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
Bonny Light oil Bonny Light oil Bonny Light oil is a high grade of Nigerian crude oil with high API gravity (low specific gravity), produced in the Niger Delta basin and named after the prolific region around the city of Bonny. The very low sulfur content of Bonny Light crude makes it a highly desired grade for its low corrosiveness to refinery infrastructure and the lower environmental impact of its byproducts in refinery effluent. Other grades of Nigerian crude oil are Qua Iboe crude oil, Brass River crude oil, and Forcados crude oil. The Cabinda crude oil is a common grade of crude