Thomas Alva Edison (1847-1931),American inventor. At the age of 23,Edison invented a stock ticker that he sold to a Wall Street firm for 30,000 dollars. With this money,he founded a firm of engineers that turned out inventions like wax paper and the mimeograph. In 1876 he set up a research laboratory in Menlo Park,New Jersey. Here he invented the phonograph,improved the telephone and,after thousands of experiments,succeeded in making a practical light bulb. During his lifetime Edison filed a total of 1069 patents,a record no other inventor has ever approached |