Going as far back as the thirteenth century, Britons mined and burned coal. Britain's supremacy in the nineteenth century depended in large part on its vast deposits of coal, which powered industry, warmed homes, and cooked food. As coal consumption skyrocketed, the air in Britain's cities and towns filled with ever-greater and denser clouds of smoke. Yet, for much of the nineteenth century, few people in Britain even considered coal smoke to be...