rs later Edison's design was put in use by state legislatures for use by the public in general elections. By the age of twenty-three Edison owned two factories to manufacture telegraphic equipment and had money to pursue his research. On December 25, 1871, Edison married Mary Stilwell. They had three children. Two of his children were nicknamed Dot and Dash after the Morse code. In 1880 Edison made a discovery in science. He noticed that when a metal plate was inserted into a light bulb, the plate became a valve and the current could be controlled.
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