1920-1929

"I propose this evening to speak to you on a new kind of radiation or light emission from atoms and molecules." With these prophetic words, Professor C. V. Raman of Calcutta University began his lecture to the South Indian Science Association in Bangalore on March 16, 1928. Raman proceeded to…

In 1899, during the earliest days of the automobile revolution, A. O. Smith developed a new, lightweight steel car frame. Within a few short years, he was selling these frames to a “who’s who” of car makers including Cadillac, Oldsmobile, and Ford. A. O. Smith’s son, Lloyd Raymond, carried on…

In brilliant collaboration, Carl and Gerty Cori studied how the body metabolizes glucose and advanced the understanding of how the body produces and stores energy. Their findings were particularly useful in the development of treatments for diabetes. In 1947 the Coris shared a Nobel Prize for…

The introduction of penicillin in the 1940s, which began the era of antibiotics, has been recognized as one of the greatest advances in therapeutic medicine. The discovery of penicillin and the initial recognition of its therapeutic potential occurred in the United Kingdom, but, due to World War…

The 1.6-mile Holland Tunnel was the first underwater vehicular crossing of the Hudson River and the first tunnel specifically designed for automobiles and trucks. It dramatically reduced the time required to traverse the Hudson River, a trip previously possible only by ferry. 

A major…

The largest mine hoist in the world, it serves the two incline skipways of Shaft No. 2, almost 9,300 feet long. The overhead winding drum has a diameter of 30 feet, of which the cylindrical center section is 10 feet long. The two 10-foot long end sections taper down to a 15-foot diameter. Wire…

The Connecticut Light & Power Company pioneered the use of pumped storage in the United States at this hydroelectric station. First operated in 1929, the Rocky River Plant had two reversible pumps that somewhat resemble large hydroelectric turbines. This permitted significant improvements in…

The Miami Conservancy District flood control project was the direct result of the disastrous flood of 1913, when waters from the Miami, Stillwater, and Mad rivers flooded Dayton and surrounding communities in the Miami Valley. More than 400 lives were lost and property damage exceeded $100…

This floating dredge is one of the last mammoth gold dredges in the Fairbanks Mining District that traveled an ancient stream bed, thawing the ground ahead of it and scooping up the gravel. During 32 years of operation, a fortune in gold washed through its sluices. Ladder dredges came to Alaska…

The Ljungstrom air preheater is a regenerative heat exchanger, invented in the 1920s and soon used throughout the world. Dr. Fredrik Ljungstrom, then technical director at Aktiebolaget Ljunstrom Angturbin, invented it for preheating combustion air in boiler plants, but the use has expanded to…

The quantities of materials used in the building are staggering: 12,000 tons of structural steel; 42,000 cubic yards of concrete - consisting of 65,000 barrels of cement and 25,000 tons of sand; 360,000 feet of piling; and 10,000,000 bricks. At the time of its construction, Atlantic City…

Hardy fishermen and their families have long inhabited Bailey Island, which was settled in the 1720s. Ordinarily, they did not mind crossing to the mainland in their fishing boats. But before the Bailey Island Bridge was built, during certain seasons of the year when violent storms battered the…

Built by the Bay City Dredge Works of Bay City, Michigan, this dredge was used to construct a portion of US 41 called the Tamiami Trail, which connected Tampa with Miami through the Everglades and Big Cypress Swamp. The last remaining display of walking dredges (of some 145 walking machines), it…

Constructed on 1,040 acres just 10 miles southwest of the city center, the Cleveland Hopkins Airport was the first major airport in the world to provide an integrated system of paved landing surfaces, lighted runways, and a terminal complex consisting of hangars and operating facilities.…

A project that combined great engineering ambition and burgeoning civic pride, the Columbia River Highway was built at the dawn of the automobile age out of a desire to bring greater attention to the growing population and natural beauty of the Pacific Northwest. By the time of its completion in…

The Cooperative Fuel Research (CFR) engine is used extensively throughout the world for testing, research, and instruction in the performance of fuels and lubricants for the internal combustion engine. Principal design work on this prototype engine was accomplished by engineers of Waukesha Motor…

Established in 1929, and owned by several different aviation companies through its history, the Downey site was the design, test, and production site for various airplanes and spacecraft that defined American aerospace accomplishments in the 20th century. Its rich legacy includes the P-51…

Wind dynamics were a major consideration in building such a huge structure. When winds blow against the building, they are deflected up over the roof, creating a partial vacuum that can draw the roof up with a force several times greater than the direct force of the wind. Wind tunnel testing on…