MI

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.

This collection includes many examples of advances in mechanical refrigeration for residential and commercial applications, dating from about 1890 to 1960. Such devices dramatically improved food storage safety and convenience and set high standards for mechanical reliability. The RRM collection contains products of such pioneers in the refrigeration industry as Frigidaire, Philco, Sunbeam, and Tecumseh. An archive is available to help researchers trace the history of the refrigeration industry.

In 1900, Moses Gomberg, Professor of Chemistry at the University of Michigan, confirmed the existence of a stable, trivalent organic free radical: triphenylmethyl. In so doing, he challenged the then prevailing belief that carbon could have only four chemical bonds. Gomberg’s discovery made a major contribution to theoretical organic chemistry and fostered a field of research that continues to grow and expand. Today, organic free radicals are widely used in plastics and rubber manufacture, as well as medicine, agriculture and biochemistry.

When Ford Motor Company introduced its new Model T on October 1, 1908, even an inveterate optimist like Henry Ford (1863-1947) could not predict the vast changes that his rather homely new vehicle would produce. What flowed from this series of bold innovations was more than an endless stream of Model Ts — it was the very foundation of the twentieth century itself. The assembly line became the century's characteristic production mode, eventually applied to everything from phonographs to hamburgers.

The Mackinac (pronounced "Mack-in-awe") Bridge (1957) spans the Straits of Mackinac between Lake Michigan and Lake Huron, connecting the Lower and Upper peninsulas of Michigan.   Prior to the construction of the bridge, a fleet of nine ferries would carry as many as 9,000 vehicles per day, with traffic backups stretching as long as 16 miles.

This dynamo, connected directly to a high-speed steam engine, was one of six that produced direct current at Thomas A. Edison's electric power station at 257 Pearl Street in New York City. The Pearl Street Station was the prototype for central station power generation. Edison set out in 1878 to provide an electrical distribution system to bring lighting into the home: His first filament lamp lit on October 21, 1879. With the help of Frances Upton and C.L. Clarke, Edison built his engine-driven dynamo for the 1881 Paris Electrical Exposition.

The Detroit-Windsor Tunnel is a 5,160-foot structure that carries traffic under the Detroit River between Detroit, Michigan and Ontario, Canada. Privately financed, built, and owned, it was completed in 26 months, 10 months ahead of schedule. 

The concept of heating a number of buildings in the core area of a city from a single heating plant was introduced into the United States by Birdsill Holly at Lockport, New York, in 1877. The gain in thermal efficiency of a single large steam plant over a series of small isolated boilers led to widespread commercial installation of district heating. Organized by the Detroit Edison Company, the Central Heating Company began service here in 1903, supplying twelve customers with steam piped from the Edison Company's Willis Avenue Plant. Today's greatly enlarged system continues in operation.