Thus, as early as 1819, or forty years before the Drake well, Dr. S. P. Hildreth, one of the pioneer geologists of Ohio, reported that petroleum had been found in a salt well at a depth of more than 400 feet, in the Little Muskingum Valley. While the eruptions of this well interfered with salt-making, the oil afforded “considerable profit” and was “beginning to be used for lamps, in workshops and manufactories.” “It affords,” said Dr. Hildreth, “a clean, brisk light when burnt this way, and will be . . .