At the age of 16 Alexander started to help teach young deaf mutes ; children who could not hear or speak. He used his father's system of 'visible speech' and achieved anazing results. A few years later, while working in London, Alexander met two men who would play an important role in his life. Mr Alexander Ellis, a professor of philology, and Sir Charles Wheatstone, an expert in telegraphy, started him thinking about sending sound through a machine.