Incandescent light bulb granted a Hungarian patent (No. 34541) for a tungsten filament lamp that lasted longer and gave brighter light than the carbon filament. Tungsten filament lamps were first marketed by the Hungarian company Tungsram in 1904. This type is often called Tungsram-bulbs in many European countries. Filling a bulb with an inert gas such as argon or nitrogen slows down the evaporation of the tungsten filament compared to operating it in a vacuum. This allows for greater temperatures and therefore greater efficacy with less reduction in filament life. In 1906, William D. Coolidge developed a method of making "ductile tungsten" from
Phase-out of incandescent light bulbs from broken bulbs may be overstated, and can be ameliorated by taking a few simple steps. No mercury is used in the manufacturing of LED lamps, a different technology replacement for incandescent lamps. In addition, LED lamps do not require warmup time in cold weather, and in fact, perform better in colder temperatures, making them an excellent choice for use in cold locations, such as refrigeration units. The initial cost of CFLs and LEDs are higher than that of incandescent light bulbs. Typically this extra cost is repaid in the long-term, as both use less energy and have longer operating