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Farallon Island Light
Farallon Island Light is a lighthouse on Farallon Islands, Southeast Farallon Island, California. One of the highest lights in California, it was constructed in 1855 to warn ships approaching San Francisco from the west away from the rocky islands. In later years it was shorn of its lantern, but it remains in use. History Farallon Island Light was constructed on Southeast Farallon Island. After the tower was complete, it proved too small to house a first-order Fresnel lens, and the tower had to be torn down and rebuilt. The lighthouse was lit for the first time in December 1855. In 1939, the United States Coast Guard took over the lighthouse when the United States Lighthouse Service merged with it. The Coast Guard maintained a presence until 1972. By that time, the lantern room and the Fresnel lens had been removed, and an automated aero beacon was placed on the tower. The lens is on display in the San Francisco Maritime National Historic Park visitor center on Hyde Street, whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farallon Island
The Farallon Islands, or Farallones (from the Spanish language, Spanish ''farallón'' meaning "pillar" or "sea cliff"), are a group of islands and sea Stack (geology), stacks in the Gulf of the Farallones, off the coast of San Francisco, California, United States. The islands are also sometimes referred to by mariners as the Devil's Teeth Islands, in reference to the many treacherous underwater shoals in their vicinity.Devils Teeth, Mysterious Sharks Shark Stewards. By David McGuire. Sept. 15, 2014. Downloaded July 8, 2017. The islands lie outside the Golden Gate and south of Point Reyes, and are visible from the mainland on clear days. The islands are part of the City and County of San Francisco. The only inhabited portion of the islands is on Southeast Farallon Island (SEFI), where researchers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aero Beacon
An aerodrome beacon or rotating beacon or aeronautical beacon is a beacon installed at an airport or aerodrome to indicate its location to aircraft pilots at night. An aerodrome beacon is mounted on top of a towering structure, often a control tower, above other buildings of the airport. It produces flashes similar to that of a lighthouse. Airport and heliport beacons are designed in such a way to make them most effective from one to ten degrees above the horizon; however, they can be seen well above and below this peak spread. The beacon may be an omnidirectional flashing xenon strobe, or it may be an aerobeacon rotating at a constant speed which produces the visual effect of flashes at regular intervals. Flashes may be of one, two, or three alternating colors ( described below). In the United States In the United States, the Federal Aviation Administration (FAA) has established the following rules for airport beacons: Flashing rates # 24 to 30 per minute for beacons mark ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Park Service
The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational properties with various title designations. The U.S. Congress created the agency on August 25, 1916, through the National Park Service Organic Act. It is headquartered in Washington, D.C., within the main headquarters of the Department of the Interior. The NPS employs approximately 20,000 people in 423 individual units covering over 85 million acres in all 50 states, the District of Columbia, and US territories. As of 2019, they had more than 279,000 volunteers. The agency is charged with a dual role of preserving the ecological and historical integrity of the places entrusted to its management while also making them available and accessible for public use and enjoyment. History Yellowstone National Park was created as the first national par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Lighthouses In The United States
This is a list of lighthouses in the United States. The United States has had approximately a thousand lights as well as light towers, range lights, and pier head lights. Michigan has the most lights of any state with over 150 past and present lights. Lighthouses that are in former U.S. territories are not listed here. Most of the lights in the United States have been built and maintained by the Coast Guard (since 1939) and its predecessors, the United States Lighthouse Service (1910–1939) and the United States Lighthouse Board (1852–1910). Before the Lighthouse Board was established, local collectors of customs were responsible for lighthouses under Stephen Pleasonton. As their importance to navigation has declined and as public interest in them has increased, the Coast Guard has been handing over ownership and in some cases responsibility for running them to other parties, the chief of them being the National Park Service under the National Historic Lighthouse Preservation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clipper Ships
A clipper was a type of mid-19th-century Merchant ship, merchant Sailing ship, sailing vessel, designed for speed. Clippers were generally narrow for their length, small by later 19th century standards, could carry limited bulk freight, and had a large total sail area. "Clipper" does not refer to a specific sailplan; clippers may be schooners, brigs, brigantines, etc., as well as full-rigged ships. Clippers were mostly constructed in British and American shipyards, although France, Brazil, the Netherlands and other nations also produced some. Clippers sailed all over the world, primarily on the trade routes between the United Kingdom and China, in transatlantic crossing, transatlantic trade, and on the New York-to-San Francisco route around Cape Horn during the California Gold Rush. Dutch clippers were built beginning in the 1850s for the tea trade and passenger service to Java. The boom years of the clipper era began in 1843 in response to a growing demand for faster delivery of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold Rush
A gold rush or gold fever is a discovery of gold—sometimes accompanied by other precious metals and rare-earth minerals—that brings an onrush of miners seeking their fortune. Major gold rushes took place in the 19th century in Australia, New Zealand, Brazil, Chile, South Africa, the United States, and Canada while smaller gold rushes took place elsewhere. In the 19th century, the wealth that resulted was distributed widely because of reduced migration costs and low barriers to entry. While gold mining itself proved unprofitable for most diggers and mine owners, some people made large fortunes, and merchants and transportation facilities made large profits. The resulting increase in the world's gold supply stimulated global trade and investment. Historians have written extensively about the mass migration, trade, colonization, and environmental history associated with gold rushes. Gold rushes were typically marked by a general buoyant feeling of a "free-for-all" in income mob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USCG
The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the United States Armed Forces and one of the country's eight uniformed services. The service is a maritime, military, multi-mission service unique among the United States military branches for having a maritime law enforcement mission with jurisdiction in both domestic and international waters and a federal regulatory agency mission as part of its duties. It is the largest and most powerful coast guard in the world, rivaling the capabilities and size of most navies. The U.S. Coast Guard is a humanitarian and security service. It protects the United States' borders and economic and security interests abroad; and defends its sovereignty by safeguarding sea lines of communication and commerce across vast territorial waters spanning 95,000 miles of coastline and its Exclusive Economic Zone. With national and economic security depending upon open global trade ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Francisco Maritime National Historic Park
The San Francisco Maritime National Historical Park is located in San Francisco, California, United States. The park includes a fleet of historic vessels, a visitor center, a maritime museum, and a library/research facility. The park used to be referred to as the San Francisco Maritime Museum, however the former 1951 name changed in 1978 when the collections were acquired by the National Park Service. Today's San Francisco Maritime National Historical Park was authorized in 1988; the maritime museum is among the park's many cultural resources. The park also incorporates the Aquatic Park Historic District, bounded by Van Ness Avenue, Polk Street, and Hyde Street. Historic vessel fleet The historic fleet of the San Francisco Maritime National Historical Park is moored at the park's Hyde Street Pier. The fleet consists of the following major vessels: *'' Balclutha'', an 1886 built square rigged sailing ship. *'' C.A. Thayer'', an 1895 built schooner. *'' Eureka'', an 1890 built st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Lighthouse Service
The United States Lighthouse Service, also known as the Bureau of Lighthouses, was the agency of the United States Government and the general lighthouse authority for the United States from the time of its creation in 1910 as the successor of the United States Lighthouse Board until 1939 when it was merged into the United States Coast Guard. It was responsible for the upkeep and maintenance of all lighthouses and lightvessels in the United States. History 1789–1910 In 1789, the United States Lighthouse Establishment (USLHE) was created and operated under the Department of the Treasury. All U.S. lighthouse ownership was transferred to the government which became the general lighthouse authority (GLA). In 1792, the Cape Henry Lighthouse was the first lighthouse built by the USLHE. In 1822, French physicist, Augustin Fresnel designed the Fresnel lens. In 1841 the Fresnel lens was first used in the United States and installed on the Navesink Lighthouse. In 1852 the Lighthouse Bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territories of the United States by population, most populous U.S. state and the List of U.S. states and territories by area, 3rd largest by area. It is also the most populated Administrative division, subnational entity in North America and the 34th most populous in the world. The Greater Los Angeles area and the San Francisco Bay Area are the nation's second and fifth most populous Statistical area (United States), urban regions respectively, with the former having more than 18.7million residents and the latter having over 9.6million. Sacramento, California, Sacramento is the state's capital, while Los Angeles is the List of largest California cities by population, most populous city in the state and the List of United States cities by population, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Coast Guard
The United States Coast Guard (USCG) is the maritime security, search and rescue, and law enforcement service branch of the United States Armed Forces and one of the country's eight uniformed services. The service is a maritime, military, multi-mission service unique among the United States military branches for having a maritime law enforcement mission with jurisdiction in both domestic and international waters and a federal regulatory agency mission as part of its duties. It is the largest and most powerful coast guard in the world, rivaling the capabilities and size of most navies. The U.S. Coast Guard is a humanitarian and security service. It protects the United States' borders and economic and security interests abroad; and defends its sovereignty by safeguarding sea lines of communication and commerce across vast territorial waters spanning 95,000 miles of coastline and its Exclusive Economic Zone. With national and economic security depending upon open global trade a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresnel Lens
A Fresnel lens ( ; ; or ) is a type of composite compact lens developed by the French physicist Augustin-Jean Fresnel (1788–1827) for use in lighthouses. It has been called "the invention that saved a million ships." The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional design. A Fresnel lens can be made much thinner than a comparable conventional lens, in some cases taking the form of a flat sheet. The simpler dioptric (purely refractive) form of the lens was first proposed by Count Buffon and independently reinvented by Fresnel. The ''catadioptric'' form of the lens, entirely invented by Fresnel, has outer elements that use total internal reflection as well as refraction; it can capture more oblique light from a light source and add it to the beam of a lighthouse, making the light visible from greater distances. Description The Fresnel lens redu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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