In the first century AD, a mathematician and tinkerer in Alexandria, Egypt named Hero constructed a toy that boiled water and used the steam to spin a spherical armature using angled jets; 1800 years later, William Avery of Herkimer, New York constructed and marketed a device that used Hero's jet-propelled armature to power foundries, grist mills, and lumber saws. This book, written by a mechanic, traces the many steps, missteps, dead ends, and false dawns leading from Hero to the modern age of internal combustion engines and nuclear plants, and sheds light on the roots of the technology that many of us take for granted, but which shaped and make possible the world that we know.