1981

Edison's simple and unprecedented instrument allowed for the first time the permanent recording and reproduction of sound, especially the human voice. On December 6, 1877, Edison put tinfoil around the cylinder, turned the handle of the shaft and, shouting into one of the diaphragms, recorded a verse of Mary Had a Little Lamb "almost perfectly." From this machine evolved the phonographs and record industries of the world.

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.

At the site of the first water pumping station providing water and sewage systems to the City of Erie in 1868, the Chestnut Street Pumping Station houses one of the largest steam engines, which pumped 20 million gallons a day. The triple-expansion steam reciprocating engine, which pumped water from the filter plant to the city reservoir, was typical of those used in municipal water pumping stations throughout the country during the late nineteenth and early twentieth centuries.

Clarifying the turbid waters of the Mississippi River for use as drinking water was a formidable challenge. The Chain of Rocks Water Purification Plant provided the first application of a system of flocculation, sedimentation, and rapid sand filtration for water purification.

The system played a major role in reducing the impact of St. Louis' typhoid and cholera epidemic of 1903 that claimed 287 lives. Continued improvements to the plant reduced that number to 91 by 1914. It is estimated that 1,900 lives were likely saved between 1903 and 1915 due to the filtration system.

Montogomery Bell was a land developer and iron maker who purchased the Harpeth Narrows site to expand his industrial empire - which ultimately consisted of 14 iron blast furnaces throughout middle Tennessee.

The Harpeth River makes a tight bend around a steep limestone ridge, losing 17 feet of elevation in a run of 5 1/2 miles. Bell excavated a tunnel through the limestone ridge, creating a shortcut for the river. The hydropower derived from this drop in elevation was used to drive the Patterson Iron Works built by Bell.

"An essential part of the human experience is to create an aesthetic atmosphere."

The George Washington Bridge represented a departure in suspension bridge design. Chief Engineer O.H. Ammann developed a system of stiffening trusses that offered greater flexibility and saved the project nearly $10 million. Initially, just six of the upper eight lanes were paved, but Ammann designed the bridge to easily accommodate a future lower level.

Swiss-born O.H. Ammann (1879-1965) was Chief Engineer for the Port Authority of New York and New Jersey during the bridge's construction. 

This 50,000-ton die-forging press is among the largest fabrication tools in the world. It was designed and built for the U.S. Air Force by the Mesta Machine Company of Pittsburgh, following the discovery of a 30,000-ton press used by the Germans in World War II (later acquired by the Soviet Union). By 1950, a Heavy Press Program was organized to establish a self-sustaining industrial base for a press capable of producing large forgings and extrusions for the United States. The 50,000-ton Mesta press was one of the first built under this program between 1952 and 1955.

The unprecedented innovation of the steam-atmospheric engine by Thomas Newcomen (1663-1729) of Dartmouth and his assistant John Calley stands at the beginning of the development of practical thermal prime movers in the early years of the eighteenth century. Spreading through Europe and then to the Cornwall mines in the New World, it was one of the strategic innovations in world history and the single greatest act of synthesis in the ensuing history of the steam engine.