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Marcus Hook Range Rear Light
Marcus Hook Range Rear Light is a lighthouse near Bellefonte, Delaware marking a range on the Delaware River. It is the highest light on the Atlantic coast of the United States."The rear range light of Marcus Hook on the Delaware River, 278 feet above the level of the sea, is the highest light on the Atlantic Coast of the continental United States." The lighthouse is visible on the horizon from the windows of high-rise buildings in downtown Wilmington, Delaware. History The permanent structure was preceded by a temporary light on a post, erected in 1915. The present tower was built in 1918 and was composed of nine sections of reinforced concrete; there is also an oil house and a keeper's dwelling on the site. The original beacon displayed a fixed white light using a Fourth order Fresnel lens; this was removed in the early 1980s and replaced with a RL-24 beacon, displaying a fixed red indication. The light was automated in the 1950s, but the keeper's house was occupied by Coast Guar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bellefonte, Delaware
Bellefonte is a town in New Castle County, Delaware, United States. According to the 2010 Census, the population of the town is 1,193. Geography Bellefonte is located at (39.7662246, –75.5093647). The town is roughly centered at the intersection of Brandywine Boulevard and Bellefonte Avenue. According to the United States Census Bureau, the town has a total area of , all land. Climate The climate in this area is characterized by hot, humid summers and generally mild to cool winters. According to the Köppen Climate Classification system, Bellefonte has a humid subtropical climate, abbreviated "Cfa" on climate maps. Infrastructure Transportation Brandywine Boulevard serves as the main street through Bellefonte, passing southwest-northeast through the town. U.S. Route 13 Business (Philadelphia Pike) passes along the northwestern edge of Bellefonte, heading northeast to Claymont and southwest to Wilmington. Delaware Route 3 passes to the west of Bellefonte and provides ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminum combined. Globally, the ready-mix concrete industry, the largest segment of the concrete market, is projected to exceed $600 billion in revenue by 2025. This widespread use results in a number of environmental impacts. Most notably, the production process for cement produces large volumes of greenhouse gas emissions, leading to net 8% of global emissions. Other environmental concerns include widespread illegal sand mining, impacts on the surrounding environment such as increased surface runoff or urban heat island effect, and potential public health implications from toxic ingredients. Significant research and development is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reinforced Concrete
Reinforced concrete (RC), also called reinforced cement concrete (RCC) and ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel bars ( rebar) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as a technique to reinforce the concrete. In terms of volume used annually, it is one of the most common engineering materials. In corrosion engineering terms, when designed correctly, the alkalinity of the concrete protects the steel rebar from corrosion. Description Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made of ... [...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] |
Colonial Revival
The Colonial Revival architectural style seeks to revive elements of American colonial architecture. The beginnings of the Colonial Revival style are often attributed to the Centennial Exhibition of 1876, which reawakened Americans to the architectural traditions of their colonial past. Fairly small numbers of Colonial Revival homes were built c. 1880–1910, a period when Queen Anne-style architecture was dominant in the United States. From 1910–1930, the Colonial Revival movement was ascendant, with about 40% of U.S. homes built during this period in the Colonial Revival style. In the immediate post-war period (c. 1950s–early 1960s), Colonial Revival homes continued to be constructed, but in simplified form. In the present-day, many New Traditional homes draw from Colonial Revival styles. While the dominant influences in Colonial Revival style are Georgian and Federal architecture, Colonial Revival homes also draw, to a lesser extent, from the Dutch Colonial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lighthouse
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 has become uneconomical since the advent of much cheaper, more sophisticated and 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 the 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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leading Lights
Leading lights (also known as range lights in the United States) are a pair of light beacons used in navigation to indicate a safe passage for vessels entering a shallow or dangerous channel; they may also be used for position fixing. At night, the lights are a form of leading line that can be used for safe navigation. The beacons consist of two lights that are separated in distance and elevation, so that when they are aligned, with one above the other, they provide a bearing. Range lights are often illuminated day and night. In some cases the two beacons are unlighted, in which case they are known as a range in the United States or a transit in the UK. The beacons may be artificial or natural. Operation Two lights are positioned near one another. One, called the front light, is lower than the one behind, which is called the rear light. At night when viewed from a ship, the two lights only become aligned vertically when a vessel is positioned on the correct bearing. During t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delaware River
The Delaware River is a major river in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. From the meeting of its branches in Hancock (village), New York, Hancock, New York, the river flows for along the borders of New York (state), New York, Pennsylvania, New Jersey, and Delaware, before emptying into Delaware Bay. It is the longest free-flowing river in the Eastern United States. The river has been recognized by the National Wildlife Federation as one of the country's Great Waters. The river's drainage basin, watershed drains an area of and provides drinking water for 17 million people. The river has two branches that rise in the Catskill Mountains of New York: the West Branch Delaware River, West Branch at Mount Jefferson (New York), Mount Jefferson in Jefferson, New York, Jefferson, Schoharie County, New York, Schoharie County, and the East Branch Delaware River, East Branch at Grand Gorge, New York, Grand Gorge, Delaware County, New York, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Historic Lighthouse Preservation Act
The National Historic Lighthouse Preservation Act of 2000 (NHLPA; Public Law 106-355; 16 U.S.C. 470w-7) is American legislation creating a process for the transfer of federally owned lighthouses into private hands. It was created as an extension of the National Historic Preservation Act of 1966. Background Maintenance of aids to navigation had been assigned to the federal government from the beginning, first under the Department of the Treasury, and then under the U.S. Lighthouse Board (1852-1910) and its successor, the U.S. Lighthouse Service. In 1939 lighthouses were placed under the authority of the United States Coast Guard, which also took over the manning of lights with keepers. Throughout this period the expense of maintaining and staffing lights was constantly stressed. Automation of lights began early in the twentieth century, and a major push in the early 1960s relieved all but a few lighthouses of their keepers. Lighthouses are fairly high maintenance structures, being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lighthouses Completed In 1918
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 has become uneconomical since the advent of much cheaper, more sophisticated and 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 the 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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lighthouses On The National Register Of Historic Places In Delaware
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 has become uneconomical since the advent of much cheaper, more sophisticated and 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 the 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lighthouses In New Castle County, Delaware
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 has become uneconomical since the advent of much cheaper, more sophisticated and 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 the 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
