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Embrasure
An embrasure (or crenel or crenelle; sometimes called gunhole in the domain of Age of Gunpowder, gunpowder-era architecture) is the opening in a battlement between two raised solid portions (merlons). Alternatively, an embrasure can be a space hollowed out throughout the thickness of a wall by the establishment of a Bay (architecture), bay. This term designates the internal part of this space, relative to the closing device, door or window. In fortification this refers to the outward splay of a window or of an arrowslit on the inside. In ancient and medieval military engineering, embrasures were constructed in towers and walls. A Loophole (firearm), loophole, arrow loop or arrowslit passes through a solid wall, and thus forms an embrasure of shooting, allowing Bow and arrow, archer or Gunner (rank), gunner weapons to be fired out from the fortification while the firer remains under cover. This type of opening was flared inward - that is: the opening was very narrow on the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arrowslit
An arrowslit (often also referred to as an arrow loop, loophole or loop hole, and sometimes a balistraria) is a narrow vertical aperture in a fortification through which an archer can launch arrows or a crossbowman can launch Crossbow bolt, bolts. The interior walls behind an arrow loop are often cut away at an oblique angle so that the archer has a wide field of view and field of fire (weaponry), field of fire. Arrow slits come in a variety of forms. A common one is the cross, accommodating the use of both the longbow and the crossbow. The narrow vertical aperture permits the archer large degrees of freedom to vary the elevation (ballistics), elevation and direction of their bowshot but makes it difficult for attackers to harm the archer since there is only a small target at which to aim. Balistraria, plural ''balistrariae'' (from balister, crossbowman), can often be found in the Curtain wall (fortification), curtain walls of medieval battlements beneath the crenellations. Hist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merlon
A merlon is the solid, upright section of a battlement (a crenellated parapet) in medieval architecture or fortifications. Merlons are sometimes pierced by narrow, vertical embrasures, or tooth-like slits designed for observation and fire. The space between two merlons is called a crenel, and a succession of merlons and crenels is a crenellation. Crenels designed in later eras for use by cannons were also called embrasures. Etymology The term ''merlon'' comes from French 704 adapted from the Italian , possibly a shortened form of , perhaps connected to Latin ("two-pronged pitchfork"), or from a diminutive , from or (a wall). An alternative etymology suggests that the medieval Latin (mentioned from the end of the 10th century) functioned as a diminutive of Latin , " blackbird", expressing an image of this bird sitting on a wall. As part of battlements As an essential part of battlements, merlons were used in fortifications for millennia. The best-known examples appear on m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castle
A castle is a type of fortification, fortified structure built during the Middle Ages predominantly by the nobility or royalty and by Military order (monastic society), military orders. Scholars usually consider a ''castle'' to be the private fortified house, fortified residence of a lord or noble. This is distinct from a mansion, palace, and villa, whose main purpose was exclusively for ''pleasance'' and are not primarily fortresses but may be fortified. Use of the term has varied over time and, sometimes, has also been applied to structures such as hill forts and 19th- and 20th-century homes built to resemble castles. Over the Middle Ages, when genuine castles were built, they took on a great many forms with many different features, although some, such as curtain wall (fortification), curtain walls, arrowslits, and portcullises, were commonplace. European-style castles originated in the 9th and 10th centuries after the fall of the Carolingian Empire, which resulted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battlement
A battlement, in defensive architecture, such as that of city walls or castles, comprises a parapet (a defensive low wall between chest-height and head-height), in which gaps or indentations, which are often rectangular, occur at intervals to allow for the launch of arrows or other projectiles from within the defences. These gaps are termed embrasures, also called crenels or crenelles, and a wall or building with them is described as ; alternative older terms are and . The act of adding crenels to a previously unbroken parapet is termed crenellation. The function of battlements in war is to protect the defenders by giving them part of the parapet to hide behind, from which they can quickly expose themselves to launch projectiles, then retreat behind the parapet. A defensive building might be designed and built with battlements, or a manor house might be fortified by adding battlements, where no parapet previously existed, or cutting crenellations into its existing parape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loophole Closeup Keoti Fort Rewa MP Jan24 A7C 08774
A loophole is an ambiguity or inadequacy in a system, such as a law or security, which can be used to circumvent or otherwise avoid the purpose, implied or explicitly stated, of the system. Originally, the word meant an arrowslit, a narrow vertical window in a wall through which an archer (or, later, gunman) could shoot. Loopholes were commonly used in U.S. forts built during the 1800s. Located in the sally port, a loophole was considered a last ditch defense, where guards could close off the inner and outer doors trapping enemy soldiers and using small arms fire through the slits. Legal loopholes are distinct from lacunae, although the two terms are often used interchangeably. In a loophole, a law addressing a certain issue exists, but can be legally circumvented due to a technical defect in the law, such as a situation where the details are under-specified. A lacuna, on the other hand, is a situation in which no law exists in the first place to address that particular issue. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archimedes
Archimedes of Syracuse ( ; ) was an Ancient Greece, Ancient Greek Greek mathematics, mathematician, physicist, engineer, astronomer, and Invention, inventor from the ancient city of Syracuse, Sicily, Syracuse in History of Greek and Hellenistic Sicily, Sicily. Although few details of his life are known, based on his surviving work, he is considered one of the leading scientists in classical antiquity, and one of the greatest mathematicians of all time. Archimedes anticipated modern calculus and mathematical analysis, analysis by applying the concept of the Cavalieri's principle, infinitesimals and the method of exhaustion to derive and rigorously prove many geometry, geometrical theorem, theorems, including the area of a circle, the surface area and volume of a sphere, the area of an ellipse, the area under a parabola, the volume of a segment of a paraboloid of revolution, the volume of a segment of a hyperboloid of revolution, and the area of a spiral. Archimedes' other math ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Era
Common Era (CE) and Before the Common Era (BCE) are year notations for the Gregorian calendar (and its predecessor, the Julian calendar), the world's most widely used calendar era. Common Era and Before the Common Era are alternatives to the original Anno Domini (AD) and Before Christ (BC) notations used for the same calendar era. The two notation systems are numerically equivalent: " CE" and "AD " each describe the current year; "400 BCE" and "400 BC" are the same year. The expression can be traced back to 1615, when it first appears in a book by Johannes Kepler as the (), and to 1635 in English as " Vulgar Era". The term "Common Era" can be found in English as early as 1708, and became more widely used in the mid-19th century by Jewish religious scholars. Since the late 20th century, BCE and CE have become popular in academic and scientific publications on the grounds that BCE and CE are religiously neutral terms. They have been promoted as more sensitive to non-Christia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polybius
Polybius (; , ; ) was a Greek historian of the middle Hellenistic period. He is noted for his work , a universal history documenting the rise of Rome in the Mediterranean in the third and second centuries BC. It covered the period of 264–146 BC, recording in detail events in Italy, Iberia, Greece, Macedonia, Syria, Egypt and Africa, and documented the Punic Wars and Macedonian Wars among many others. Polybius' ''Histories'' is important not only for being the only Hellenistic historical work to survive in any substantial form, but also for its analysis of constitutional change and the mixed constitution. Polybius' discussion of the separation of powers in government, of checks and balances to limit power, and his introduction of "the people", all influenced Montesquieu's '' The Spirit of the Laws'', John Locke's '' Two Treatises of Government'', and the framers of the United States Constitution. The leading expert on Polybius for nearly a century was F. W. Walbank (1909 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Histories (Polybius)
Polybius' ''Histories'' ( ''Historíai'') were originally written in 40 volumes, only the first five of which are extant in their entirety. The bulk of the work was passed down through collections of excerpts kept in libraries in the Byzantine Empire. Polybius, a historian from the Greek city of Megalopolis in Arcadia, was taken as a hostage to Rome after the Roman victory in the Third Macedonian War (171–168 BC), and there he began to write an account of the rise of Rome to a great power. Publication History Manuscripts Moore (1965) suggests a stemma whereby some 9 prototype manuscripts preserve the manuscript tradition, the oldest being Vaticanus Gr. 124 (dated A.D. 947). Content Polybius' ''Histories'' begin in the year 264 BC and end in 146 BC (Polybius was born around 200 BC and died around 117 BC). He is primarily concerned with the 53 years in which Ancient Rome became a dominant world power. This period, from 220–167 BC, saw Rome subjugate Carthag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannon
A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during the late 19th century. Cannons vary in gauge (firearms), gauge, effective range, mobility (military), mobility, rate of fire, elevation (ballistics), angle of fire and firepower; different forms of cannon combine and balance these attributes in varying degrees, depending on their intended use on the battlefield. A cannon is a type of heavy artillery weapon. The word ''cannon'' is derived from several languages, in which the original definition can usually be translated as ''tube'', ''cane'', or ''reed''. The earliest known depiction of cannons may have appeared in Science and technology of the Song dynasty#Gunpowder warfare, Song dynasty China as early as the 12th century; however, solid archaeological and documentary evidence of cannons do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scorpio (weapon)
The ''scorpio'' or scorpion was a type of Roman torsion siege engine and field artillery piece. It was described in detail by the early-imperial Roman architect and engineer Vitruvius in the 1st century BC and by the 4th century AD officer and historian Ammianus Marcellinus. Ammianus Marcellinus, Roman History' Design Two versions are known: a horizontal two-armed variety like a ballista and a one-armed, vertical version otherwise referred to as an ''onager''. The scorpion was made of a ground frame made of two beams joined together with crossbeams. Spring holes were drilled into the sides of the beams to allow for ropes to be placed in, thus allowing them to serve as sinew-springs. This gave the weapon more power. An arm made of wood known as the ''stilus'', with iron hooks at the end, was used to hold the stone or bolt which was to be fired. The fourth century army officer and historian Ammianus Marcellinus witnessed the use of ''scorpiones'' during several engagements ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firearm
A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and operated by an individual. The term is legally defined further in different countries (see legal definitions). The first firearms originated in 10th-century China, when bamboo tubes containing gunpowder and pellet projectiles were mounted on spears to make the portable fire lance, operable by a single person, which was later used effectively as a shock weapon in the siege of De'an in 1132. In the 13th century, fire lance barrels were replaced with metal tubes and transformed into the metal-barreled hand cannon. The technology gradually spread throughout Eurasia during the 14th century. Older firearms typically used black powder as a propellant, but modern firearms use smokeless powder or other explosive propellants. Most modern firearms (with the notable exception of smoothbore shotguns) have rifled barrels to impart spin to the projectile for improved flight stabili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
