Located at the northern tip of Michigan where Lake Superior, Lake Michigan, and Lake Huron join together, the Sault Ste. Marie Hydroelectric Power Complex was built to harness the hydroelectric potential of the 20-foot falls at the headwaters of the St. Marys (sic) River, the sole outlet of Lake Superior. A century after its construction, the plant remains the largest low-head hydroelectric facility in the United States. Today, the Sault Ste. Marie plant supplies electricity to area residents, especially those in the Upper Peninsula of Michigan.
The third bridge built on the same site to carry railroad tracks across the Susquehanna River just north of Harrisburg, Pennsylvania, the Rockville Stone Arch Bridge, at 3,820 feet long and 52 feet wide, is believed to be the longest and widest stone-arch railroad bridge in the world. A central link in rail travel between New York City and Pittsburgh, the Rockville Stone Arch Bridge accommodates four lines of railroad tracks, today serving both the Norfolk Southern and Amtrak lines.
This was the first successful machine for mechanizing the identification and price marking of retail merchandise. At a single stroke of the operating handle, the machine formed a tag from a roll of stock, imprinted it with price and other information, formed a wire staple, and stapled the tag to the merchandise. This means for dispensing with handmade and written tags amounted to a minor revolution in the then rapidly expanding retail industry.
In 1899, engineers from the City of Chicago's Division of Bridges and Viaducts performed a survey of moveable bridge design in the U.S. and Europe. Their study led to the conclusion that the unusual trunnion bascule design would best meet their needs.
During the post-Civil War era, efforts to cultivate the land for higher crop yields resulted in the digging of thousands of miles of ditches to improve land drainage. Accurately graded ditches were needed for open drainage, pipeline trenches and placement of underground agricultural drainage tile. Teams of skilled workers laid out the direction and gradient of a ditch and dug it out with pick and shovel. The Black Swamp area, where Lake Erie drains into northwest Ohio and southeast Michigan, was the center of much of the U.S. ditching activity.
This low-head operating plant is representative of nineteenth-century hydropower-plant practice using many small turbines in contrast to twentieth-century use of few large turbines and generators. Its 40,000 horsepower capacity made it the largest in the country using turbines of American design (McCormick-Francis). The contemporary and larger Niagara installation used turbines of French design (Fourneyron). The entrepreneur of this plant was Francis Clergue, a lawyer, who employed as his chief engineer Hans A.E. von Schon, a German immigrant who had served with the U.S.