Table 3. Power Supply Systems

Elmer Ambrose Sperry was born near Cortland, New York, on October 12, 1860. Sperry, whose mostly absent father was a farmer and itinerant worker and whose mother died hours after his birth, was raised by his aunt Helen until she married, as well as by his paternal grandparents. The young Sperry often studied the many water-driven mills, a steam-driven mill, and the railway station in Blodgett Mills. Later, he also became a familiar presence at the mills, factories, blacksmithy, machine shop, printing press, foundry, railway yard, and pottery of the larger Cortland.

A turning point for Sperry was his attendance at the Philadelphia Centennial exposition in 1876. Sperry was particularly fascinated by the Machinery Hall, observing for hours, for example, a Jacquard loom incorporating an early version of card punch automatic control.

The YMCA greatly influenced Sperry, who avidly read the...