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
John White Howell on display at the Edison exhibit of the General Electric Company were displayed two of the "tar putty" carbon filament lamps made by John W. Howell for the 1890 trial, as well as the tools used by Howell to make said lamps. Seven of Mr. Howell's hand-made 1890 patent trial "tar putty" lamps survive today in a collection of rare, historic lamps discovered in 2004. In 1893 Mr. Howell was appointed chief engineer of the Edison Lamp Works of the General Electric Company, which had taken over the Edison lamp works, holding that position until his retirement in 1931. From