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Crémaillère
A crémaillère is a French, mechanical term for the rack, or a straight bar with teeth on one edge designed to work into the teeth of a wheel or a pinion (French pignon) that predates the Renaissance. The term was generally applied in English to engineering applications which had notched, toothed or drilled surface, even when only visually so, such as the edge of the staircase. The term is also applied to the rack railway. During the 17th to 19th centuries the term was widely applied to lines of entrenchment that are usually formed in a saw-tooth pattern, known as indented lines, particularly during sieges. These lines are usually employed on banks of rivers, or on ground which is more elevated than, or which commands, that of the enemy. The defense of these lines is sometimes strengthened by double redans, and flat bastions constructed at intervals, along their front. During the American Civil War, the Confederate States Army used such defenses in Centerville, Virginia in 1862, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rack Railway
A rack railway (also rack-and-pinion railway, cog railway, or cogwheel railway) is a steep grade railway with a toothed rack and pinion, rack rail, usually between the running Track (rail transport)#Rail, rails. The trains are fitted with one or more gear, cog wheels or pinions that mesh with this rack rail. This allows the trains to operate on steep grades above 10%, which is the maximum for Adhesion railway, friction-based rail. Most rack railways are mountain railways, although a few are Rapid transit, transit railways or tramways built to overcome a steep Grade (slope), gradient in an Urban area, urban environment. The first cog railway was the Middleton Railway between Middleton, Leeds, Middleton and Leeds in West Yorkshire, England, United Kingdom, where the first commercially successful steam locomotive, ''Salamanca (locomotive), Salamanca'', ran in 1812. This used a rack and pinion system designed and patented in 1811 by John Blenkinsop. The first mountain cog railway was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fort C
A fortification is a military construction or building designed for the defense of territories in warfare, and is also used to establish rule in a region during peacetime. The term is derived from Latin ''fortis'' ("strong") and ''facere'' ("to make"). From very early history to modern times, defensive walls have often been necessary for cities to survive in an ever-changing world of invasion and conquest. Some settlements in the Indus Valley civilization were the first small cities to be fortified. In ancient Greece, large stone walls had been built in Mycenaean Greece, such as the ancient site of Mycenae (famous for the huge stone blocks of its ' cyclopean' walls). A Greek '' phrourion'' was a fortified collection of buildings used as a military garrison, and is the equivalent of the Roman castellum or English fortress. These constructions mainly served the purpose of a watch tower, to guard certain roads, passes, and borders. Though smaller than a real fortress, they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Terminology
Military terminology refers to the terms and language of military organizations and personnel as belonging to a discrete category. As distinguishable by their usage in military doctrine, they serve to depoliticise, dehumanise, or otherwise abstract discussion about its operations from an actual description thereof. Common understanding The operational pressure for uniform understanding has developed since the early 20th century with the importance of joint operations between different services (army, navy, air force) of the same country. International alliances and operations, including peacekeeping, have added additional complexity. For example, the NATO alliance now maintains a large dictionary of common terms for use by member countries. Development work is also taking place between NATO and Russia on common terminology for extended air defence, in English, French and Russian. Criticism Some claim military terms serve to depoliticise, dehumanize, or otherwise abstract di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surgical Instrument
A surgical instrument is a tool or device for performing specific actions or carrying out desired effects during a surgery or operation, such as modifying biological tissue, or to provide access for viewing it. Over time, many different kinds of surgical instruments and tools have been invented. Some surgical instruments are designed for general use in all sorts of surgeries, while others are designed for only certain specialties or specific procedures. Classification of surgical instruments helps surgeons to understand the functions and purposes of the instruments. With the goal of optimizing surgical results and performing more difficult operations, more instruments continue to be invented in the modern era. History Many different kinds of surgical instruments and tools have been invented and some have been repurposed as medical knowledge and surgical practices have developed. As surgery practice diversified, some tools are advanced for higher accuracy and stability while so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enfilade Fire
Enfilade and defilade are concepts in military tactics used to describe a military formation's exposure to enemy fire. A formation or position is "in enfilade" if weapon fire can be directed along its longest axis. A unit or position is "in defilade" if it uses natural or artificial obstacles to shield or conceal itself from enfilade and hostile fire. The strategies, named by the English during the Hundred Years' War, use the French '' enfiler'' ("to put on a string or sling") and ''défiler'' ("to slip away or off") spoken by English nobility of the time. Enfilade fire—gunfire directed against an enfiladed formation or position—is also commonly known as "flanking fire". Raking fire is the equivalent term in naval warfare. Strafing, firing on targets from a flying platform, is often done with enfilade fire. It is a very advantageous, and much sought for, position for the attacking force. Enfilade A formation or position is "in enfilade" if weapon fire can be directed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Fire
Direct fire or line-of-sight fire refers to firing of a ranged weapon whose projectile is launched directly at a target within the line-of-sight of the user. The firing weapon must have a sighting device and an unobstructed view to the target, which means no obstacles or friendly units can be between it and the target. A weapon engaged in direct fire conversely exposes itself to direct return fire from the target.p.49, Bailey This is in contrast to indirect fire, which refers to firing a projectile on a curved ballistic trajectory or delivering self-accelerated munitions capable of long range and various degrees of homing abilities to alter the flight path. Indirect fire does not need a direct line-of-sight to the target because the shots are normally directed by a forward observer. As such, indirect-fire weapons can shoot over obstacles or friendly units and the weapons can be concealed from counter-battery fire. Description Examples of direct-fire weapons include most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oblique Fire
Oblique may refer to: * an alternative name for the character usually called a slash (punctuation) ( / ) *Oblique angle, in geometry *Oblique triangle, in geometry *Oblique lattice, in geometry * Oblique leaf base, a characteristic shape of the base of a leaf *''Oblique angle'', a synonym for Dutch angle, a cinematographic technique * ''Oblique'' (album), by jazz vibraphonist Bobby Hutcherson * ''Oblique'' (film), a 2008 Norwegian film * ''Oblique'' (Vasarely), a 1966 collage, by Victor Vasarely *Oblique banded rattail, a fish also known as a rough-head whiptail *Oblique case, in linguistics * Oblique argument, in linguistics *Oblique correction, in particle physics *Oblique motion, in music *Oblique order, a military formation *Oblique projection, in geometry and drawing, including cavalier and cabinet projection *Oblique reflection, in Euclidean geometry *Oblique shock, in gas dynamics *Oblique type, in typography *Oblique wing, in aircraft design *Oblique icebreaker, a special ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indented Battery
__FORCETOC__ In the written form of many languages, an indentation or indent is an empty space at the beginning of a line to signal the start of a new paragraph. Many computer languages have adopted this technique to designate "paragraphs" or other logical blocks in the program. For example, the following lines are indented, using between one and six spaces: This paragraph is indented by 1 space. This paragraph is indented by 3 spaces. This paragraph is indented by 6 spaces. In computer programming, the neologisms outdent, unindent and dedent are used to describe the reversal of the indentation process, realigning text with the page margin (or with previous, lesser, levels of indentation). In right-to-left languages (e.g. Hebrew and Arabic), indentation is used just the same, but from the right margin of the paper, where the line begins. Indentation in typesetting There are three main types of indentation, illustr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artillery
Artillery is a class of heavy military ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, and led to heavy, fairly immobile siege engines. As technology improved, lighter, more mobile field artillery cannons developed for battlefield use. This development continues today; modern self-propelled artillery vehicles are highly mobile weapons of great versatility generally providing the largest share of an army's total firepower. Originally, the word "artillery" referred to any group of soldiers primarily armed with some form of manufactured weapon or armor. Since the introduction of gunpowder and cannon, "artillery" has largely meant cannons, and in contemporary usage, usually refers to shell-firing guns, howitzers, and mortars (collectively called ''barrel artillery'', ''cannon artillery'', ''gun artillery'', or - a lay ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arlington County, Virginia
Arlington County is a county in the Commonwealth of Virginia. The county is situated in Northern Virginia on the southwestern bank of the Potomac River directly across from the District of Columbia, of which it was once a part. The county is coextensive with the U.S. Census Bureau's census-designated place of Arlington. Arlington County is considered to be the second-largest " principal city" of the Washington metropolitan area, although Arlington County does not have the legal designation of independent city or incorporated town under Virginia state law. In 2020, the county's population was estimated at 238,643, making Arlington the sixth-largest county in Virginia by population; if it were incorporated as a city, Arlington would be the third most populous city in the state. With a land area of , Arlington is the geographically smallest self-governing county in the U.S., and by reason of state law regarding population density, it has no incorporated towns within its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Union Army
During the American Civil War, the Union Army, also known as the Federal Army and the Northern Army, referring to the United States Army, was the land force that fought to preserve the Union of the collective states. It proved essential to the preservation of the United States as a working, viable republic. The Union Army was made up of the permanent regular army of the United States, but further fortified, augmented, and strengthened by the many temporary units of dedicated volunteers, as well as including those who were drafted in to service as conscripts. To this end, the Union Army fought and ultimately triumphed over the efforts of the Confederate States Army in the American Civil War. Over the course of the war, 2,128,948 men enlisted in the Union Army, including 178,895 colored troops; 25% of the white men who served were immigrants, and further 25% were first generation Americans.McPherson, pp.36–37. Of these soldiers, 596,670 were killed, wounded or went missi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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