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
Light crude oil Canada at than the US at , resulting in slightly different density values. A wide variety of benchmark crude oils worldwide are considered to be light. The most prominent in North America is West Texas Intermediate which has an API gravity of 39.6° API (827 kg/m). It is often referred to by publications when quoting oil prices. The most commonly referenced benchmark oil from Europe is Brent Crude, which is 38.06° API (835 kg/m). The third most commonly quoted benchmark is Dubai Crude, which is 31° API (871 kg/m). This is considered light by Arabian standards but would not be