"It looks full of hard words and signs and numbers, not very entertaining or understandable looking, and I wonder whether it will make people wiser or better. So wrote a cousin of Josiah Willard Gibbs when she happened onto a copy of his most famous paper on thermodynamics lying on his desk. In this book we have taken great pains to eliminate as many of the "hard words and signs and numbers" as possible and still capture the essence of thermodynamics. We have tried to make the subject both understandable and entertaining, while pointing oiit some of the ways in which it has made life better for man. We believe that the story of the development and applications of thermodynamics is as interesting as it is important, and for that reason we have written this book. To paraphrase an old saw, "Thermodynamics is too important to be left to the thermodynamicists. Along with telling about the laws of energy and their applications, we have told about the lives of some of the men who have contributed most importantly to our subject. In addition to the technical applications that are generally associated with thermodynamics, we have written about cultural implications in such diverse fields as poetry and the origins of life. Our treatment of all of these subjects has been influenced by Robert Louis Stevenson's dictum that "There is nothing like a little judicious levity."