Electric light by the first practical electric arc light in 1806. By the 1870s, Davy's arc lamp had been successfully commercialized, and was used to light many public spaces. The development of a steadily glowing filament suitable for interior lighting took longer, but by the early twentieth century inventors had successfully developed options, replacing the arc light with incandescents. The energy efficiency of electric lighting has increased radically since the first demonstration of arc lamps and the incandescent light bulb of the 19th century. Modern electric light sources come in a profusion of types and sizes adapted to many applications. Most modern
Brent Crude price two thirds of the world's internationally traded crude oil supplies. Originally Brent Crude was produced from the Brent oilfield. The name "Brent" comes from the naming policy of Shell UK Exploration and Production, operating on behalf of ExxonMobil and Royal Dutch Shell, which originally named all of its fields after birds (in this case the brent goose). But it is also a backronym or mnemonic for the formation layers of the oil field: Broom, Rannoch, Etive, Ness and Tarbert. Petroleum production from Europe, Africa, and the Middle East flowing West tends to be priced relative to this oil, i.e.