Visual perception is the ability to interpret the surrounding environment using light in the visible spectrum reflected by the objects in the environment. This is different from visual acuity, which refers to how a person sees. A person can have problem with visual perceptual processing if he/she has 20/20 vision; the resulting perception is known as visual perception, sight, or vision. The various physiological components involved in vision are referred to collectively as the visual system, are the focus of much research in linguistics, cognitive science and molecular biology, collectively referred to as vision science; the visual system in animals allows individuals to assimilate information from their surroundings. The act of seeing starts when the cornea and the lens of the eye focuses light from its surroundings onto a light-sensitive membrane in the back of the eye, called the retina; the retina is part of the brain, isolated to serve as a transducer for the conversion of light into neuronal signals.
Based on feedback from the visual system, the lens of the eye adjusts its thickness to focus light on the photoreceptive cells of the retina known as the rods and cones, which detect the photons of light and respond by producing neural impulses. These signals are processed via complex feedforward and feedback processes by different parts of the brain, from the retina upstream to central ganglia in the brain. Note that up until now much of the above paragraph could apply to octopuses, worms and things more primitive. However, the following applies to mammals and birds: The retina in these more complex animals sends fibers to the lateral geniculate nucleus, to the primary and secondary visual cortex of the brain. Signals from the retina can travel directly from the retina to the superior colliculus; the perception of objects and the totality of the visual scene is accomplished by the visual association cortex. The visual association cortex combines all sensory information perceived by the striate cortex which contains thousands of modules that are part of modular neural networks.
The neurons in the striate cortex send axons to the extrastriate cortex, a region in the visual association cortex that surrounds the striate cortex. The human visual system is believed to perceive visible light in the range of wavelengths between 370 and 730 nanometers of the electromagnetic spectrum. However, some research suggests that humans can perceive light in wavelengths down to 340 nanometers the young; the major problem in visual perception is that what people see is not a translation of retinal stimuli. Thus people interested in perception have long struggled to explain what visual processing does to create what is seen. There were two major ancient Greek schools, providing a primitive explanation of how vision is carried out in the body; the first was the "emission theory" which maintained that vision occurs when rays emanate from the eyes and are intercepted by visual objects. If an object was seen directly it was by'means of rays' coming out of the eyes and again falling on the object.
A refracted image was, seen by'means of rays' as well, which came out of the eyes, traversed through the air, after refraction, fell on the visible object, sighted as the result of the movement of the rays from the eye. This theory was championed by scholars like their followers; the second school advocated the so-called'intro-mission' approach which sees vision as coming from something entering the eyes representative of the object. With its main propagators Aristotle and their followers, this theory seems to have some contact with modern theories of what vision is, but it remained only a speculation lacking any experimental foundation. Both schools of thought relied upon the principle that "like is only known by like", thus upon the notion that the eye was composed of some "internal fire" which interacted with the "external fire" of visible light and made vision possible. Plato makes this assertion in his dialogue Timaeus, in his De Sensu. Alhazen carried out many investigations and experiments on visual perception, extended the work of Ptolemy on binocular vision, commented on the anatomical works of Galen.
He was the first person to explain that vision occurs when light bounces on an object and is directed to one's eyes. Leonardo da Vinci is believed to be the first to recognize the special optical qualities of the eye, he wrote "The function of the human eye... was described by a large number of authors in a certain way. But I found it to be different." His main experimental finding was that there is only a distinct and clear vision at the line of sight—the optical line that ends at the fovea. Although he did not use these words he is the father of the modern distinction between foveal and peripheral vision. Issac Newton was the first to discover through experimentation, by isolating individual colors of the spectrum of light passing through a prism, that the visually perceived color of objects appeared due to the character
A prop, formally known as property, is an object used on stage or on screen by actors during a performance or screen production. In practical terms, a prop is considered to be anything movable or portable on a stage or a set, distinct from the actors, scenery and electrical equipment. Consumable food items appearing in the production are considered props; the earliest known use of the term "properties" in English to refer to stage accessories is in the 1425 CE morality play, The Castle of Perseverance. The Oxford English Dictionary finds the first usage of "props" in 1841, while the singular form of "prop" appeared in 1911. During the Renaissance in Europe, small acting troupes functioned as cooperatives, pooling resources and dividing any income. Many performers provided their own costumes, but special items—stage weapons, furniture or other hand-held devices—were considered "company property"; some experts however seem to think that the term comes from the idea that stage or screen objects "belong" to whoever uses them on stage.
There is no difference between props such as theatre, film, or television. Bland Wade, a properties director, says, "A coffee cup onstage is a coffee cup on television, is a coffee cup on the big screen." He adds, "There are different responsibilities and different vocabulary." The term "theatrical property" originated to describe an object used in a stage play and similar entertainments to further the action. Technically, a prop is any object that gives the scenery, actors, or performance space specific period, place, or character; the term comes from live-performance practice theatrical methods, but its modern use extends beyond the traditional plays and musical, novelty and public-speaking performances, to film and electronic media. Props in a production originate from off stage unless they have been preset on the stage before the production begins. Props are stored on a prop table backstage near the actor's entrance during production generally locked in a storage area between performances.
The person in charge of handling the props is called the "props master". Other positions include coordinators, production assistants and interns as may be needed for a specific project; the term has transferred to television, motion picture and video game production, where they are referred to by the phrase movie prop, film prop or prop. In recent years, the increasing popularity of movie memorabilia has added new meaning to the term "prop", broadening its existence to include a valuable after-life as a prized collector's item. Not available until after a film's premiere, movie props appearing on-screen are called "screen-used", can fetch thousands of dollars in online auctions and charity benefits. Many props are ordinary objects. However, a prop must "read well" from the house or on-screen, meaning it must look real to the audience. Many real objects are poorly adapted to the task of looking like themselves to an audience, due to their size, durability, or color under bright lights, so some props are specially designed to look more like the actual item than the real object would look.
In some cases, a prop is designed to behave differently from how the real object would for the sake of safety. Examples of special props are: A prop sack representing a burlap bag, might have another black fabric bag sewn, discreetly inside the burlap, giving it strength, hiding the contents and creating a visual void to the audience view. A prop mop, representing a string mop, but built out of a rectangular shape covered with fabric, so the mop can be slid across the stage to another actress as part of a musical number. A prop weapon that looks functional, but lacks the intentional harmfulness of the corresponding real weapon. In the theater, prop weapons are always either non-operable replicas, or have safety features to ensure they are not dangerous. Guns fire caps or noisy blanks, swords are dulled, knives are made of plastic or rubber. In film production functional weapons are used, but only with special smoke blanks with blank adapted guns instead of real bullets. Real cartridges with bullets removed are still dangerously charged which has caused several tragic instances when used on stage or film.
The safety and proper handling of real weapons used as movie props is the premiere responsibility of the prop master. ATF and other law enforcement agencies may monitor the use of real guns for film and television, but this is not necessary with stage props as these guns are permanently "plugged". Breakaway objects, or stunt props, such as balsa-wood furniture, or sugar glass whose breakage and debris look real but cause injury due to their light weight and weak structure. For such safe props often a stunt double will replace the main actor for shots involving use of breakaway props. Rubber bladed-weapons and guns are examples of props used by stuntmen to minimize injury, or by actors where the action requires a prop which minimizes injury. "Hero" props are the more detailed pieces intended for close inspection by the audience. The hero prop may have legible writing, moving parts, or other attributes or functions missing from a standard prop; the term is used on occasion for any of the items that a main character wou
Claustrophobia is the fear of being in a small space or room and unable to escape or get out. It can be triggered by many situations or stimuli, including elevators crowded to capacity, windowless rooms, hotel rooms with closed doors and sealed windows, small cars and tight-necked clothing, it is classified as an anxiety disorder, which results in panic attacks. The onset of claustrophobia has been attributed to many factors, including a reduction in the size of the amygdala, classical conditioning, or a genetic predisposition to fear small spaces. One study indicates that anywhere from 5–7% of the world population is affected by severe claustrophobia, but only a small percentage of these people receive some kind of treatment for the disorder; the term claustrophobia comes from Latin claustrum "a shut in place" and Greek φόβος, phóbos, "fear". Claustrophobia is thought to have two key symptoms: fear of restriction and fear of suffocation. A typical claustrophobic will fear restriction in at least one, if not several, of the following areas: small rooms, locked rooms, MRI or CAT scan apparatus, buses, trains, underwater caves, cellars and caves.
Additionally, the fear of restriction can cause some claustrophobia to fear trivial matters such as sitting in a barber's chair or waiting in a queue at a shop out of a fear of confinement to a single space. Another possible site for claustrophobic attacks is a dentist's chair during dental surgery; when confined to an area, claustrophobics begin to fear suffocation, believing that there may be a lack of air in the area to which they are confined. Claustrophobia is the fear of having no escape, being closed into a small space, it is classified as an anxiety disorder and times results in a rather severe panic attack. It is confused sometimes with Cleithrophobia; this method was developed in 1979 by interpreting the files of patients diagnosed with claustrophobia and by reading various scientific articles about the diagnosis of the disorder. Once an initial scale was developed, it was sharpened by several experts in the field. Today, it consists of 20 questions that determine anxiety levels and desire to avoid certain situations.
Several studies have proved this scale to be effective in claustrophobia diagnosis. This method was developed by Rachman and Taylor, two experts in the field, in 1993; this method is effective in distinguishing symptoms stemming from fear of suffocation and fear of restriction. In 2001, it was modified from 36 to 24 items by another group of field experts; this study has been proven effective by various studies. One study conducted by University of Wisconsin-Madison's neurology department revealed that anywhere from 5-7% of the world population is affected by severe claustrophobia, but only a small percentage of these people receive some kind of treatment for the disorder; the fears of enclosed spaces is an irrational fear. Most claustrophobic people who find themselves in a room without windows consciously know that they aren't in danger, yet these same people will be afraid terrified to the point of incapacitation, many do not know why; the amygdala is one of the smallest structures in the brain, but one of the most powerful.
The amygdala is needed for the creation of a fight-or-flight response. A fight-or-flight response is created. Cheng believes. In generating a fight-or-flight response, the amygdala acts in the following way: The amygdala's anterior nuclei associated with fear each other. Nuclei send out impulses to other nuclei, which influence respiratory rate, physical arousal, the release of adrenaline, blood pressure, heart rate, behavioral fear response, defensive responses, which may include freezing up; these reactions constitute an'autonomic failure' in a panic attack. A study done by Fumi Hayano found that the right amygdala was smaller in patients who suffered from panic disorders; the reduction of size occurred in a structure known as the corticomedial nuclear group which the CE nucleus belongs to. This causes interference, which in turn causes abnormal reactions to aversive stimuli in those with panic disorders. In claustrophobic people, this translates as panicking or overreacting to a situation in which the person finds themselves physically confined.
Claustrophobia results. It comes as a consequence of a traumatic childhood experience, although the onset can come at any point in an individual's life; such an experience can occur multiple times, or only once, to make a permanent impression on the mind. The majority of claustrophobic participants in an experiment done by Lars-Göran Öst reported that their phobia had been "acquired as a result of a conditioning experience." In most cases, claustrophobia seems to be the result of past experiences. A few examples of common experiences that could result in the onset of claustrophobia in children are as follows: A child is shut into a pitch-black room and cannot find the door or the light-switch. A child gets shut into a box. A child is locked in a closet. A child can not swim. A child gets lost. A child sticks their head between the bars of a fence and cannot get back out. A child gets stuck, or can not find their way back. A child is left in truck, or van. A child is in a crowded area with no windows and h
Clothing is a collective term for items worn on the body. Clothing can be made of animal skin, or other thin sheets of materials put together; the wearing of clothing is restricted to human beings and is a feature of all human societies. The amount and type of clothing worn depend on body type and geographic considerations; some clothing can be gender-specific. Physically, clothing serves many purposes: it can serve as protection from the elements and can enhance safety during hazardous activities such as hiking and cooking, it protects the wearer from rough surfaces, rash-causing plants, insect bites, splinters and prickles by providing a barrier between the skin and the environment. Clothes can insulate against cold or hot conditions, they can provide a hygienic barrier, keeping infectious and toxic materials away from the body. Clothing provides protection from ultraviolet radiation. Wearing clothes is a social norm, being deprived of clothing in front of others may be embarrassing, or not wearing clothes in public such that genitals, breasts or buttocks are visible could be seen as indecent exposure.
There is no easy way to determine when clothing was first developed, but some information has been inferred by studying lice which estimates the introduction of clothing at 42,000–72,000 years ago. The most obvious function of clothing is to improve the comfort of the wearer, by protecting the wearer from the elements. In hot climates, clothing provides protection from sunburn or wind damage, while in cold climates its thermal insulation properties are more important. Shelter reduces the functional need for clothing. For example, hats and other outer layers are removed when entering a warm home if one is living or sleeping there. Clothing has seasonal and regional aspects, so that thinner materials and fewer layers of clothing are worn in warmer regions and seasons than in colder ones. Clothing performs a range of social and cultural functions, such as individual and gender differentiation, social status. In many societies, norms about clothing reflect standards of modesty, religion and social status.
Clothing may function as a form of adornment and an expression of personal taste or style. Clothing can be and has in the past been made from a wide variety of materials. Materials have ranged from leather and furs to woven materials, to elaborate and exotic natural and synthetic fabrics. Not all body coverings are regarded as clothing. Articles carried rather than worn, worn on a single part of the body and removed, worn purely for adornment, or those that serve a function other than protection, are considered accessories rather than clothing, except for shoes. Clothing protects against many things. Clothes protect people from the elements, including rain, snow and other weather, as well as from the sun. However, clothing, too sheer, small, etc. offers less protection. Appropriate clothes can reduce risk during activities such as work or sport; some clothing protects from specific hazards, such as insects, noxious chemicals, weather and contact with abrasive substances. Conversely, clothing may protect the environment from the clothing wearer: for instance doctors wear medical scrubs.
Humans have been ingenious in devising clothing solutions to environmental or other hazards: such as space suits, air conditioned clothing, diving suits, bee-keeper gear, motorcycle leathers, high-visibility clothing, other pieces of protective clothing. Meanwhile, the distinction between clothing and protective equipment is not always clear-cut, since clothes designed to be fashionable have protective value and clothes designed for function consider fashion in their design; the choice of clothes has social implications. They cover parts of the body that social norms require to be covered, act as a form of adornment, serve other social purposes. Someone who lacks the means to procure reasonable clothing due to poverty or affordability, or lack of inclination, is sometimes said to be scruffy, ragged, or shabby. Serious books on clothing and its functions appear from the 19th century as imperialists dealt with new environments such as India and the tropics; some scientific research into the multiple functions of clothing in the first half of the 20th century, with publications such as J.
C. Flügel's Psychology of Clothes in 1930, Newburgh's seminal Physiology of Heat Regulation and The Science of Clothing in 1949. By 1968, the field of environmental physiology had advanced and expanded but the science of clothing in relation to environmental physiology had changed little. There has since been considerable research, the knowledge base has grown but the main concepts remain unchanged, indeed Newburgh's book is still cited by contemporary authors, including those attempting to develop thermoregulatory models of clothing development. In most cultures, gender differentiation of clothing is considered appropriate; the differences are in styles and fabrics. In Western societies, skirts and high-heeled shoes are seen as women's clothing, while neckties are seen as men's clothing. Trousers were once seen as male clothing, but can nowadays be worn by both genders. Male clothes are more practical, but a wider range of clothing styles are available for females. Males are allowed to bare their chests in a greater variety of public places.
Guion Stewart Bluford Jr. Ph. D. is an American aerospace engineer, retired U. S. Air Force officer and fighter pilot, former NASA astronaut, the first African American in space. Before becoming an astronaut, he was an officer in the U. S. Air Force, where he remained while assigned to NASA, rising to the rank of Colonel, he participated in four Space Shuttle flights between 1983 and 1992. In 1983, as a member of the crew of the Orbiter Challenger on the mission STS-8, he became the first African American in space as well as the second person of African ancestry in space, after Cuban cosmonaut Arnaldo Tamayo Méndez. Born in Philadelphia, Bluford graduated from Overbrook High School in 1960, he received a Bachelor of Science degree in Aerospace Engineering from Pennsylvania State University in 1964, a Master of Science degree in Aerospace Engineering from the U. S. Air Force Institute of Technology in 1974, a Doctor of Philosophy degree in Aerospace Engineering with a minor in Laser Physics, again from AFIT, in 1978, a Master of Business Administration degree from the University of Houston–Clear Lake in 1987.
He has attended the Wharton School of Business of the University of Pennsylvania. His hobbies include reading, jogging, handball, scuba diving and golf, he has two sons, Guion III and James. Bluford attended pilot training at Williams Air Force Base, received his pilot wings in January 1966, he went to F-4C combat crew training in Arizona and Florida and was assigned to the 557th Tactical Fighter Squadron, Cam Ranh Bay, Vietnam. He flew 144 combat missions. In July 1967, Bluford was assigned to the 3630th Flying Training Wing, Sheppard Air Force Base, Texas, as a T-38 A instructor pilot, he served as an assistant flight commander. In early 1971, he attended Squadron Officer School and returned as an executive support officer to the Deputy Commander of Operations and as School Secretary for the Wing. In August 1972, Bluford entered the U. S. Air Force Institute of Technology residency school at Ohio. Upon graduating in 1974 with his master's degree, he was assigned to the Air Force Flight Dynamics Laboratory at Wright-Patterson Air Force Base as a staff development engineer.
He served as deputy for advanced concepts for the Aeromechanics Division and as branch chief of the Aerodynamics and Air frame Branch in the Laboratory. He has presented several scientific papers in the area of computational fluid dynamics, he has logged over 5,200 hours of jet flight time in the T-33, T-37, T-38, F-4C, U-2/TR-1, F-5A/B aircraft, including 1,300 hours as a T-38 instructor pilot. He has an FAA commercial pilot license. Bluford was chosen to become a NASA astronaut in August 1979 out of thousands of possible candidates, his technical assignments have included working with Space Station operations, the Remote Manipulator System, Spacelab systems and experiments, Space Shuttle systems, payload safety issues and verifying flight software in the Shuttle Avionics Integration Laboratory and in the Flight Systems Laboratory. Bluford was a mission specialist on STS-8, STS-61-A, STS-39, STS-53. Bluford's first mission was STS-8, which launched from Kennedy Space Center, Florida, on August 30, 1983.
This was the third flight for the Orbiter Challenger and the first mission with a night launch and night landing. During the mission, the STS-8 crew deployed the Indian National Satellite. STS-8 completed 98 orbits of the Earth in 145 hours before landing at Edwards Air Force Base, California, on September 5, 1983. Bluford served on the crew of STS-61-A, the German D-1 Spacelab mission, which launched from Kennedy Space Center on October 30, 1985; this mission was the first to carry eight crew members, the largest crew to fly in space and included three European payload specialists. This was the first dedicated Spacelab mission under the direction of the German Aerospace Research Establishment and the first U. S. mission in which payload. During the mission, the Global Low Orbiting Message Relay Satellite was deployed from a "Getaway Special" container, 76 experiments were performed in Spacelab in such fields as fluid physics, materials processing, life sciences, navigation. After completing 111 orbits of the Earth in 169 hours, Challenger landed at Edwards Air Force Base on November 6, 1985.
Bluford served on the crew of STS-39, which launched from Kennedy Space Center on April 28, 1991, aboard the Orbiter Discovery. The crew gathered aurora, Earth-limb and Shuttle environment data with the AFP-675 payload; this payload consisted of the Cryogenic Infrared Radiance Instrumentation for Shuttle experiment, Far Ultraviolet Camera experiment, the Uniformly Redundant Array, the Quadrupole Ion Neutral Mass Spectrometer, the Horizon Ultraviolet Program experiment. The crew deployed and retrieved the SPAS-II which carried the Infrared Background Signature Survey experiment; the crew operated the Space Test Payload-1 and deployed a classified payload from the Multi-Purpose Experiment Canister
A textile is a flexible material consisting of a network of natural or artificial fibers. Yarn is produced by spinning raw fibres of wool, cotton, hemp, or other materials to produce long strands. Textiles are formed by weaving, crocheting, knotting or tatting, felting, or braiding; the related words "fabric" and "cloth" and "material" are used in textile assembly trades as synonyms for textile. However, there are subtle differences in these terms in specialized usage. A textile is any material made of interlacing fibres, including carpeting and geotextiles. A fabric is a material made through weaving, spreading, crocheting, or bonding that may be used in production of further goods. Cloth may be used synonymously with fabric but is a piece of fabric, processed; the word'textile' is from Latin, from the adjective textilis, meaning'woven', from textus, the past participle of the verb texere,'to weave'. The word'fabric' derives from Latin, most from the Middle French fabrique, or'building, thing made', earlier as the Latin fabrica'workshop.
The word'cloth' derives from the Old English clað, meaning a cloth, woven or felted material to wrap around one, from Proto-Germanic kalithaz. The first clothes, worn at least 70,000 years ago and much earlier, were made of animal skins and helped protect early humans from the ice ages. At some point people learned to weave plant fibers into textiles; the discovery of dyed flax fibres in a cave in the Republic of Georgia dated to 34,000 BCE suggests textile-like materials were made in prehistoric times. The production of textiles is a craft whose speed and scale of production has been altered beyond recognition by industrialization and the introduction of modern manufacturing techniques. However, for the main types of textiles, plain weave, twill, or satin weave, there is little difference between the ancient and modern methods. Textiles have an assortment of uses, the most common of which are for clothing and for containers such as bags and baskets. In the household they are used in carpeting, upholstered furnishings, window shades, coverings for tables and other flat surfaces, in art.
In the workplace they are used in scientific processes such as filtering. Miscellaneous uses include flags, tents, handkerchiefs, cleaning rags, transportation devices such as balloons, kites and parachutes. Textiles are used in many traditional crafts such as sewing and embroidery. Textiles for industrial purposes, chosen for characteristics other than their appearance, are referred to as technical textiles. Technical textiles include textile structures for automotive applications, medical textiles, agrotextiles, protective clothing. In all these applications stringent performance requirements must be met. Woven of threads coated with zinc oxide nanowires, laboratory fabric has been shown capable of "self-powering nanosystems" using vibrations created by everyday actions like wind or body movements. Textiles are made from many materials, with four main sources: animal, plant and synthetic; the first three are natural. In the 20th century, they were supplemented by artificial fibres made from petroleum.
Textiles are made in various strengths and degrees of durability, from the finest microfibre made of strands thinner than one denier to the sturdiest canvas. Textile manufacturing terminology has a wealth of descriptive terms, from light gauze-like gossamer to heavy grosgrain cloth and beyond. Animal textiles are made from hair, skin or silk. Wool refers to the hair of the domestic sheep or goat, distinguished from other types of animal hair in that the individual strands are coated with scales and crimped, the wool as a whole is coated with a wax mixture known as lanolin, waterproof and dirtproof. Woollen refers to a bulkier yarn produced from carded, non-parallel fibre, while worsted refers to a finer yarn spun from longer fibres which have been combed to be parallel. Wool is used for warm clothing. Cashmere, the hair of the Indian cashmere goat, mohair, the hair of the North African angora goat, are types of wool known for their softness. Other animal textiles which are made from hair or fur are alpaca wool, vicuña wool, llama wool, camel hair used in the production of coats, ponchos and other warm coverings.
Angora refers to the long, soft hair of the angora rabbit. Qiviut is the fine inner wool of the muskox. Wadmal is a coarse cloth made of wool, produced in Scandinavia 1000~1500 CE. Sea silk is an fine and valuable fabric, made from the silky filaments or byssus secreted by a gland in the foot of pen shells. Silk is an animal textile made from the fibres of the cocoon of the Chinese silkworm, spun into a smooth fabric prized for its softness. There are two main ty
A hostage is a person, held by one of two belligerent parties to the other or seized as security for the carrying out of an agreement, or as a preventive measure against war. In contemporary usage, it means someone, seized by a criminal abductor in order to compel another party such as a relative, law enforcement, or government to act, or refrain from acting, in a particular way under threat of serious physical harm to the hostage after expiration of an ultimatum. A person who seizes one or more hostages is known as a hostage-taker; the English word "hostage" derives from French ostage, modern otage, from Late Latin obsidaticum, the state of being an obses, "hostage", from Latin obsideō, but an etymological connection was supposed with Latin hostis. This long history of political and military use indicates that political authorities or generals would agree to hand over one or several hostages in the custody of the other side, as guarantee of good faith in the observance of obligations; these obligations would be in the form of signing of a peace treaty, in the hands of the victor, or exchange hostages as mutual assurance in cases such as an armistice.
Major powers, such as Ancient Rome and the British who had colonial vassals, would receive many such political hostages offspring of the elite princes or princesses who were treated according to their rank and put to a subtle long-term use where they would be given an elitist education or even a religious conversion. This would influence them culturally and open the way for an amicable political line if they ascended to power after release; this caused the element gīsl = "hostage" in many old Germanic personal names, thus in placenames derived from personal names, for example Isleworth in west London from Old English Gīslheres wyrð. The practice of taking hostages is ancient, has been used in negotiations with conquered nations, in cases such as surrenders and the like, where the two belligerents depended for its proper carrying out on each other's good faith; the Romans were accustomed to take the sons of tributary princes and educate them at Rome, thus holding a security for the continued loyalty of the conquered nation and instilling a possible future ruler with ideas of Roman civilization.
The practice was commonplace in the Imperial Chinese tributary system between the Han and Tang dynasties. The practice continued through the early Middle Ages; the Irish High King Niall of the Nine Hostages got his epithet Noígiallach because, by taking nine petty kings hostage, he had subjected nine other principalities to his power. This practice was adopted in the early period of the British occupation of India, by France in her relations with the Arab tribes in North Africa; the position of a hostage was that of a prisoner of war, to be retained till the negotiations or treaty obligations were carried out, liable to punishment, to death, in case of treachery or refusal to fulfil the promises made. The practice of taking hostages as security for the carrying out of a treaty between civilized states is now obsolete; the last occasion was at the Treaty of Aix-la-Chapelle, ending the War of the Austrian Succession, when two British peers, Henry Bowes Howard, 11th Earl of Suffolk, Charles, 9th Baron Cathcart, were sent to France as hostages for the restitution of Cape Breton to France.
In France, after the revolution of Prairial, the so-called law of hostages was passed, to meet the royalist insurrection in La Vendée. Relatives of émigrés were taken from disturbed districts and imprisoned, were liable to execution at any attempt to escape. Sequestration of their property and deportation from France followed on the murder of a republican, four to every such murder, with heavy fines on the whole body of hostages; the law only resulted in an increase in the insurrection. Napoleon in 1796 had used similar measures to deal with the insurrection in Lombardy. In times the practice of official war hostages may be said to be confined to either securing the payment of enforced contributions or requisitions in an occupied territory and the obedience to regulations the occupying army may think fit to issue. During the Franco-Prussian War of 1870, the Germans took as hostages the prominent people or officials from towns or districts when making requisitions and when foraging, it was a general practice for the mayor and adjoint of a town which failed to pay a fine imposed upon it to be seized as hostages and retained till the money was paid.
Another case where hostages have been taken in modern warfare has been the subject of much discussion. In 1870 the Germans found it necessary to take special measures to put a stop to train-wrecking by parties in occupied territory not belonging to the recognized armed forces of the enemy, an illegitimate act of war. Prominent citizens were placed on the engine of the train so that it might be understood that in every accident caused by the hostility of the inhabitants their compatriots will be the first to suffer; the measure seems to have been effective. In 1900 during the Second Boer War, by a proclamation issued at Pretoria, Lord Roberts adopted the plan for a similar reason, but shortly afterwards it was abandoned; the Germans between the su