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
Tapis crude Tapis crude Tapis crude is a Malaysian crude oil used as a pricing benchmark in Singapore. Tapis is very light, with an API gravity of 43°-45°, and very sweet, with only about 0.04% sulfur. While it is not traded on a market like Brent Crude or West Texas Intermediate (WTI), it is often used as an oil marker for Asia and Australia. The price of Tapis in Singapore is often considerably higher than the price of benchmark crude oils such as Brent or WTI (those commonly referenced in market commentaries). This is because its greater aromaticity (i.e. higher ° API)