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 considered light if produced in the U.S. The largest oil field in the world, Saudi Arabia's Ghawar field, produces light crude oils ranging from 33° API (860 kg/m) to 40° API (825 kg/m) In the United States, the price of the front month light sweet crude oil futures contract, traded on the NYMEX commodity exchange (symbol CL), is widely reported as a proxy for the cost of imported crude oil. These contracts have delivery dates in all 12 months of the year. From below $20 a barrel in early 2002, it rose to an intraday peak of $70.85 at the