This episode looks at the scientific titans of the 19th century, whose drive and ambitions created the railways, discovered electricity and devised one of the most explosive ideas ever: evolution. James Dyson looks at the life of Michael Faraday, the impoverished son of a blacksmith who became obsessed with electricity and gave us energy at the flick of a switch. Kathy Sykes explores the many achievements of Lord Kelvin, who amassed over 70 patents, wrote the laws of thermodynamics and was responsible for the first transatlantic telegraph cable. Richard Dawkins talks about a great neglected hero of his, Alfred Russel Wallace: the man who nearly pipped Darwin to the theory of evolution. And James Dyson explores the life and vast accomplishments of Isambard Kingdom Brunel.