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 Brent Future based on ICE Futures Brent index at expiry. The index represents the average price of trading in the 25-day Brent Blend, Forties, Oseberg, Ekofisk (BFOE) market in the relevant delivery month as reported and confirmed by the industry media. Only published cargo size () trades and assessments are taken into consideration. The index is calculated as an average of the following elements: 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,