This is a book about a little known element in the history of motive power, the animal powered machine. Windmills and watermills survive in most parts of Britain, but animal-powered machines, whether vertical treadwheels or horizontal horse engines, are hardly known, despite the significant contribution they made to the history of mining and agriculture in the late eighteenth century and early nineteenth century. The development of the railways and the availability of coal caused the use of animal power to decline rapidly, but a number of these early machines still survive today. The author identifies the various types of machine, the jobs they performed and how they evolved with the onset of the industrial revolution.