Ever since the Gold Rush days of the 1850s, San Francisco Bay area residents and businesses had lobbied for a bridge joining San Francisco and Oakland. Early studies indicated that the bridge was impractical and infeasible; but in October 1929, President Herbert Hoover (himself an engineer) and California Governor C. C. Young appointed the Hoover-Young San Francisco Bay Bridge Commission to study the question more closely.
Island
YearAdded:
Image Credit:
Courtesy Flickr/David Baron (CC BY-SA 2.0)
Image Caption:
San Francisco - Oakland Bay Bridge
Era_date_from:
1937
1986
The first practical demonstration of this tractor took place in a peat field on Roberts Island on November 24, 1904, and was patented and in production by December of 1907. The existing machine represents the earliest gasoline-powered track-type tractors that were to help revolutionize agriculture, logging, construction, road building, and transportation around the world. Its design and development is credited to Benjamin Holt (1849-1920), president of the Holt Manufacturing Company of Stockton.
YearAdded:
Image Credit:
Public Domain (Copyright Expired)
Image Caption:
The Holt 75 model gasoline-powered Caterpillar tractor used early in World War I as an artillery tractor. Later models were produced without the front "tiller wheel."
Era_date_from:
1918
1981
Galveston Island is a barrier island located two miles off the Texas coast. The island is about 3 miles wide at its widest and about 28 miles long. The Galveston Seawall extends over 10 miles along Galveston's oceanfront, protecting life and property against hurricanes and tropical storms.
YearAdded:
Image Credit:
Courtesy Flickr/Ed Schipul (CC BY-SA 2.0)
Image Caption:
Galveston Seawall and Grade Raising
Era_date_from:
1911
2001
Before the Davis Island Lock & Dam were built, the flow of the Ohio River slowed to little more than a trickle during dry periods. For several months each year, the unreliable flow stranded Pittsburgh's steamboats, towboats, and barges.
The Davis Island Lock & Chanoine Dam experimental project was the first lock and dam ever constructed on the Ohio River. Its achievements also included the first rolling lock gates, the largest movable dam built in the 19th century, and the widest chamber in world history.
YearAdded:
Image Credit:
Public Domain (National Park Service)
Image Caption:
Davis Island Lock and Dam
Era_date_from:
1885
1985
Before the Davis Island Lock & Dam were built, the flow of the Ohio River slowed to little more than a trickle during dry periods. For several months each year, the unreliable flow stranded Pittsburgh's steamboats, towboats, and barges.
The Davis Island Lock &…
Galveston Island is a barrier island located two miles off the Texas coast. The island is about 3 miles wide at its widest and about 28 miles long. The Galveston Seawall extends over 10 miles along Galveston's oceanfront, protecting life and property against hurricanes and tropical storms. …
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The first practical demonstration of this tractor took place in a peat field on Roberts Island on November 24, 1904, and was patented and in production by December of 1907. The existing machine represents the earliest gasoline-powered track-type tractors that were to help revolutionize…
Read More
Ever since the Gold Rush days of the 1850s, San Francisco Bay area residents and businesses had lobbied for a bridge joining San Francisco and Oakland. Early studies indicated that the bridge was impractical and infeasible; but in October 1929, President Herbert Hoover (himself an engineer) and… Read More
