when was the first incandescent light bulb invented
Incandescent light bulb In 1835, James Bowman Lindsay demonstrated a constant electric light at a public meeting in Dundee, Scotland. He stated that he could "read a book at a distance of one and a half feet". However, having perfected the device to his own satisfaction, he turned to the problem of wireless telegraphy and did not develop the electric light any further. His claims are not well documented, although he is credited in Challoner et al. with being the inventor of the "Incandescent Light Bulb".[17]
Incandescent light bulb In addressing the question of who invented the incandescent lamp, historians Robert Friedel and Paul Israel list 22 inventors of incandescent lamps prior to Joseph Swan and Thomas Edison.[8] They conclude that Edison's version was able to outstrip the others because of a combination of three factors: an effective incandescent material, a higher vacuum than others were able to achieve (by use of the Sprengel pump) and a high resistance that made power distribution from a centralized source economically viable.
En plein air Artists have long painted outdoors, but in the mid-19th century, working in natural light became particularly important to the Barbizon school, Hudson River School, and Impressionists.
Incandescent light bulb On 13 December 1904, Hungarian Sándor Just and Croatian Franjo Hanaman were granted a Hungarian patent (No. 34541) for a tungsten filament lamp that lasted longer and gave brighter light than the carbon filament.[31] Tungsten filament lamps were first marketed by the Hungarian company Tungsram in 1904. This type is often called Tungsram-bulbs in many European countries.[56] 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.[57]
Bifocals In 1955, Irving Rips of Younger Optics created the first seamless or "invisible" bifocal, a precursor to all progressive lenses.[2]
Thomas Edison In 1878, Edison formed the Edison Electric Light Company in New York City with several financiers, including J. P. Morgan, Spencer Trask,[60] and the members of the Vanderbilt family. Edison made the first public demonstration of his incandescent light bulb on December 31, 1879, in Menlo Park. It was during this time that he said: "We will make electricity so cheap that only the rich will burn candles."[61]