At the age of eighteen Mundella left Kempson's to become first a journeyman, then overseer (in which post he earned £200 a year and a commission on profits) and ultimately manager of a large warehouse set up by another hosiery manufacturing business in Leicester, Harris & Hamel. Richard Harris was a prominent Liberal – and Chartist – in Leicester. Mundella prospered and, while still eighteen, he married. He worked for Harris for three years, until he was 22, and while he was at Harris's the firm experimented seriously and in great secrecy with machinery driven by steam power. Mundella was not technically-minded, though his experience at Harris's with mechanical experimentation helped to form his abiding interest and fascination in new steam-powered hosiery-making machinery. He was one of the first men in the Midlands to realise that steam power was something far more than a means to great wealth. He believed that it could be "so applied and developed as to lift the mass of workers out of serfdom".