Gilded Age (1878-1889) Thomas Edison's electric lamp patent drawing and claim for the incandescent light bulb First Public Demonstration of Edison's Light Bulb December 31, 1879 Edison did not work on creating the incandescent electric light alone. He was assisted by Francis Upton, a 26-year-old graduate of Princeton University with a master's degree in science. Upton provided the mathematical and theoretical expertise that Edison lacked. In October 1879, they produced a bulb with a platinum filament. But platinum was too expensive, so instead they found that a carbon filament provided a good light at a cheaper price. Although there were problems with the early incandescent lighting systems for years, Edison's reputation as the world's greatest inventor was firmly established. page 3 of 3 Library Of Congress | Legal Notices | Privacy | Site Map | Contact Us