This discovery was patented as the "Edison effect".
When he tested the lamp, he observed what he called the Edison effect: an electric charge passed through space from the hot filament to the cold plate in the lighted bulb.
This discovery was patented as the "Edison effect".
When he tested the lamp, he observed what he called the Edison effect: an electric charge passed through space from the hot filament to the cold plate in the lighted bulb.