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Hero Of Byzantium
Hero of Byzantium (or Heron of Byzantium or sometimes Hero the Younger) ( el, Ἥρων) is a name used to refer to the anonymous Byzantine Empire, Byzantine author of two treatises, commonly known as ''Parangelmata Poliorcetica'' and ''Geodesia'', composed in the mid-10th century and found in an 11th-century manuscript in the Vatican Library (Vaticanus graecus 1605). The first is a poliorketikon, an illustrated manual of siegecraft; the second is a work in practical geometry and ballistics, which makes use of locations around Constantinople to illustrate its points. The manuscript consists of 58 folios and 38 colored illustrations. Following a seventh-century defeat by the Arabs in the east and the barbarian powers in the west, the Byzantine Empire found itself gutted of much of its territory and needed to re-establish its military excellence. "Recent research has suggested that the empire first survived, and later expanded, by retaining and adapting military theories and practice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battering Ram
A battering ram is a siege engine that originated in ancient history, ancient times and was designed to break open the masonry walls of fortifications or splinter their wooden gates. In its simplest form, a battering ram is just a large, heavy log carried by several people and propelled with force against an obstacle; the ram would be sufficient to damage the target if the log were massive enough and/or it were moved quickly enough (that is, if it had enough momentum). Later rams encased the log in an arrow-proof, fire-resistant canopy mounted on wheels. Inside the canopy, the log was swung from suspensory chains or ropes. Rams proved effective weapons of war because at the time wall-building materials such as stone and brick were weak in Tension (physics), tension, and therefore prone to cracking when impacted with force. With repeated blows, the cracks would grow steadily until a hole was created. Eventually, a breach would appear in the fabric of the wall, enabling armed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medieval Greek Military Writers
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the Post-classical, post-classical period of World history (field), global history. It began with the fall of the Western Roman Empire and transitioned into the Renaissance and the Age of Discovery. The Middle Ages is the middle period of the three traditional divisions of Western history: classical antiquity, the medieval period, and the modern history, modern period. The medieval period is itself subdivided into the Early Middle Ages, Early, High Middle Ages, High, and Late Middle Ages. Population decline, counterurbanisation, the collapse of centralized authority, invasions, and mass migrations of tribes, which had begun in late antiquity, continued into the Early Middle Ages. The large-scale movements of the Migration Period, including various Germanic peoples, formed new kingdoms in what remained of the Western Roman Empire. In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
10th-century Byzantine Writers
1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. In conventions of sign where zero is considered neither positive nor negative, 1 is the first and smallest positive integer. It is also sometimes considered the first of the infinite sequence of natural numbers, followed by 2, although by other definitions 1 is the second natural number, following 0. The fundamental mathematical property of 1 is to be a multiplicative identity, meaning that any number multiplied by 1 equals the same number. Most if not all properties of 1 can be deduced from this. In advanced mathematics, a multiplicative identity is often denoted 1, even if it is not a number. 1 is by convention not considered a prime number; this was not universally accepted until the mid-20th century. Additionally, 1 is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioptra
A dioptra (sometimes also named dioptre or diopter, from el, διόπτρα) is a classical astronomical and surveying instrument, dating from the 3rd century BC. The dioptra was a sighting tube or, alternatively, a rod with a sight at both ends, attached to a stand. If fitted with protractors, it could be used to measure angles. Use Greek astronomers used the dioptra to measure the positions of stars; both Euclid and Geminus refer to the dioptra in their astronomical works. It continued in use as an effective surveying tool. Adapted to surveying, the dioptra is similar to the theodolite, or surveyor's transit, which dates to the sixteenth century. It is a more accurate version of the groma. There is some speculation that it may have been used to build the Eupalinian aqueduct. Called "one of the greatest engineering achievements of ancient times," it is a tunnel 1,036 meters (4,000 ft) long, "excavated through Mount Kastro on the Greek island of Samos, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geodesy
Geodesy ( ) is the Earth science of accurately measuring and understanding Earth's figure (geometric shape and size), orientation in space, and gravity. The field also incorporates studies of how these properties change over time and equivalent measurements for other planets (known as '' planetary geodesy''). Geodynamical phenomena, including crustal motion, tides and polar motion, can be studied by designing global and national control networks, applying space geodesy and terrestrial geodetic techniques and relying on datums and coordinate systems. The job title is geodesist or geodetic surveyor. History Definition The word geodesy comes from the Ancient Greek word ''geodaisia'' (literally, "division of Earth"). It is primarily concerned with positioning within the temporally varying gravitational field. Geodesy in the German-speaking world is divided into "higher geodesy" ( or ), which is concerned with measuring Earth on the global scale, and "practical geodes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biton (writer)
Biton of Pergamon ( gr, Βίτων) was an ancient Greek writer and engineer, who lived in the second or third century BC. Only two of his works are known: a lost book on optics, entitled ''Optics'', and an extant short treatise on siege machines, ''Construction of War Machines and Catapults'' ( grc, Κατασκευαὶ πολεμικω̑ν ὄργάνων καὶ καταπαλτικω̑ν).Simon Hornblower, "Biton", in Simon Hornblower and Antony Spawforth (eds.), ''The Oxford Classical Dictionary'', 3rd rev. ed. (Oxford University Press, 2005). The Greek may be transliterated ''Kataskeuai polemikon organon kai katapaltikon''. The military treatise is dedicated to a king named Attalus ( grc, Ἄτταλος), evidently a king of Pergamon, either Attalus I (241–197) or Attalus II (159–38). Some scholars have suggested, based on internal evidence, that the text should date to 156–55.Francesco Fiorucci, "Biton of Pergamon", in Roger S. Bagnall, Kai Brodersen, Craige B. Champi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philo Of Byzantium
Philo of Byzantium ( el, , ''Phílōn ho Byzántios'', ca. 280 BC – ca. 220 BC), also known as Philo Mechanicus, was a Greek engineer, physicist and writer on mechanics, who lived during the latter half of the 3rd century BC. Although he was from Byzantium he lived most of his life in Alexandria, Egypt. He was probably younger than Ctesibius, though some place him a century earlier. Life and works Philo was the author of a large work, ''Mechanike syntaxis'' (Compendium of Mechanics), which contained the following sections: * ''Isagoge'' (εἰσαγωγή) – an introduction to mathematics * ''Mochlica'' (μοχλικά) – on general mechanics * ''Limenopoeica'' (λιμενοποιικά) – on harbour building * ''Belopoeica'' (βελοποιικά) – on artillery * ''Pneumatica'' (πνευματικά) – on devices operated by air or water pressure * ''Automatopoeica'' (αὐτοματοποιητικά) – on mechanical toys and diversions * ''Parasceuastica'' ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Athenaeus Mechanicus
Athenaeus Mechanicus is the author of a book on siegecraft, ''On Machines'' ( grc, Περὶ μηχανημάτων '). He is identified by modern scholars with Athenaeus of Seleucia, a member of the Peripatetic school active in the mid-to-late 1st century BC, at Rome and elsewhere.Serafina Cuomo, review of Gatto 2010Bryn Mawr Classical Review 2010.11.35/ref>Duncan B. Campbell, review of Whitehead and Blyth 2004/ref> Life Strabo mentions a contemporary of his, Athenaeus of Seleucia, a Peripatetic philosopher. He was for some time the leading demagogue in his native city, but afterwards came to Rome and became acquainted with Lucius Licinius Varro Murena. On the discovery of the plot which the latter, with Fannius Caepio, had entered into against Augustus, Athenaeus accompanied him in his flight. He was retaken, but pardoned by Augustus, as there was no evidence of his having taken a more active part in the plot. William Smith, ''Dictionary of Greek and Roman Biography and Mythol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boring (manufacturing)
In machining, boring is the process of enlarging a hole that has already been drilled (or cast) by means of a single-point cutting tool (or of a boring head containing several such tools), such as in boring a gun barrel or an engine cylinder. Boring is used to achieve greater accuracy of the diameter of a hole, and can be used to cut a tapered hole. Boring can be viewed as the internal-diameter counterpart to turning, which cuts external diameters. There are various types of boring. The boring bar may be supported on both ends (which only works if the existing hole is a through hole), or it may be supported at one end (which works for both, through holes and blind holes). Lineboring (line boring, line-boring) implies the former. Backboring (back boring, back-boring) is the process of reaching through an existing hole and then boring on the "back" side of the workpiece (relative to the machine headstock). Because of the limitations on tooling design imposed by the fac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auger (drill)
An auger is a device to drill wood or other materials, consisting of a rotating metal shaft with a blade at the end that scrapes or cuts the wood. Types The classical design has a helical screw blade winding around the bottom end of the shaft. The lower edge of the blade is sharpened and scrapes the wood; the rest of the blade lifts the chips out of the way. It is powered with two hands, by a T-shaped handle attached to the top of the shaft. More modern versions have elaborated auger bits with multiple blades in various positions. Modern versions also have different means to drive the shaft, resulting in various tools such as braces, wheel drills (the "eggbeater" drill), and power drills. See also * Augerino The augerino is a legendary creature present in the folk tales of lumberjack and ranching communities in the western United States.Carol Rose, ''Giants, Monsters, and Dragons: An Encyclopedia of Folklore, Legend and Myth''. Norton, 2001, pp. 30- ... * Gimlet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ladder
A ladder is a vertical or inclined set of rungs or steps used for climbing or descending. There are two types: rigid ladders that are self-supporting or that may be leaned against a vertical surface such as a wall, and rollable ladders, such as those made of rope or aluminium, that may be hung from the top. The vertical members of a rigid ladder are called stringers or rails (US) or stiles (UK). Rigid ladders are usually portable, but some types are permanently fixed to a structure, building, or equipment. They are commonly made of metal, wood, or fiberglass, but they have been known to be made of tough plastic. Historical usages Ladders are ancient tools and technology. A ladder is featured in a Mesolithic rock painting that is at least 10,000 years old, depicted in the Spider Caves in Valencia, Spain. The painting depicts two humans using a ladder to reach a wild honeybee nest to harvest honey. The ladder is depicted as long and flexible, possibly made out of some sort of gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
