But the most extraordinary thing about Machinery Hall was the great motor that powered everything else. The Grand Central Engine, sometimes simply called the Centennial Steam Engine, was the largest engine in the world. Weighing more than 650 tons, constructed by the brilliant American engineer George Corliss, it supplied free steam power, via a network of underground shafts totaling a mile in length, to the more than eight thousand smaller machines on display throughout the hall.
