This biography shows Edison achieving success as an inventor and marrying; then he and his assistants invent the phonograph and the electric light.
In 1929 Thomas Edison (Spencer Tracy) is interviewed and honored at the jubilee of his inventing the electric light. Sixty years earlier young Edison arrives in New York and finds his vote-recorder being used to distill liquor. Ben Els (Henry Travers) gives him a job cleaning up; he reads Faraday on electricity and experiments on a light. Edison can't see Taggart (Gene Lockhart) until he fixes his gold-price indicator. General Powell (Charles Coburn) hires Edison to invent an electric stock ticker. Edison arrives broke in Newark and fixes an umbrella for Mary Stillwell (Rita Johnson). Edison keeps Michael Simon (Felix Bressart) from being laid off by giving him work and finishes the stock ticker. Mary kisses Edison and advises him not to ask for only $2,000. Powell gives him $40,000 for the invention, and Edison asks Mary to marry.
Edison's lab in Menlo Park is constructed. He and his assistants invent things, and he raises a family. Bunt (Lynne Overman) returns and asks him for money, but Edison has bills. Bunt takes the sheriff with his summons out to drink as Edison hides. Els tells Edison he has one week and suggests he invent the light. Edison works day and night, quarreling with Mary. Edison finds Powell ill and goes to Taggart for money. Taggart offers him $100,000 for control; but Edison says no. Edison sadly discharges his men. Tired, he apologizes to Mary and sleeps. In the morning she encourages him, and he finds his men still working. Edison gets an idea for a phonograph, makes a cylinder covered with tin foil, records his voice, and plays it back. Bunt says the talking machine is paying off.
Bunt tells the press stories and that Edison has the light. Taggart says it is false and can't be done. Edison and his men keep testing the light, even trying Ashton's whisker. Edison uses a vacuum to slow the burning. Jimmy Price (Gene Reynolds) tells Edison he wants to be an inventor, and Edison hires him. Edison tries carbon as a filament, and the bulb burns for forty hours before he turns up the current. Edison plans to light New York with his incandescent lamp. Edison tells the board he will build a dynamo, and they give him six months to install his system in 1882. The dynamos go haywire, and they work to repair them in time. At 7 p.m. Edison turns on the lights for New York. Other cities and inventions follow, including the mimeograph, multiple telegraph, storage battery, electric motor, motion picture projector, and the generator. At the jubilee the aged Edison warns against science becoming a monster if it is not balanced by humanity.
This generally accurate account shows how Edison led
a team of scientists and engineers to develop many marvelous inventions
of the electric age, using 99% perspiration and 1% inspiration.