To say that Edison was a major influence on life in the 20th century is an understatement. In 1877, Edison worked on a telephone transmitter that significantly improved on Alexander Graham Bell's work by allowing voices to be transmitted more clearly at higher volume. His experiments led to his invention of the phonograph later that year. In 1878, Edison turned to development of a long-lasting incandescent light bulb, then an entire light system that could be supported in a city. In 1888, Edison charged his associate, William K.L. Dickson, to invent a motion picture camera. Dickson developed a device that recorded images on a celluloid strip. In 1891, patent applications were made for the camera, called the kinetograph, and a motion picture peephole viewer. The holder of an astounding 1093 patents, Edison successfully manufactured and marketed his inventions.