Over three hundred years ago, the first steps were made towards the use of steam power. Most of the steps went beyond the boundary of available technology. The reliable drainage of metal and coal mines was the incentive. Thomas Newcomen using contemporary technology in his beam engine was the first to achieve success, in 1712. Improved by James Watt, the beam engine became the most used form of steam engine in factories, mines and waterworks until well into the second half of the nineteenth century. Examples were still in use into the 1970s. This book outlines the development of the beam engine and gives some explanation of why it was so successful.