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Foghorns
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 reed (music), reeds, a similar principle to a modern electric Vehicle horn, car horn. Others used air forced through holes in a rotating cylinder or disk, in the same manner as a siren (alarm), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fog Bell
A fog bell is a navigation mark used as an audible aid to navigation in seafaring, especially in fog and poor visibility. Floating navigation signs with bells are called bell buoys. On ships, the ship's bell is used for sound signals. Due to more suitable sound generators, but also the development and spread of radar, satellite navigation and Electronic Chart Display and Information System, electronic charting systems, fog bells have lost their importance for maritime navigation. Maritime marks on land Starting in the 18th century, fog signals were given for seafaring in Europe, initially with cannons or guns. In 1766, the first bell for this purpose was installed in Nidingen on the Baltic Sea.Thomas Tag''Fog Bells''. United States Lighthouse Society website. Retrieved September 27, 2021. These were initially rung by hand, which was a chore during prolonged fog, others used mechanisms similar to clockwork that had to be wound periodically. Andrew Morse Jr. eventually developed a " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States asserts sovereignty over five Territories of the United States, major island territories and United States Minor Outlying Islands, various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's List of countries and dependencies by area, third-largest land area and List of countries and dependencies by population, third-largest population, exceeding 340 million. Its three Metropolitan statistical areas by population, largest metropolitan areas are New York metropolitan area, New York, Greater Los Angeles, Los Angel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steam
Steam is water vapor, often mixed with air or an aerosol of liquid water droplets. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization. Saturated or superheated steam is invisible; however, wet steam, a visible mist or aerosol of water droplets, is often referred to as "steam". When liquid water becomes steam, it increases in volume by 1,700 times at standard temperature and pressure; this change in volume can be converted into work (physics), mechanical work by steam engines such as reciprocating engine, reciprocating piston type engines and steam turbines, which are a sub-group of steam engines. Piston type steam engines played a central role in the Industrial Revolution and modern steam turbines are used to generate more than 80% of the world's electricity. If liquid water comes in contact with a very hot surface or depressurizes quickly below its vapor pressure, vapour pressure, it can create a steam exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automation
Automation describes a wide range of technologies that reduce human intervention in processes, mainly by predetermining decision criteria, subprocess relationships, and related actions, as well as embodying those predeterminations in machines. Automation has been achieved by various means including Mechanical system, mechanical, hydraulic, pneumatic, electrical, electronic devices, and computers, usually in combination. Complicated systems, such as modern Factory, factories, airplanes, and ships typically use combinations of all of these techniques. The benefit of automation includes labor savings, reducing waste, savings in electricity costs, savings in material costs, and improvements to quality, accuracy, and precision. Automation includes the use of various equipment and control systems such as machinery, processes in factories, boilers, and heat-treating ovens, switching on telephone networks, steering, Stabilizer (ship), stabilization of ships, aircraft and other applic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trinity House Warning Notice
The Trinity (, from 'threefold') is the Christian doctrine concerning the nature of God, which defines one God existing in three, , consubstantial divine persons: God the Father, God the Son (Jesus Christ) and God the Holy Spirit, three distinct persons ('' hypostases'') sharing one essence/substance/nature (''homoousion''). As the Fourth Lateran Council declared, it is the Father who s, the Son who is , and the Holy Spirit who proceeds. In this context, one essence/nature defines God is, while the three persons define God is. This expresses at once their distinction and their indissoluble unity. Thus, the entire process of creation and grace is viewed as a single shared action of the three divine persons, in which each person manifests the attributes unique to them in the Trinity, thereby proving that everything comes "from the Father", "through the Son", and "in the Holy Spirit". This doctrine is called Trinitarianism, and its adherents are called Trinitarians, while i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triangle (musical Instrument)
The triangle, or musical triangle, is a musical instrument in the percussion family, classified as an idiophone in the Hornbostel-Sachs classification system. Triangles are made from a variety of metals including aluminum, beryllium copper, brass, bronze, iron, and steel. The metal is bent into a triangular shape with one open end. The instrument is usually held by a loop of some form of thread or wire at the top curve to enable the triangle to vibrate, and it is struck with a metal rod called a "beater". The triangle theoretically has indefinite pitch, and produces a plurality of overtones when struck with an appropriate beater. History Iconography is the primary source for knowledge of the history of the triangle, and provides insight into the musical and social context in which the instrument developed. Some scholars believe the triangle to be a direct descendant of the ancient Egyptian sistrum. Others do not go quite so far, referring to the triangle as being " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portland Bill
Portland Bill is a narrow promontory (or bill) at the southern end of the Isle of Portland, and the southernmost point of Dorset, England. One of Portland's most popular destinations is Portland Bill Lighthouse. Portland's coast has been notorious for the number of shipwrecked vessels over the centuries. The dangerous coastline features shallow reefs and the Shambles sandbank, made more hazardous due to the strong Portland tidal race. The Bill is an important way-point for coastal traffic, and three lighthouses have been built to protect shipping. The original two worked as a pair from 1716, and they were replaced in 1906 by the current one. History From Roman times, beacon fires were lit to warn ships of the danger of the Bill. A petition to Trinity House was put forward for a lighthouse in the early 18th century, but Trinity House opposed it. They later conceded that a lighthouse was needed and George I granted the patent on 26 May 1716. Trinity House issued a lease to W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrocellulose
Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and sulfuric acid. One of its first major uses was as guncotton, a replacement for gunpowder as propellant in firearms. It was also used to replace gunpowder as a low-order explosive in mining and other applications. In the form of collodion, it was also a critical component in an early photographic emulsion, the use of which revolutionized photography in the 1860s. In the 20th century, it was adapted to automobile lacquer and adhesives. Production The process uses a mixture of nitric acid and sulfuric acid to convert cellulose into nitrocellulose. The quality of the cellulose is important. Hemicellulose, lignin, pentosans, and mineral salts give inferior nitrocelluloses. In organic chemistry, nitrocellulose is a nitrate ester, not a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
