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Berry Head Lighthouse
Berry Head Lighthouse is an active lighthouse, located at the end of Berry Head near Brixham in Devon, which has been in operation since 4 May 1906. Berry Head is reputedly the shortest lighthouse in Great Britain, but also one of the highest, being only tall, but above mean sea level. It was also said to be the ''deepest'' because the optic was originally turned by a weight falling down a deep shaft. History The lighthouse was designed and built for Trinity House by its chief engineer Thomas Matthews. When first lit, the incandescent lamp was fuelled by oil gas (which was purchased from the Great Western Railway at Exeter and stored in large external tanks on site). The lamp was placed within a revolving third-order dioptric optic, which gave a double white flash every 15 seconds. It had a range of . Berry Head was classed as an unwatched light; it was managed by an attendant, who brought it into service each evening. In addition, the clockwork mechanism which turned th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brixham
Brixham is a coastal town and civil parish, the smallest and southernmost of the three main population centres (the others being Paignton and Torquay) on the coast of Torbay in the county of Devon, in the south-west of England. Commercial fishing and tourism are the two main industries. As of 2020 Brixham had an estimated population of 16,823. It is believed that the name Brixham originates from the personal name of an early resident, Brioc, followed by the Old English suffix, ''ham'' meaning home. The town, which is predominantly hilly, is built around a picturesque natural harbour, which in addition to leisure craft, provides anchorage for what is now one of England’s (but not the UK’s) largest remaining commercial fishing fleets. A conspicuous local tourist attraction is the permanently moored replica of Sir Francis Drake's ship ''Golden Hind''. Historically Brixham was made up of two separate communities connected only by a marshy lane. In Fishtown, in the immediate v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioptric
Dioptrics is the branch of optics dealing with refraction, similarly the branch dealing with mirrors is known as catoptrics. Dioptrics is the study of the refraction of light, especially by lenses. Telescopes that create their image with an objective that is a convex lens ( 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 father of modern optics. See also * Diopter/Dioptre (unit of measurement) * Dioptrice (work by Johannes Kepler) * Catoptrics (study of and optical systems utilizing reflection) * Catadioptrics (study of and optical systems utilizing reflection and refraction) * Optical telescope * List of telescope types * Image-forming optical system In optics, an image-forming optical system is a system capable of being used for imaging. The diame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lighthouses In Devon
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 Completed In 1906
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 ree ... [...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 England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Characteristic
A light characteristic is all of the properties that make a particular navigational light identifiable. Graphical and textual descriptions of navigational light sequences and colours are displayed on nautical charts and in Light Lists with the chart symbol for a lighthouse, lightvessel, buoy or sea mark with a light on it. Different lights use different colours, frequencies and light patterns, so mariners can identify which light they are seeing. Abbreviations While light characteristics can be described in prose, e.g. "Flashing white every three seconds", lists of lights and navigation chart annotations use abbreviations. The abbreviation notation is slightly different from one light list to another, with dots added or removed, but it usually follows a pattern similar to the following (see the chart to the right for examples). * An abbreviation of the type of light, e.g. "Fl." for flashing, "F." for fixed. * The color of the light, e.g. "W" for white, "G" for green, "R" for re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sun Valve
A sun valve (''Swedish: solventil'', "solar valve") is a flow control valve that automatically shuts off gas flow during daylight. It earned its inventor Gustaf Dalén the 1912 Nobel Prize in Physics. Subsequently other variants of sun valve were developed for various different uses. Dalén's valve The valve was the key component of the Dalén light used in lighthouses from the 1900s through the 1960s, by which time electric lighting was dominant. Prominent engineers, such as Thomas Edison, doubted that the device could work. The German patent office required a demonstration before approving the patent application. Design The valve is controlled by four metal rods enclosed in a glass tube. The central rod that is blackened is surrounded by the three polished rods. As sunlight falls onto all of the rods, the absorbed heat of the sun expands the dark rod, switching a valve to cut the gas supply. After sunset, the central rod cools down, contracting to become the same length ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylene
Acetylene ( systematic name: ethyne) is the chemical compound with the formula and structure . It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in its pure form and thus is usually handled as a solution. Pure acetylene is odorless, but commercial grades usually have a marked odor due to impurities such as divinyl sulfide and phosphine.Compressed Gas Association (1995Material Safety and Data Sheet – Acetylene As an alkyne, acetylene is unsaturated because its two carbon atoms are bonded together in a triple bond. The carbon–carbon triple bond places all four atoms in the same straight line, with CCH bond angles of 180°. Discovery Acetylene was discovered in 1836 by Edmund Davy, who identified it as a "new carburet of hydrogen". It was an accidental discovery while attempting to isolate potassium metal. By heating potassium carbonate with carbon at very high temperatures, he pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AGA AB
AGA AB, previously ''AB Gasaccumulator'' and ''AB Svenska Gasaccumulator'', was a Swedish industrial gas company founded in 1904. Nobel Prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfre ... laureate Gustaf Dalén was instrumental in the success of the company. Important inventions included the AGA cooker and the Dalén light. In the 1990s AGA conceived and developed HiQ for specialty gases. In 2000, AGA was integrated into Linde AG. References External links * * Linde GasHiQ Specialty Gases from AGA and The Linde Group Defunct companies of Sweden Linde plc {{industry-company-stub ... [...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 len ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devon
Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devon is a coastal county with cliffs and sandy beaches. Home to the largest open space in southern England, Dartmoor (), the county is predominately rural and has a relatively low population density for an English county. The county is bordered by Somerset to the north east, Dorset to the east, and Cornwall to the west. The county is split into the non-metropolitan districts of East Devon, Mid Devon, North Devon, South Hams, Teignbridge, Torridge, West Devon, Exeter, and the unitary authority areas of Plymouth, and Torbay. Combined as a ceremonial county, Devon's area is and its population is about 1.2 million. Devon derives its name from Dumnonia (the shift from ''m'' to ''v'' is a typical Celtic consonant shift). During ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
