Thermodynamics is concerned with two forms of energy—heat and work. The ability to transform heat into work is important in our modern world, from the steam power plants that provide electricity to the engines that power cars and airplanes. This book takes a fascinating look at the scientists and engineers who advanced our knowledge of thermodynamics, opening up new frontiers in transportation and industry. Key figures include James Watt, James Prescott Joule, Sir William Thomson (Lord Kelvin), and Rudolf Clausius.