When Edison was fifteen, in 895, he became the first apprentice of Ford Inspector. In 899, he was one of several apprentices who moved to Plist with Ford, when he became chief Sorreter of the Plist branch of InterGang. He was also the first of Ford's apprentices to graduate to adept status, in 902. When Ford was mysteriously killed (presumably by LandOrder) in 908, Edison was promoted to chief Sorreter.
Edison is credited with inventing a spell device called a typewriter, in 913, which helped usher in the age of the Sylph Swarm. However, there is some speculation that Ford Inspector had actually invented the typewriter himself, years earlier, with no intention of ever replicating the device for others to use. It's believed that it took Edison several years after Ford's death to learn how to replicate the device, or else it took that long for him to find the perfect use for it. Of course, there is no evidence that he didn't invent the device himself. Either way, he patented it and became quite wealthy from the invention, though he has remained at his job in InterGang, so far. Which is perhaps not surprising, as he had no need of taking such a job in the first place, considering his family's wealth. Clearly, he works for the love of his job.