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Lizard Lighthouse
The Lizard Lighthouse is a lighthouse at Lizard Point, Cornwall, England, built to guide vessels passing through the English Channel. It was often the welcoming beacon to persons returning to England, where on a clear night, the reflected light could be seen away. History A light was first exhibited here in 1619, built thanks to the efforts of Sir Christopher Dimaline but it was extinguished and the tower demolished in 1630 because of difficulties in raising funds for its operation and maintenance. The current lighthouse, consisting of two towers with cottages between them, was built in 1751 by the landowner Thomas Fonnereau; each tower was topped by a coal-fired brazier. Trinity House took responsibility for the installation in 1771. In 1812 the coal burners on each tower were replaced with Argand lamps and reflectors. In each tower a fixed arrangement of nineteen lamps and reflectors was installed. In 1873 the original lamps and reflectors were still in use. That year, be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lizard Point, Cornwall
Lizard Point () in Cornwall is at the southern tip of the Lizard Peninsula. It is situated half-a-mile (800 m) south of Lizard village in the civil parish of Landewednack and about 11 miles (18 km) southeast of Helston. Lizard Point is the most southerly point on mainland Great Britain at 49° 57' 30" N. With the exception of parts of the Isles of Scilly, it is the southernmost part of England and the wider United Kingdom. History and geography Lizard Point is for many ships the starting point of their ocean passage and a well known shipping hazard. The Lizard Lighthouse is situated at Lizard Point. Immediately below the lighthouse, situated in what used to be a hotel, is the YHA Lizard Youth Hostel. Lizard Point is situated within '' Caerthillian to Kennack SSSI'' (Site of Special Scientific Interest), noted for its biological and geological interest. Polpeor Cove is a small cove to the east of Lizard Point. The area is famous for its carved serpentine items, w ... [...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] |
Transformer
A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer's core, which induces a varying electromotive force (EMF) across any other coils wound around the same core. Electrical energy can be transferred between separate coils without a metallic (conductive) connection between the two circuits. Faraday's law of induction, discovered in 1831, describes the induced voltage effect in any coil due to a changing magnetic flux encircled by the coil. Transformers are used to change AC voltage levels, such transformers being termed step-up or step-down type to increase or decrease voltage level, respectively. Transformers can also be used to provide galvanic isolation between circuits as well as to couple stages of signal-processing circuits. Since the invention of the first constant-potential transfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automatic Lamp Changer
An automatic lamp changer (or lampchanger) is a device used to ensure that a navigational light such as a marine lighthouse or aero beacon stays lit even if a bulb burns out. Numerous types exist. The common design elements are an array of two or more lamps (or bulbs), installed on a mounting which can rotate to various positions. Each position brings a different lamp into the focal point of an optical assembly. Since signal and navigational lights use sophisticated optics to focus the beam, lampchangers are designed to position the new bulb at the focal point with high precision. The device automatically detects when the currently active lamp has ceased to function and moves the next lamp into place. History The automatic lampchanger was invented by Charles Wallace and patented in 1928. This original model held two headlight lamps from a Model T automobile. The United States Lighthouse Service The United States Lighthouse Service, also known as the Bureau of Lighthouses, was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Electric Company
The General Electric Company (GEC) was a major British industrial conglomerate involved in consumer and defence electronics, communications, and engineering. The company was founded in 1886, was Britain's largest private employer with over 250,000 employees in the 1980s, and at its peak in the 1990s, made profits of over £1 billion a year. In June 1998, GEC sold its share of the joint venture GEC-Alsthom on the Paris stock exchange. In December 1999, GEC's defence arm, Marconi Electronic Systems, was sold to British Aerospace, forming BAE Systems. The rest of GEC, mainly telecommunications equipment manufacturing, continued as Marconi Communications. After buying several US telecoms manufacturers at the top of the market, losses following the bursting of the dot-com bubble in 2001 led to the restructuring in 2003 of Marconi plc into Marconi Corporation plc. In 2005, Ericsson acquired the bulk of that company. What was left of the business was renamed Telent. History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filament Lamp
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 less ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Arc Lamp
An arc lamp or arc light is a lamp that produces light by an electric arc (also called a voltaic arc). The carbon arc light, which consists of an arc between carbon electrodes in air, invented by Humphry Davy in the first decade of the 1800s, was the first practical electric light. It was widely used starting in the 1870s for street and large building lighting until it was superseded by the incandescent light in the early 20th century. It continued in use in more specialized applications where a high intensity point light source was needed, such as searchlights and movie projectors until after World War II. The carbon arc lamp is now obsolete for most of these purposes, but it is still used as a source of high intensity ultraviolet light. The term is now used for gas discharge lamps, which produce light by an arc between metal electrodes through a gas in a glass bulb. The common fluorescent lamp is a low-pressure mercury arc lamp. The xenon arc lamp, which produces a high ... [...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] |
Foghorn
A foghorn or fog signal is a device that uses sound to warn vehicles of navigational hazards such as rocky coastlines, or boats of the presence of other vessels, in foggy conditions. The term is most often used in relation to marine transport. When visual navigation aids such as lighthouses are obscured, foghorns provide an audible warning of rock outcrops, shoals, headlands, or other dangers to shipping. Description All foghorns use a vibrating column of air to create an audible tone, but the method of setting up this vibration differs. Some horns, such as the Daboll trumpet, used vibrating plates or metal reeds, a similar principle to a modern electric car horn. Others used air forced through holes in a rotating cylinder or disk, in the same manner as a siren. Semi-automatic operation of foghorns was achieved by using a clockwork mechanism (or "coder") to sequentially open the valves admitting air to the horns; each horn was given its own timing characteristics to help marine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hornsby-Akroyd Oil Engine
The Hornsby-Akroyd oil engine, named after its inventor Herbert Akroyd Stuart and the manufacturer Richard Hornsby & Sons, was the first successful design of an internal combustion engine using heavy oil as a fuel. It was the first to use a separate vapourising combustion chamber and is the forerunner of all hot-bulb engines, which are considered predecessors of the similar Diesel engine, developed a few years later. Early internal combustion engines were quite successful running on gaseous and light petroleum fuels. However, due to the dangerous nature of petroleum and light petroleum fuel, legal restrictions were placed on their transportation and storage. Heavier petroleum fuels, such as kerosene, were quite prevalent, as they were used for lighting, but posed specific problems when used in internal combustion engines: Oil used for engine fuel must be turned to a vapour state and remain in that state during compression. Furthermore, the combustion of the fuel must be powerf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Hornsby & Sons
Richard Hornsby & Sons was an engine and machinery manufacturer in Grantham, Lincolnshire, England from 1828 until 1918. The company was a pioneer in the manufacture of the oil engine developed by Herbert Akroyd Stuart, which was marketed under the ''Hornsby-Akroyd'' name. The company developed an early track system for vehicles, selling the patent to Holt & Co. (predecessor to Caterpillar Inc.) in America. In 1918, Richard Hornsby & Sons became a subsidiary of the neighbouring engineering firm Rustons of Lincoln, to create Ruston & Hornsby. Formation The company took the name of Richard Hornsby (1790–1864), an agricultural engineer. The company was founded when Hornsby opened a blacksmith's in Grantham, Lincolnshire, in 1815 with Richard Seaman, after joining Seaman's business in 1810. The company became Richard Hornsby & Sons in 1828, when Hornsby bought out his partner's ownership, when Seaman retired. Product range and inventions Agricultural machinery Richard Horn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magneto
A magneto is an electrical generator that uses permanent magnets to produce periodic pulses of alternating current. Unlike a dynamo, a magneto does not contain a commutator to produce direct current. It is categorized as a form of alternator, although it is usually considered distinct from most other alternators, which use field coils rather than permanent magnets. Hand-cranked magneto generators were used to provide ringing current in telephone systems. Magnetos were also adapted to produce pulses of high voltage in the ignition systems of some gasoline-powered internal combustion engines to provide power to the spark plugs. Use of such ignition magnetos for ignition is now limited mainly to engines without a low-voltage electrical system, such as lawnmowers and chainsaws, and to aircraft engines, in which keeping the ignition independent of the rest of the electrical system ensures that the engine continues running in the event of alternator or battery failure. For redundancy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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