Edison in Menlo Park
Edison was a poor financial manager and by 1875, he began to experience financial difficulties. To reduce costs, Edison asked his widowed father to help him build a new laboratory and machine shop in Menlo Park, New Jersey. He moved into the new building in March, 1876 along with two associates, Charles Batchelor and John Kruesi. Edison achieved his greatest successes in this laboratory and he was dubbed the "Wizard of Menlo Park."
In 1877, Edison invented the carbon-button transmitter that is still used in telephone speakers and microphones. In December of the same year, he unveiled the tinfoil phonograph. (It was 10 years before the phonograph was available as a commercial product). In the late 1870s, backed by leading financiers including J.P. Morgan and the Vanderbilts, Edison established the Edison Electric Light Company. In 1879, he publicly demonstrated his incandescent electric light bulb. In 1882, he supervised the installation of the first commercial, central power system in lower Manhattan. In 1883, one of Edison's engineers William J. Hammer, made a discovery which later led to the electron tube. The discovery was patented the "Edison effect."
In 1884, Edison's wife Mary died, leaving him with three young children. He married Mina Miller in 1886, and began construction on a new laboratory and research facility in West Orange, New Jersey. The new lab employed approximately 60 workers and Edison attempted to personally manage this large staff. The story goes that when a new employee once asked about rules, Edison answered, "There ain't no rules around here. We're trying to accomplish something." However, the operation in West Orange lacked the intimacy of Menlo Park, and Edison's time was often consumed by administrative chores.