Excerpts from Books and Wikipedia
"Historians Robert Friedel and Paul Israel list 22 inventors of incandescent lamps prior to Joseph Swan and Thomas Edison. 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." [Wikipedia] "Thomas Alva Edison, the supreme US inventor of his day, was born at Milan in Ohio in 1847. He had almost no schooling, but set up a laboratory in the basement at home when he was 10." [Furtado: 1001 Days]