Why were visitors to the Philadelphia World's Fair amazed by the Corliss engine?

In 1876, to celebrate the one hundredth anniversary of American independence, the World's Fair was held in the U.S. for the first time. This Centennial Exhibition, in Philadelphia, provided a showcase for industrial power and new inventions. Most famously, Alexander Graham Bell displayed his telephone. Those who attended the fair also marveled at other inventions, such as the typewriter, as well as improved sewing machines, presses, lathes, looms, and other machines.

The single most impressive display, to many people who saw the fair, was the Corliss engine. This engine was a forty-foot, 700-ton motor, which powered the exhibits in the fair's Machinery Hall. Despite its enormous size, the Corliss engine ran almost silently, and it seemed to embody the awesome power of industrial technology. David Wells, an economist who visited the fair, was so dazzled by the engine and the fair's other exhibits that he remarked that "mechanization, like one of our mighty rivers, is beyond control."