A product of the Northern California Gold Rush, the Bridgeport Covered Bridge is believed to be the longest, single-span, wooden covered bridge in the United States. Crossing the south fork of the Yuba River at a span of 233 feet, the bridge was built by the Virginia City Turnpike Company as part of a 14-mile toll road authorized by the California state legislature. The toll road was an essential link connecting Virginia City, Nevada, and the silver-producing Comstock Lode with the centers of California commerce.
USA
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Image Credit: Courtesy Flickr/Rick Cooper (CC BY 2.0)Image Caption: The Bridgeport Covered Bridge, one of the longest covered bridges in the nationEra_date_from: 1862
1970
Founded by Eleuthère Irénéé du Pont (1771-1834), the Brandywine River Mills became the largest maker of explosive black powder in the United States. That success resulted directly from the firm's pioneering use of gunpowder processing machinery driven by water wheels and water turbines.
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Image Credit: Courtesy Flickr/Harvey Barrison (CC BY-SA 2.0)Image Caption: On of the waterwheels belonging to the Brandywine River Powder MillsEra_date_from: 1803
2002
These two water turbines were probably the largest and nearly the most powerful ever built in the United States, supplying direct mechanical power to a manufacturing plant. Their installation between 1871 and 1873 makes them among the oldest surviving water turbines.
A dam at Cohoes diverted water to mills and factories along a power canal system. The vertical-shaft turbines at the mill were said to run at 800 horsepower (600 kilowatt) under a head of 20 feet and were connected to an overhead shaft by bevel gearing.
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Image Credit: Public Domain; Produced prior to 1/1/1923Image Caption: An 1879 sketch of the Boyden Hydraulic Turbine, drawn by James Emerson for his book "Treatise relative to the testing of water-wheels and machinery"Era_date_from: 1871
1975
By the 1890s, the transportation infrastructure of downtown Boston - a maze of narrow, winding streets laid out, in some cases, along Colonial cow paths - proved completely inadequate for the needs of a modern, bustling metropolis. Tremont Street, the city's main thoroughfare, was regularly subject to gridlock from a convergence of foot traffic, horse-drawn conveyances, trolley lines, and electric streetcars. To rectify the problem, the Boston Transit Commission, with Howard A. Carson as chief engineer, was created in 1894 to study remedies.
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Image Credit: Courtesy Flickr/Kan Wu (CC BY 2.0)Image Caption: Prudential Station of the Boston SubwayEra_date_from: 1897
1978
In 1751 Benjamin Franklin published “Experiments and Observations on Electricity, Made at Philadelphia in America.”
Experiments summarized in this booklet determined the existence of positive and negative charges, and the difference between insulators and conductors. This work led to the invention of the lightning rod. Its complete construction was popularized in Poor Richard’s Almanack in 1753. This is the first practical engineering application of electricity.
A unifying theory covering static electricity, lightning, and stored charge was invented.
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Image Credit: Public Domain (Author's Choice)Image Caption: "Experiments and Observations on Electricity" by Benjamin Franklin, currently located at the American Philosophical Society LibraryEra_date_from: 1751
2009
This is the first commercial, human-blood heat exchanger. Developed in 1957, it permitted a patient's body temperature to be safely and rapidly lowered during open heart surgery to any desired and precisely controlled hypothermic level, then during the conclusion of the operation rapidly rewarmed to normal. Prior to this, hypothermic surgery required hours of preoperative, hard-to-control, external emersion cooling and postoperative rewarming.
Its design was a cooperative development between researchers at the Duke University Medical Center led by Dr. Ivan W.
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Image Credit: Courtesy ASMEImage Caption: A disassembly of the Blood Heat ExchangerEra_date_from: 1957
1980
Nicholas Montgomery Powers built the bridge. It was first constructed behind the village, then taken apart and reassembled over the stream. Some residents questioned the idea of re-constructing it, but Powers was so confident of the bridge's durability that he sat on the roof when the final trestles supporting it were removed. From his perch he reportedly said: "If the bridge goes down, I never want to see the sun rise again!"
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Image Credit: Courtesy Flickr/Doug Kerr (CC BY-SA 2.0)Image Caption: The view entering the Blenheim Bridge, before it was destroyed.Era_date_from: 1855
1983
All building materials were made fire-resistant to protect against incendiary bombing. Treatment involved a vacuum process of salt impregnation. During construction, high winds caused a partial collapse of some members. The ruined materials were piled for incineration, but would not burn; so the rubble was buried on site. Years later, a farmer leasing ground on the site plowed up some of the materials. They were reported to still be in good condition.
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Image Credit: Courtesy Wikipedia/Lordkinbote (CC BY-SA 2.0)Image Caption: Hangar No. 2Era_date_from: 1943
1993
When built in 1962, this shovel was the second largest in the world. It was used for the removal of overburden in the surface mining of thin coal seams. In its lifetime, it recovered nine million tons of bituminous coal from depths of 20 to 50 feet for local electric power generation. Standing 160-feet high, weighing 5,500 tons, and moving at speeds up to two-tenths of a mile per hour, the machine stripped about a square mile each year.
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Image Credit: Courtesy Flickr/KellyK (CC BY-SA 2.0)Image Caption: This picture of the Big Brutus Mine Shovel does not fully capture its immensity. To create a comparison, the average person would be slightly shorter than the treads, near the bottom.Era_date_from: 1962
1987
Soon after gold was discovered at Sutter's Mill near Sacramento in 1848, General John Bidwell found gold near the Middle Fork of the Feather River. His discovery brought hordes of miners to the scene and Bidwell Bar was born. The Bidwell Bar Suspension Bridge over the Feather River was one of several suspension bridges built in the region in the 1850s, and is the only one that remains.
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Image Credit: Public Domain (National Park Service)Image Caption: The original Bidwell Bar Suspension Bridge (1856), crossing over the Feather RiverEra_date_from: 1856
1967
Innovations
