1994

The Chamberlain is the only surviving bridge of the original five. The others were replaced as the river rose due to flood control dams put in place over time.

Combining British financing, American engineering, and Canadian contracting, the White Pass and Yukon was the first major civil engineering project on the continent above the 60th degree of northern latitude. Completed in 27 months using only hand tools, black powder, and regional timber, the White Pass and Yukon rises almost 2,900 feet from sea level at the port of Skagway to the White Pass summit on the U.S.-Canada border in just 20 miles, accomplishing one of the steepest climbs of any railroad in the world.

The bridge is 408 meters long and weighed approximately 1,500 metric tons when built. Originally supported by four columns, two more were added in later years to support the weight of heavier rail cars.

Conceived in the early years of World War II as a plan to bury four fuel containers horizontally in a hillside at the U.S. Navy facility at Pearl Harbor, Hawaii, the Red Hill Underground Fuel Storage Facility ultimately encompassed the design and construction of 20 vertical storage tanks - each large enough to contain a 20-story building - buried in the volcanic hillside and connected by tunnels to a harbor-side pumping station more than two-and-a-half miles away.

This machine, designed by Alton S. Newell, efficiently reduced automobile bodies into scrap metal for recycling. A body was fed into the shredder at a controlled rate, and rotating hammers, driven by a 500-hp motor, shredded it into small pieces that were easily shipped. The process took about 10 minutes a car and used less energy than other shredding and crushing machines. 

Built during the 1930s, when Argentina's economy was the tenth strongest in the world, the Kavanagh Building was one of the world's first reinforced concrete skyscrapers and for many years remained the tallest building in South America. Commissioned by Corina Kavanagh and designed by architect Sanchez Lago y De la Torre, the 31-story modernist structure juxtaposes five volumes in a triangular, stair-like configuration that served for many years as a representative symbol of modern Buenos Aires.

This is one of several, similar inclines built in western Pennsylvania during the late 19th century. It was designed by Samuel Diescher (1839-1915) after the great flood of 1889, to provide an efficient means of transportation between Westmont and the Conemaugh Valley. (See also the Monogahela and Duquesne Inclines in Pittsburgh.)

Stretching 242 miles from the Colorado River on the California-Arizona border to its final holding reservoir near Riverside, California, the Colorado River Aqueduct consists of more than 90 miles of tunnels, nearly 55 miles of cut-and-cover conduit, almost 30 miles of siphons, and five pumping stations. Supplying approximately 1.2 million acre-feet of water a year - more than a billion gallons a day - it helped make possible the phenomenal growth of Los Angeles, San Diego, and surrounding Southern California areas in the second half of the 20th century.