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
Electric pen Electric pen Thomas Edison's electric pen, part of a complete outfit for duplicating handwritten documents and drawings, was the first relatively safe electric-motor-driven office appliance produced and sold in the United States. Edison recognized the possible demand for a high speed copying device after observing the incredible amount of document duplication required of merchants, lawyers, insurance companies, and those of similar occupations. To satisfy this demand, Edison invented the electric pen, which uses a perforating function inspired by the printing telegraph. Edison and his associate Charles Batchelor observed that as this device punctured the paper, a mark was left underneath