Thomas A. Edison seen here in 1929 holding a replica of his first lamp.

On December 31, 1879 Thomas A. Edison gave the first public demonstration of the incandescent lamp in Menlo Park. He is seen here in 1929 holding a replica of his first lamp, which had the power of 16 candles. In contrast, the lamp on the left had the power of 150,000 candles. (UPI Photo/Files)