Electric light be made with a screw-thread base, two metal pins, two metal caps or a bayonet cap. The three main categories of electric lights are incandescent lamps, which produce light by a filament heated white-hot by electric current, gas-discharge lamps, which produce light by means of an electric arc through a gas, and LED lamps, which produce light by a flow of electrons across a band gap in a semiconductor. Before electric lighting became common in the early 20th century, people used candles, gas lights, oil lamps, and fires. Cornish chemist Humphry Davy developed the first incandescent light in 1802, followed
Brent Crude Brent Crude Brent Crude is a trading classification of sweet light crude oil that serves as a benchmark price for purchases of oil worldwide. This grade is described as light because of its relatively low density, and sweet because of its low sulphur content. Brent Crude is extracted from the North Sea and comprises Brent Blend, Forties Blend, Oseberg and Ekofisk crudes (also known as the BFOE Quotation). The Brent Crude oil marker is also known as Brent Blend, London Brent and Brent petroleum. Brent is the leading global price benchmark for Atlantic basin crude oils. It is used to