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Burnham-on-Sea Low Lighthouse
The Low Lighthouse is one of three historic lighthouses in Burnham-on-Sea, Somerset, England, and the only one of the three which is still active. It is a Grade II listed building and stands on the foreshore. First lit in 1832, the Low Lighthouse operated in conjunction with the (onshore) High Lighthouse for 137 years. Then, in 1969 (after improvements had been made to the High Lighthouse) the Low Lighthouse was deactivated; but later, in 1993, the Low Lighthouse was re-established and the High Lighthouse was instead decommissioned). The Low Lighthouse has long been known as 'the Lighthouse on Legs', as evident in an 1859 guide book: "the writer has heard merry children, while sporting on the sands, call this smaller beacon, ''the lighthouse on legs''". Location Burnham-on-Sea is notable for its beach and mudflats, which are characteristic of Bridgwater Bay and the rest of the Bristol Channel where the tide can recede for over . Burnham is close to the estuary of the River ... [...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] |
Lighthouses Completed In 1832
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] |
List Of Lighthouses In England
This is a list of lighthouses in England. It includes lighthouses which are no longer in use as a light but are still standing. It also includes some of the harbour and pier-head lights around the country. Details of several lighthouses and lightvessels in current use in England, together with Wales, the Channel Islands and Gibraltar can be found on the website of Trinity House. Locations of major lighthouses are shown on the adjacent map. __TOC__ Active lighthouses Inactive lighthouses See also *Lists of lighthouses *List of lighthouses in Wales *List of lighthouses in Scotland *List of lighthouses in the Isle of Man *List of lighthouses in Ireland *List of lighthouses in the Channel Islands Notes References External links * see Lighthouses of the British IsleslighthousesRus.org (England Page)* {{Architecture of England England Lighthouses Lighthouses A lighthouse is a tower, building, or other type of physical structure designed to emit light from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedgemoor
Sedgemoor is a low-lying area of land in Somerset, England. It lies close to sea level south of the Polden Hills, historically largely marsh (or "moor" in its older sense). The eastern part is known as King's Sedgemoor, and the western part West Sedgemoor. Sedgemoor is part of the area now known as the Somerset Levels and Moors. Historically the area was known as the site of the Battle of Sedgemoor. Sedgemoor has given its name to a local government district formed on 1 April 1974, under the Local Government Act 1972, by a merger of the municipal borough of Bridgwater, the Burnham-on-Sea urban district, Bridgwater Rural District and part of Axbridge Rural District. The district covers a larger area than the historical Sedgemoor, extending north of the Polden Hills across the Somerset Levels and Moors to the Mendip Hills. On 1 April 2023 the district will be abolished and replaced by a new unitary district for the area at present served by Somerset County Council. The ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Focal Plane
In Gaussian optics, the cardinal points consist of three pairs of points located on the optical axis of a rotationally symmetric, focal, optical system. These are the '' focal points'', the principal points, and the nodal points. For ''ideal'' systems, the basic imaging properties such as image size, location, and orientation are completely determined by the locations of the cardinal points; in fact only four points are necessary: the focal points and either the principal or nodal points. The only ideal system that has been achieved in practice is the plane mirror, however the cardinal points are widely used to ''approximate'' the behavior of real optical systems. Cardinal points provide a way to analytically simplify a system with many components, allowing the imaging characteristics of the system to be approximately determined with simple calculations. Explanation The cardinal points lie on the optical axis of the optical system. Each point is defined by the effect the opti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sector Light
A sector light is a man-made pilotage and position fixing aid that consists of strictly delineated horizontal angle light beams to guide water-borne traffic through a safe channel at night in reasonable visibility. Sector lights are most often used for safe passage through shallow or dangerous waters. This may be when leaving or entering harbour. Nautical charts (paper and electronic) give all the required information. Sectors of colored glass (or plastic) are placed in the lanterns of these lights. The light will then show these colors when observed certain bearings. Bearings referring to a sector are given in degrees true, as observed from sea. Though the colors of the light will change, the characteristics will not. The change of color is not abrupt. The transition is made through an arc of uncertainty of 2° or greater. The colors that are used, are conform to the IALA Maritime Buoyage system that is designed by the International Association of Lighthouse Authorities: * whit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioptric
Dioptrics is the branch of optics dealing with refraction, similarly the branch dealing with mirror A mirror or looking glass is an object that Reflection (physics), reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the ...s is known as catoptrics. Dioptrics is the study of the refraction of light, especially by lens (optics), lenses. Optical telescope, Telescopes that create their image with an Objective (optics), objective that is a Lens (optics)#Types of simple lenses, convex lens (Refracting telescope, refractors) are said to be "dioptric" telescopes. An early study of dioptrics was conducted by Ptolemy in relationship to the human eye as well as refraction in media such as water. The understanding of the principles of dioptrics was further expanded by Alhazen, considered the List of people known as the father or mother of something, father of mode ... [...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] |
Submarine Cable
Submarine cable is any electrical cable that is laid on the seabed, although the term is often extended to encompass cables laid on the bottom of large freshwater bodies of water. Examples include: *Submarine communications cable *Submarine power cable A submarine power cable is a transmission cable for carrying electric power below the surface of the water. fi:Merikaapeli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerosene Lamp
A kerosene lamp (also known as a paraffin lamp in some countries) is a type of lighting device that uses kerosene as a fuel. Kerosene lamps have a wick or mantle as light source, protected by a glass chimney or globe; lamps may be used on a table, or hand-held lanterns may be used for portable lighting. Like oil lamps, they are useful for lighting without electricity, such as in regions without rural electrification, in electrified areas during power outages, at campsites, and on boats. There are three types of kerosene lamp: flat-wick, central-draught (tubular round wick), and mantle lamp. Kerosene lanterns meant for portable use have a flat wick and are made in dead-flame, hot-blast, and cold-blast variants. Pressurized kerosene lamps use a gas mantle; these are known as Petromax, Tilley lamps, or Coleman lamps, among other manufacturers. They produce more light per unit of fuel than wick-type lamps, but are more complex and expensive in construction and more complex to o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incandescent Light Bulb
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxidation. Current is supplied to the filament by terminals or wires embedded in the glass. A bulb socket provides mechanical support and electrical connections. Incandescent bulbs are manufactured in a wide range of sizes, light output, and voltage ratings, from 1.5 volts to about 300 volts. They require no external regulating equipment, have low manufacturing costs, and work equally well on either alternating current or direct current. As a result, the incandescent bulb became widely used in household and commercial lighting, for portable lighting such as table lamps, car headlamps, and flashlights, and for decorative and advertising lighting. Incandescent bulbs are much less efficient than other types of electric lighting, converting les ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
