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Fort Point Light, San Francisco
Fort Point Light is a decommissioned lighthouse built on the third tier of Fort Point, San Francisco, Fort Point, which is now directly beneath the south anchorage of the Golden Gate Bridge in San Francisco, California. The lighthouse is at the south end of the narrowest part of Golden Gate strait. It was preceded by two other lighthouses in nearby locations. The present lighthouse was in operation from 1864 until 1934. Structures There have been three lighthouses built in the area where Fort Point stands today. The original lighthouse, built in 1853, was a Cape Cod style lighthouse with an integral tower. It was the second lighthouse to be built on the US west coast, but it stood for only three months, and was never lit. While awaiting the arrival of its lens (from Paris), it was torn down to make room for the United States Army, Army fort. The second lighthouse at Fort Point was a squat wooden tower with four sides that sloped up to a square watch room. It was built on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golden Gate Bridge
The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the strait connecting San Francisco Bay and the Pacific Ocean in California, United States. The structure links San Francisco—the northern tip of the San Francisco Peninsula—to Marin County, California, Marin County, carrying both U.S. Route 101 in California, U.S. Route 101 and California State Route 1 across the strait. It also carries pedestrian and bicycle traffic, and is designated as part of U.S. Bicycle Route 95. Recognized by the American Society of Civil Engineers as one of the Wonders of the World, Wonders of the Modern World, the bridge is one of the most internationally recognized symbols of San Francisco and California. The idea of a fixed link between San Francisco and Marin had gained increasing popularity during the late 19th century, but it was not until the early 20th century that such a link became feasible. Joseph Strauss (engineer), Joseph Strauss served as chief engineer for the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresnel Lens
A Fresnel lens ( ; ; or ) is a type of composite compact lens (optics), lens which reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections. The simpler Dioptrics, dioptric (purely refraction, refractive) form of the lens was first proposed by Georges-Louis Leclerc, Comte de Buffon, and independently reinvented by the French physicist Augustin-Jean Fresnel (1788–1827) for use in lighthouses. The Catadioptric system, catadioptric (combining refraction and reflection) form of the lens, entirely invented by Fresnel, has outer Prism (optics), prismatic elements that use total internal reflection as well as refraction to capture more oblique light from the light source and add it to the beam, making it visible at greater distances. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Government Buildings On The National Register Of Historic Places In San Francisco
A government is the system or group of people governing an organized community, generally a state. In the case of its broad associative definition, government normally consists of legislature, executive, and judiciary. Government is a means by which organizational policies are enforced, as well as a mechanism for determining policy. In many countries, the government has a kind of constitution, a statement of its governing principles and philosophy. While all types of organizations have governance, the term ''government'' is often used more specifically to refer to the approximately 200 independent national governments and subsidiary organizations. The main types of modern political systems recognized are democracies, totalitarian regimes, and, sitting between these two, authoritarian regimes with a variety of hybrid regimes. Modern classification systems also include monarchies as a standalone entity or as a hybrid system of the main three. Historically prevalent forms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lighthouses On The National Register Of Historic Places In California
A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways. Lighthouses mark dangerous coastlines, hazardous shoals, reefs, rocks, and safe entries to harbors; they also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and the advent of much cheaper, more sophisticated, and more effective electronic navigational systems. History Ancient lighthouses Before the development of clearly defined ports, mariners were guided by fires built on hilltops. Since elevating the fire would improve visibility, placing the fire on a platform became a practice that led to the development of the lighthouse. In antiquity, the lighthouse functioned more as an entrance marker to ports than as a warning signal for reefs and promontories, unlike many moder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lighthouses Completed In 1853
A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways. Lighthouses mark dangerous coastlines, hazardous shoals, reefs, rocks, and safe entries to harbors; they also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and the advent of much cheaper, more sophisticated, and more effective electronic navigational systems. History Ancient lighthouses Before the development of clearly defined ports, mariners were guided by fires built on hilltops. Since elevating the fire would improve visibility, placing the fire on a platform became a practice that led to the development of the lighthouse. In antiquity, the lighthouse functioned more as an entrance marker to ports than as a warning signal for reefs and promontories, unlike many ... [...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 Preserva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Rankin (lighthouse Keeper)
James Rankin (February 20, 1844 – January 5, 1921) was a lighthouse keeper in the United States. A native of Killashee, County Longford, Ireland, Rankin emigrated to the United States in 1867. He served in the U.S. Lighthouse Service as the keeper of East Brother Island Light in California from 1877 to 1878. He then transferred to Fort Point Light in San Francisco, where he remained for 40 years, until retiring in 1919. During his tenure he was credited with saving the lives of 18 people. Rankin died in Antioch, California, where he had moved soon after retiring. In 1997, the United States Coast Guard named a buoy tender A buoy tender is a type of vessel used to maintain and replace navigational buoys. This term can also apply to an actual person who does this work. The United States Coast Guard uses buoy tenders to accomplish one of its primary missions of main ... USCGC ''James Rankin'' (WLM-555) in his honor. Its homeport is Curtis Bay, Baltimore. References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Army
The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of the United States Constitution (1789).See alsTitle 10, Subtitle B, Chapter 301, Section 3001 It operates under the authority, direction, and control of the United States Secretary of Defense, United States secretary of defense. It is one of the six armed forces and one of the eight uniformed services of the United States. The Army is the most senior branch in order of precedence amongst the armed services. It has its roots in the Continental Army, formed on 14 June 1775 to fight against the British for independence during the American Revolutionary War (1775–1783). After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784 to replace the disbanded Continental Army.Library of CongressJournals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Francisco
San Francisco, officially the City and County of San Francisco, is a commercial, Financial District, San Francisco, financial, and Culture of San Francisco, cultural center of Northern California. With a population of 827,526 residents as of 2024, San Francisco is the List of California cities by population, fourth-most populous city in the U.S. state of California and the List of United States cities by population, 17th-most populous in the United States. San Francisco has a land area of at the upper end of the San Francisco Peninsula and is the County statistics of the United States, fifth-most densely populated U.S. county. Among U.S. cities proper with over 250,000 residents, San Francisco is ranked first by per capita income and sixth by aggregate income as of 2023. San Francisco anchors the Metropolitan statistical area#United States, 13th-most populous metropolitan statistical area in the U.S., with almost 4.6 million residents in 2023. The larger San Francisco Bay Area ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of cities in the European Union by population within city limits, fourth-most populous city in the European Union and the List of cities proper by population density, 30th most densely populated city in the world in 2022. Since the 17th century, Paris has been one of the world's major centres of finance, diplomacy, commerce, culture, Fashion capital, fashion, and gastronomy. Because of its leading role in the French art, arts and Science and technology in France, sciences and its early adoption of extensive street lighting, Paris became known as the City of Light in the 19th century. The City of Paris is the centre of the Île-de-France region, or Paris Region, with an official estimated population of 12,271,794 inhabitants in January 2023, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golden Gate
The Golden Gate is a strait on the west coast of North America that connects San Francisco Bay to the Pacific Ocean. It is defined by the headlands of the San Francisco Peninsula and the Marin Peninsula, and, since 1937, has been spanned by the Golden Gate Bridge. The entire shoreline and adjacent waters throughout the strait are managed by the Golden Gate National Recreation Area. Geology During the last ice age, when sea level was several hundred feet lower, the waters of the glacier-fed Sacramento River and the San Joaquin River scoured a deep channel through the bedrock on their way to the ocean. (A similar process created the undersea Hudson Canyon off the coast of New York and New Jersey.) The strait is well known today for its depth and powerful tidal currents from the Pacific Ocean. Many small whirlpools and eddies can form in its waters. With its strong currents, rocky reefs and fog, the Golden Gate is the site of over 100 shipwrecks. Climate The G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
