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Hooper Island Light
The Hooper Island Light is a lighthouse in the Chesapeake Bay, west of Middle Hooper Island in Maryland. History The initial request of a light at this site was made in 1897, but construction was delayed until 1901 after the Variety Iron Works Company failed to deliver materials in time. Unlike earlier caisson lights in the bay, the foundation was placed using the pneumatic process, in which the caisson is kept under pressure to expel water, and the interior is excavated to bring the cylinder down to the desired depth. The tower is taller than other Maryland sparkplug lights because of the provision for a watch room as well as a lantern atop the tower, the only example in the state. A fog bell was originally housed on the lower gallery but was later moved to the watch room level, a backup to the fog horn added in the 1930s. The characteristic was changed several times through the years, with different patterns of flashes and eclipses. Along with many other Chesapeake Bay lights ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chesapeake Bay
The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic (United States), Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the Eastern Shore of Maryland / Eastern Shore of Virginia and the state of Delaware) with its mouth of the Bay at the south end located between Cape Henry and Cape Charles (headland), Cape Charles. With its northern portion in Maryland and the southern part in Virginia, the Chesapeake Bay is a very important feature for the ecology and economy of those two states, as well as others surrounding within its watershed. More than 150 major rivers and streams flow into the Bay's drainage basin, which covers parts of six states (New York, Pennsylvania, Delaware, Maryland, Virginia and West Virginia) and all of District of Columbia. The Bay is approximately long from its northern headwaters in the Susquehanna River to its outlet in the Atlantic Ocea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caisson (engineering)
In geotechnical engineering, a caisson ( or ; borrowed from French ''caisson'', from Italian ''cassone'', meaning ''large box'', an augmentative of ''cassa'') is a watertight retaining structure used, for example, to work on the foundations of a bridge pier, for the construction of a concrete dam, or for the repair of ships. Caissons are constructed in such a way that the water can be pumped out, keeping the work environment dry. When piers are being built using an open caisson, and it is not practical to reach suitable soil, friction pilings may be driven to form a suitable sub-foundation. These piles are connected by a foundation pad upon which the column pier is erected. Caisson engineering has been used at least since the 18th century, and was notably used in the construction of the Brooklyn Bridge, which was completed in 1883. Types To install a caisson in place, it is brought down through soft mud until a suitable foundation material is encountered. While bedrock is pref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron 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] |
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] |
Maryland
Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to its east. Baltimore is the largest city in the state, and the capital is Annapolis. Among its occasional nicknames are '' Old Line State'', the ''Free State'', and the '' Chesapeake Bay State''. It is named after Henrietta Maria, the French-born queen of England, Scotland, and Ireland, who was known then in England as Mary. Before its coastline was explored by Europeans in the 16th century, Maryland was inhabited by several groups of Native Americans – mostly by Algonquian peoples and, to a lesser degree, Iroquoian and Siouan. As one of the original Thirteen Colonies of England, Maryland was founded by George Calvert, 1st Baron Baltimore, a Catholic convert"George Calvert and Cecilius Calvert, Barons Baltimore" William Hand Browne, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sparkplug Lighthouse
A caisson lighthouse (also referred to as a sparkplug lighthouse, or bug light) is a type of lighthouse whose superstructure rests on a concrete or metal caisson. Caisson lighthouses were developed in the late nineteenth century as a cheaper alternative to screwpile lighthouses. The caisson design was also more efficient as it could better withstand harsh weather, and was not as fragile. Caisson lighthouses usually have living quarters made of cast iron Cast iron is a class of iron–carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impuriti ..., although some brick examples are known. The two American nicknames were later coined because of the structure's shape. Gallery See also References Lighthouses Marine architecture Caissons {{pharology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naval Air Systems Command
The Naval Air Systems Command (NAVAIR) provides materiel support for aircraft and airborne weapon systems for the United States Navy. It is one of the Echelon II Navy systems commands (SYSCOM), and was established in 1966 as the successor to the Navy's Bureau of Naval Weapons. NAVAIR is headquartered in Naval Air Station Patuxent River in St. Mary's County, Maryland, with military and civilian personnel stationed at eight locations across the continental United States and one site overseas. The current commander as of September 2021 is Vice Admiral Carl P. Chebi, USN. The vice commander is Leslie Taylor, SES. The deputy commander is Mr. Theodore J. Short Jr., SES. The Command Master Chief is CMDCM Todd A. Anselm, USN. NAVAIR's mission is to provide full life-cycle support of naval aviation aircraft, weapons and systems operated by Sailors and Marines. This support includes research, design, development and systems engineering, acquisition, test and evaluation, training faciliti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Washington Post
''The Washington Post'' (also known as the ''Post'' and, informally, ''WaPo'') is an American daily newspaper published in Washington, D.C. It is the most widely circulated newspaper within the Washington metropolitan area and has a large national audience. Daily broadsheet editions are printed for D.C., Maryland, and Virginia. The ''Post'' was founded in 1877. In its early years, it went through several owners and struggled both financially and editorially. Financier Eugene Meyer purchased it out of bankruptcy in 1933 and revived its health and reputation, work continued by his successors Katharine and Phil Graham (Meyer's daughter and son-in-law), who bought out several rival publications. The ''Post'' 1971 printing of the Pentagon Papers helped spur opposition to the Vietnam War. Subsequently, in the best-known episode in the newspaper's history, reporters Bob Woodward and Carl Bernstein led the American press's investigation into what became known as the Watergate scandal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Services Administration
The General Services Administration (GSA) is an independent agency of the United States government established in 1949 to help manage and support the basic functioning of federal agencies. GSA supplies products and communications for U.S. government offices, provides transportation and office space to federal employees, and develops government-wide cost-minimizing policies and other management tasks. GSA employs about 12,000 federal workers. It has an annual operating budget of roughly $33 billion and oversees $66 billion of procurement annually. It contributes to the management of about $500 billion in U.S. federal property, divided chiefly among 8,700 owned and leased buildings and a 215,000 vehicle motor pool. Among the real estate assets it manages are the Ronald Reagan Building and International Trade Center in Washington, D.C., which is the largest U.S. federal building after the Pentagon. GSA's business lines include the Federal Acquisition Service (FAS) and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Register Of Historic Places
The National Register of Historic Places (NRHP) is the United States federal government's official list of districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance or "great artistic value". A property listed in the National Register, or located within a National Register Historic District, may qualify for tax incentives derived from the total value of expenses incurred in preserving the property. The passage of the National Historic Preservation Act (NHPA) in 1966 established the National Register and the process for adding properties to it. Of the more than one and a half million properties on the National Register, 95,000 are listed individually. The remainder are contributing resources within historic districts. For most of its history, the National Register has been administered by the National Park Service (NPS), an agency within the U.S. Department of the Interior. Its goals are to help property owners and inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Lighthouse Society
The United States Lighthouse Society is a non-profit organization dedicated to aiding in the restoration of American lighthouses and educating the public about their history. With four chapters, and more than a dozen affiliates, it is one of the largest and oldest lighthouse organizations in the world. History Founded in 1984 by Wayne Wheeler and initially headquartered in San Francisco, California, one of the United States Lighthouse Society's first major projects was the purchase of the lightship LV605 in 1986 from a private individual. The organization subsequently invested $400,000 and more than 40,000 volunteer hours in the preservation and restoration of the vessel. In 2003 the society received the California Governor's Historic Preservation Award for its work on the ship. The society relocated from California to Hansville, Washington in 2008, siting its headquarters at the historic Point No Point Lighthouse, which it rented from Kitsap County (the county, in turn, lease ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
