<P> After many experiments, first with carbon filaments and then with platinum and other metals, Edison returned to a carbon filament . The first successful test was on October 22, 1879; it lasted 13.5 hours . Edison continued to improve this design and on November 4, 1879, filed for U.S. patent 223,898 (granted on January 27, 1880) for an electric lamp using "a carbon filament or strip coiled and connected to platina contact wires". This was the first commercially practical incandescent light . </P> <P> Although the patent described several ways of creating the carbon filament including "cotton and linen thread, wood splints, papers coiled in various ways", it was not until several months after the patent was granted that Edison and his team discovered a carbonized bamboo filament that could last over 1,200 hours . The idea of using this particular raw material originated from Edison's recalling his examination of a few threads from a bamboo fishing pole while relaxing on the shore of Battle Lake in the present - day state of Wyoming, where he and other members of a scientific team had traveled so that they could clearly observe a total eclipse of the sun on July 29, 1878, from the Continental Divide . </P> <P> In 1878, Edison formed the Edison Electric Light Company in New York City with several financiers, including J.P. Morgan, Spencer Trask, 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 ." </P> <P> Henry Villard, president of the Oregon Railroad and Navigation Company, attended Edison's 1879 demonstration . Villard was impressed and requested Edison install his electric lighting system aboard Villard's company's new steamer, the Columbia . Although hesitant at first, Edison agreed to Villard's request . Most of the work was completed in May 1880, and the Columbia went to New York City, where Edison and his personnel installed Columbia's new lighting system . The Columbia was Edison's first commercial application for his incandescent light bulb . The Edison equipment was removed from Columbia in 1895 . </P>

When did the first light bulb come out