Primarily self taught after the age of ten, Granville Woods became a mechanical engineer and an inventor with over 50 patents. Two of his most notable inventions were a “telegraphony” device which allowed communication by voice over telegraph wires, and a Synchronous Multiplex Railway Telegraph that helped trains communicate with stations and other trains about their whereabouts and problem on the track. The first was purchased by Alexander Graham Bell, and the second was challenged in court by Thomas Edison. Woods successfully defended his patent, leading Edison to offer him a prominent job within his company. Woods declined preferring to work independently.