Incandescent light bulb street in the world to be lit by an incandescent lightbulb was Mosley Street, Newcastle upon Tyne, United Kingdom. It was lit by Joseph Swan's incandescent lamp on 3 February 1879. Thomas Edison began serious research into developing a practical incandescent lamp in 1878. Edison filed his first patent application for "Improvement In Electric Lights" on 14 October 1878. After many experiments, first with carbon in the early 1880s and then with platinum and other metals, in the end Edison returned to a carbon filament. The first successful test was on 22 October 1879, and lasted 13.5 hours. Edison continued
World's Columbian Exposition their costs at $554,000 but Westinghouse under bid them by 70 cents per lamp to get the contract. Westinghouse could not use the Edison incandescent lamp since the patent belonged to General Electric and they had successfully sued to stop use of all patent infringing designs. Since Edison specified a sealed globe of glass in his design Westinghouse found a way to sidestep the Edison patent by quickly developing a lamp with a ground glass stopper in one end, based on a Sawyer-Man "stopper" lamp patent they already had. The lamps worked well but were short lived, requiring a small