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
Thomas Edison flaws as an extremely short life, high expense to produce, and high electric current drawn, making them difficult to apply on a large scale commercially. Edison realized that to connect a series of electric lights to an economically manageable size and using the necessary thickness of copper wire, he would have to develop a lamp that used a low amount of current. This lamp must have high resistance and use relatively low voltage (around 110 volts). After many experiments, first with carbon filaments and then with platinum and other metals, Edison returned to a carbon filament. The first successful test