Though petroleum was not unknown, millions of American households were still burning candles, whale oil, and other illuminants.

Not until 1859 did our ancestors realize that, concealed in the rocky of western Pennsylvania, lay apparently inexhaustible quantities of a liquid which, when refined, would give a light exceeding in brilliancy anything they had hitherto known.

The mere existence of petroleum, it is true, had been a familiar fact for centuries.

Herodotus mentions the oil pits of Babylon, and Pliny informs us that this oil was actually used for lighting in certain parts of Sicily.

It had never become an object of universal use, simply because no one had discovered how to obtain it in sufficient quantities.
No one had suspected, indeed, that petroleum existed practically in the form of great subterranean rivers, lakes, or even seas.