When opened in 1909, the 1,470 foot long main span of the Manhattan Bridge was the third longest suspension bridge span in the world, after the nearby Brooklyn and Williamsburg Bridges. The Manhattan Bridge has two 725 foot long suspended side spans for an overall length of 2,920 feet. The bridge deck is supported by 4 main cables of 20.75 inch diameter, each composed of more than 35,000 individual wires. The bridge deck is stiffened by four parallel trusses of 24 foot depth, hinged at the towers.
USA
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Image Credit:
Courtesy Flickr/Dave Herholz (CC BY-SA 2.0)
Image Caption:
Manhattan Bridge
Era_date_from:
1909
2009
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.
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Image Credit:
Courtesy Flickr/Miss a Liss (CC BY-ND 2.0)
Image Caption:
Mackinac Bridge
Era_date_from:
1958
2009
The Belle of Louisville, built in 1914, is the oldest operating “western rivers” steamboat. It has the shallow-draft flat-bottom hull braced by hog-chain trusses, multiple fire-tube boilers, paddlewheel propulsion, and superstructure configuration that were characteristic of hundreds of steamboats that plied America’s rivers during the 19th and 20th centuries
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Image Credit:
Courtesy Flickr/Bailey Visual Life (CC BY 2.0)
Image Caption:
Belle of Louisville, still in operation
Era_date_from:
1914
2010
At the mountain where the Civil War's Battle Above the Clouds was waged, tourist business has thrived from the building of its first toll road (Whiteside Pike) in 1857 to present day.
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Image Credit:
Courtesy Flickr/Duane Tate (CC BY 2.0)
Image Caption:
Lookout Mountain Incline Railway
Era_date_from:
1895
1991
This steam crawler-tractor emancipated horses from the killing work of hauling trains of sleds over iced roads in the winter woods of the United States and Canada.
Designed, patented (1901), and built by Alvin C. Lombard (1856-1937) of Waterville, Maine, eighty-three "Lombards" were the first practical examples of the often-tried lag or crawler tread that would become the mark of the internal combustion engine-driven agricultural and construction equipment and military tank in current use.
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Image Credit:
Courtesy Flickr/cliff1066,
Image Caption:
Lombard Steam Log Hauler
Era_date_from:
1910
1982
In the 1850s, the Lexington and Danville Railroad began building a suspension bridge over the Kentucky River. The bridge was designed by John A Roebling. Due to unforeseen increases in train loads, the Roebling bridge was never completed. The High Bridge would then be built 20 years later on the existing foundations.
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Image Credit:
Public Domain (Author's Choice)
Image Caption:
High Bridge
Era_date_from:
1877
1985
This machine is an unusual triple-expansion, three-crank rocker engine, which in its day was a high-capacity unit providing outstanding performance for the Boston Water Works Corporation. Designed by Erasmus Darwin Leavitt, Jr. (1836-1916), Engine No. 3 was installed in 1894 to a high-service pumping facility on the south side of the Chestnut Hill Reservoir in Brighton.
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Image Credit:
Public Domain (National Park Service)
Image Caption:
Leavitt-Riedler Pumping Engine
Era_date_from:
1894
1973
Some of the station's notable achievements:
The first method for detecting radioactive particles in water supplies
A successful system of slow-sand filter beds for drinking water
The landmark demonstration that microorganisms carried within filter media could degrade sewage
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Image Credit:
Public Domain (Author's Choice)
Image Caption:
Lawrence Experiment Station
Era_date_from:
1886
1975
As ideas developed, they abandoned infrared radiation to instead concentrate upon visible light. The concept originally was called an "optical maser". In 1958, Bell Labs filed a patent application for their proposed optical maser; and Schawlow and Townes submitted a manuscript of their theoretical calculations to the Physical Review, published that year in Volume 112, Issue No. 6.
Simultaneously, at Columbia University, graduate student Gordon Gould was working on a doctoral thesis about the energy levels of excited thallium.
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Image Credit:
Courtesy of the US Air Force
Image Caption:
A scientist tests a laser at the U.S. Air Force Research Laboratory.
Era_date_from:
1957
The La Esperanza sugar mill steam engine is one of the few remaining American links to the pioneer beam engines of the English inventors Thomas Newcomen (1712) and James Watt (1769). The engine was built in 1861 in Cold Spring, New York, by the West Point Foundry. The general arrangement and details, including the Gothic embellishment, are typical of machinery of the period. The straight-line motion of the piston rod is accommodated to the arc of the moving beam end by a parallel motion. Watt regarded this ingenious linkage as the invention of which he was most proud.
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Image Credit:
Public Domain (National Park Service)
Image Caption:
Hacienda La Esperanza Sugar Mill Steam Engine
Era_date_from:
1861
1979
Innovations
