Science and technology in the United States finish. For example, the British engineer Joseph Swan built an incandescent electric lamp in 1860, almost 20 years before Edison. But Edison's light bulbs lasted much longer than Swan's, and they could be turned on and off individually, while Swan's bulbs could be used only in a system where several lights were turned on or off at the same time. Edison followed up his improvement of the light bulb with the development of electrical generating systems. Within 30 years, his inventions had introduced electric lighting into millions of homes. Another landmark application of scientific ideas to practical uses was the
Charles Edison Electric Company to form the McGraw-Edison Electric Company. Edison was board chairman of the merged company until he retired in 1961. On January 18, 1937, President Roosevelt appointed Charles Edison as Assistant Secretary of the Navy, then as Secretary on January 2, 1940, Claude A. Swanson having died several months previously. Edison himself only kept the job until June 24, resigning to run his gubernatorial campaign. During his time in the Navy department, he advocated construction of the large s, and that one of them be built at the Philadelphia Navy Yard, which secured votes for Roosevelt in Pennsylvania and