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Lighthouses On The National Register Of Historic Places In Puerto Rico
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aveiro March 2012-13
Aveiro may refer to: * Aveiro, Pará, a municipality in Brazil * Aveiro, Portugal, a city and municipality in Portugal ** Região de Aveiro, surrounding the city above ** Aveiro District Aveiro District ( pt, Distrito de Aveiro, or ) is located in the central coastal region of Portugal. The capital of the district is the city of Aveiro, which also serves as the seat of Aveiro Municipality. Aveiro District is bordered by the Po ..., surrounding the municipality above ** Roman Catholic Diocese of Aveiro, surrounding the city above ** Aveiro Lagoon (Ria de Aveiro), near the city above *** Aveiro Light, at the entrance to the lagoon above People * Dukes of Aveiro, an aristocratic Portuguese title, granted in 1535 * Cristiano Ronaldo dos Santos Aveiro (born 1985), Portuguese footballer * Kátia Aveiro (born 1977), Portuguese singer * José Aveiro (born 1936), Paraguayan footballer {{disambiguation, geo, surname Portuguese-language surnames ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ostia Antica (archaeological Site)
Ostia Antica ("Ancient Ostia") is a large archaeological site, close to the modern town of Ostia, that is the location of the harbour city of ancient Rome, 25 kilometres (15 miles) southwest of Rome. "Ostia" (plur. of "ostium") is a derivation of "os", the Latin word for "mouth". At the mouth of the River Tiber, Ostia was Rome's seaport, but due to silting the site now lies from the sea. The site is noted for the excellent preservation of its ancient buildings, magnificent frescoes and impressive mosaics. History Origins Ostia may have been Rome's first '' colonia''. According to legend, Ancus Marcius, the fourth king of Rome, was the first to destroy Ficana, an ancient town that was only from Rome and had a small harbour on the Tiber, and then proceeded with establishing the new colony further west and closer to the sea coast. An inscription seems to confirm the establishment of the old ''castrum'' of Ostia in the 7th century BC. The oldest archaeological remains so fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dowels
A dowel is a cylindrical rod, usually made of wood, plastic, or metal. In its original manufactured form, a dowel is called a ''dowel rod''. Dowel rods are often cut into short lengths called dowel pins. Dowels are commonly used as structural reinforcements in cabinet making and in numerous other applications, including: * Furniture shelf supports * Moveable game pieces (i.e. pegs) * Hangers for items such as clothing, key rings, and tools * Wheel axles in toys * Detents in gymnastics grips * Supports for tiered wedding cakes Wood dowel Manufacturing process The traditional tool for making dowels is a ''dowel plate'', an iron (or better, hardened tool steel) plate with a hole having the size of the desired dowel. To make a dowel, a piece of wood is split or whittled to a size slightly bigger than desired and then driven through the hole in the dowel plate. The sharp edges of the hole shear off the excess wood.Ivin SickelsExercises in Wood-Working American Book Compan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dovetail Joint
A dovetail joint or simply dovetail is a joinery technique most commonly used in woodworking joinery (carpentry), including furniture, cabinets, log buildings, and traditional timber framing. Noted for its resistance to being pulled apart (tensile strength), the dovetail joint is commonly used to join the sides of a drawer to the front. A series of 'pins' cut to extend from the end of one board interlock with a series of 'tails' cut into the end of another board. The pins and tails have a trapezoidal shape. Once glued, a wooden dovetail joint requires no mechanical fasteners. History The dovetail joint technique probably pre-dates written history. Some of the earliest known examples of the dovetail joint are in ancient Egyptian furniture entombed with mummies dating from First Dynasty, the tombs of Chinese emperors, and a stone pillar at the Vazhappally Maha Siva Temple in India. The dovetail design is an important method of distinguishing various periods of furniture. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Lime
Hydraulic lime (HL) is a general term for calcium oxide, a variety of lime also called quicklime, that sets by hydration. This contrasts with calcium hydroxide, also called slaked lime or air lime that is used to make lime mortar, the other common type of lime mortar, which sets by carbonation (re-absorbing carbon dioxide (CO2) from the air). Hydraulic lime provides a faster initial set and higher compressive strength than air lime, and hydraulic lime will set in more extreme conditions, including under water. The terms 'hydraulic lime' and 'hydrated lime' are quite similar and may be confused but are not necessarily the same material. Hydrated lime is any lime which has been slaked whether it sets through hydration, carbonation, or both. Calcium reacts in the lime kiln with the clay minerals to produce silicates that enable some of the lime to set through hydration. Any unreacted calcium is slaked to calcium hydroxide which sets through carbonation. These are sometimes called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smeaton's Tower
Smeaton's Tower is a memorial to civil engineer John Smeaton, designer of the third and most notable Eddystone Lighthouse. A major step forward in lighthouse design, Smeaton's structure was in use from 1759 to 1877, until erosion of the ledge it was built upon forced new construction. The tower was largely dismantled and rebuilt on Plymouth Hoe in Plymouth, Devon, where it stands today. History Background England’s coasts are notorious for rough weather, dangerous seas and deathly obstacles. The Eddystone rocks are among them. There were several attempts were made to place a marker on these reefs. The first attempt was called the Winstanley Lighthouse. After it was destroyed in the 1703 storm, a second one called the Rudyard lighthouse was built. This one was also destroyed, this time by a fire in 1755. Born in Austhorpe, Yorkshire, England in 1724, John Smeaton is considered the father of civil engineering. Recognized for his scientific achievements, including the incr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Smeaton
John Smeaton (8 June 1724 – 28 October 1792) was a British civil engineer responsible for the design of bridges, canals, harbours and lighthouses. He was also a capable mechanical engineer and an eminent physicist. Smeaton was the first self-proclaimed "civil engineer", and is often regarded as the "father of civil engineering".Mark Denny (2007). "Ingenium: Five Machines That Changed the World". p. 34. JHU Press. He pioneered the use of hydraulic lime in concrete, using pebbles and powdered brick as aggregate. Smeaton was associated with the Lunar Society. Law and physics Smeaton was born in Austhorpe, Leeds, England. After studying at Leeds Grammar School he joined his father's law firm, but left to become a mathematical instrument maker (working with Henry Hindley), developing, among other instruments, a pyrometer to study material expansion. In 1750, his premises were in the Great Turnstile in Holborn. He was elected a Fellow of the Royal Society in 1753 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civil Engineer
A civil engineer is a person who practices civil engineering – the application of planning, designing, constructing, maintaining, and operating infrastructure while protecting the public and environmental health, as well as improving existing infrastructure that may have been neglected. Civil engineering is one of the oldest engineering disciplines because it deals with constructed environment including planning, designing, and overseeing construction and maintenance of building structures, and facilities, such as roads, railroads, airports, bridges, harbors, channels, dams, irrigation projects, pipelines, power plants, and water and sewage systems. The term "civil engineer" was established by John Smeaton in 1750 to contrast engineers working on civil projects with the military engineers, who worked on armaments and defenses. Over time, various sub-disciplines of civil engineering have become recognized and much of military engineering has been absorbed by civil engineering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Winstanley
Henry Winstanley (31 March 1644 – 27 November 1703) was an English painter, engineer and merchant, who constructed the first Eddystone lighthouse after losing two of his ships on the Eddystone rocks. He died while working on the project during the Great Storm of 1703. Early life and career He was born in Saffron Walden, Essex, and baptised there on 31 March 1644. His father Henry became land steward to the Earl of Suffolk, owner of Audley End House, in 1652, and young Henry also worked at Audley End, first as a porter and then as a secretary. In 1666 Audley End House was bought by Charles II for use as a base when attending Newmarket races, and it became effectively a royal palace. Winstanley developed an interest in engraving after a grand tour of Europe between 1669 and 1674, where he was impressed by Continental architecture and the engravings in which it was portrayed. On his return he is believed to have studied engraving with Wenceslas Hollar, and was employed a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eddystone Lighthouse
The Eddystone Lighthouse is a lighthouse that is located on the dangerous Eddystone Rocks, south of Rame Head in Cornwall, England. The rocks are submerged below the surface of the sea and are composed of Precambrian gneiss. View at 1:50000 scale The current structure is the fourth to be built on the site. The first lighthouse (Winstanley's) was swept away in a powerful storm, killing its architect and five other men in the process. The second (Rudyard's) stood for fifty years before it burned down. The third (Smeaton's) is renowned because of its influence on lighthouse design and its importance in the development of concrete for building; its upper portions were re-erected in Plymouth as a monument. The first lighthouse, completed in 1699, was the world's first open ocean lighthouse, although the Cordouan Lighthouse off the western French coast preceded it as the first offshore lighthouse. The need for a light The Eddystone Rocks are an extensive reef approximately 12 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Channel
The English Channel, "The Sleeve"; nrf, la Maunche, "The Sleeve" (Cotentinais) or ( Jèrriais), (Guernésiais), "The Channel"; br, Mor Breizh, "Sea of Brittany"; cy, Môr Udd, "Lord's Sea"; kw, Mor Bretannek, "British Sea"; nl, Het Kanaal, "The Channel"; german: Ärmelkanal, "Sleeve Channel" ( French: ''la Manche;'' also called the British Channel or simply the Channel) is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busiest shipping area in the world. It is about long and varies in width from at its widest to at its narrowest in the Strait of Dover."English Channel". ''The Columbia Encyclopedia'', 2004. It is the smallest of the shallow seas around the continental shelf of Europe, covering an area of some . The Channel was a key factor in Britain becoming a naval superpower and has been utilised by Britain as a natural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eddystone Rocks
The Eddystone or Eddystone Rocks are a seaswept and eroded group of rocks ranging southwest of Rame Head in Cornwall, England, United Kingdom. Although the nearest point on the mainland to the Eddystone is in Cornwall, the rocks fall within the city limits of Plymouth, and hence within the county of Devon. For centuries the rocks have been a hazard for the ships in the approaches to the English Channel and the port city of Plymouth. There have been four lighthouses on the Eddystone Rocks. Winstanley (two versions; the second replaced the top of the structure), Rudyard, Smeaton and finally the Douglass Lighthouse, which is the present one. When the Douglass Lighthouse was completed, the people of Plymouth paid for the dismantling of the Smeaton Lighthouse from the red rocks of Eddystone and its reassembly at Plymouth Hoe, where it is a popular tourist attraction today. View at 1:50000 scale. The stub of the Smeaton lighthouse still remains on the rocks. In the 1970s, the questi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_(5900530118).jpg "Click for more on -> Ostia Antica (archaeological Site)")
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