Early humans harnessed fire and drove back the darkness. By bringing light to the night, they could extend the span of their activities and accelerate the development of culture. A wide range of lightening devices has since been developed. As in other parts of the globe, oil lamps and wax candles were the primary means to lighten the dark hours in traditional Korean society. They were long familiar to Koreans at night until the introduction of modern sources of illumination, such as petroleum lamps and electricity.