The process commonly referred to as business-as-usual has given rise to dangerous climate change, but its social history remains strangely unexplored. A key moment in its onset was the transition to steam power as a source of rotary motion in commodity production, in Britain and, first of all, in its cotton industry. This article tries to approach the dynamics of the fossil economy by examining the causes of the transition from water to steam in the British cotton industry in the second quarter of the nineteenth century. Common perceptions of the shift as driven by scarcity are refuted, and it is shown that the choice of steam was motivated by a rather different concern: power over labour. Turning away from standard interpretations of the role of energy in the industrial revolution, this article opens a dialogue with Marx on matters of carbon and outlines a theory of fossil capital, better suited for understanding the drivers of business-as-usual as it continues to this day.