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table |
top 10 words in brain distribution (in article): time type state form century require term world provide refer |
top 10 words in brain distribution (in article): century term people plate style type design popular word modern |
top 10 words in brain distribution (not in article): light produce plant drink lamp card fruit water music wine |
top 10 words in brain distribution (not in article): state city wear horse house build cross store Unite head |
times more probable under arch 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under table (words not in the model) | |
An arch'" is a structure that spans a space while supporting weight (e.g. a doorway in a stone wall). Arches appeared as early as the 2nd millennium BC in Mesopotamian brick architecture, but their systematic use started with the Ancient Romans who were the first to apply the technique to a wide range of structures. History. Arches were known by the Mesopotamian, Urartian, Harappan, Egyptian, Babylonian, Greek and Assyrian civilizations, but their use was infrequent and mostly confined to underground structures such as drains where the problem of lateral thrust is greatly diminished. The ancient Romans learned the arch from the Etruscans, refined it and were the first builders to tap its full potential for above ground buildings: "The Romans were the first builders in Europe, perhaps the first in the world, fully to appreciate the advantages of the arch, the vault and the dome." Throughout the Roman empire, their engineers erected arch structures such as bridges, aqueducts, and gates. They also introduced the triumphal arch as a military monument. Vaults began to be used for roofing large interior spaces such as halls and temples, a function which was also assumed by domed structures from the 1st century BC onwards. The Roman arch is semicircular, and built from an odd number of arch bricks (called "voussoirs"). An odd number of bricks is required for there to be a "capstone" or "keystone", the topmost stone in the arch. The Roman arch's shape is the simplest to build, but not the strongest. There is a tendency for the sides to bulge outwards, which must be counteracted by an added weight of masonry to push them inwards. The Romans used this type of semicircular arch freely in many of their secular structures such as aqueducts, palaces and amphitheaters. The semicircular arch was followed in Europe by the pointed Gothic arch or ogive (derived from the Islamic pointed arch in Moorish Spain), whose centreline more closely followed the forces of compression and which was therefore stronger. The semicircular arch can be flattened to make an elliptical arch as in the Ponte Santa Trinita. The parabolic and catenary arches are now known to be the theoretically strongest forms. Parabolic arches were introduced in construction by the Spanish architect Antoni Gaudí, who admired the structural system of Gothic style, but for the buttresses, which he termed “architectural crutches”. The catenary and parabolic arches carry all horizontal thrust to the foundation and so do not need additional elements. The horseshoe arch is based on the semicircular arch, but its lower ends are extended further round the circle until they start to converge. The first examples known are carved into rock in India in the first century AD, while the first known built horseshoe arches are known from Aksum (modern day Ethiopia and Eritrea) from around the 3rd–4th century, around the same time as the earliest contemporary examples in Syria, suggesting either an Aksumite or Syrian origin for the type of arch. It was used in Spanish Visigothic architecture, Islamic architecture and mudéjar architecture, as in the Great Mosque of Damascus and in later Moorish buildings. It was used for decoration rather than for strength. Across the ocean in Mexico and Central America, Mesoamerican civilizations created various types of corbelled arches, such as with the interior tunnels in the Great Pyramid of Cholula and the many styles of corbelled arches built by the Mayan civilization. In Peru, the Inca civilization used a trapezoidal arch in their architecture. The arch is still used today in some modern structures such as bridges. Construction. An arch requires all of its elements to hold it together, raising the question of how an arch is constructed. One answer is to build a frame (historically, of wood) which exactly follows the form of the underside of the arch. This is known as a centre or centring. The voussoirs are laid on it until the arch is complete and self-supporting. For an arch higher than head height, scaffolding would in any case be required by the builders, so the scaffolding can be combined with the arch support. Occasionally arches would fall down when the frame | A table'" is a item of furniture comprising a surface supported by a base or legs. It may be used to hold articles such as food at a convenient or comfortable height when sitting, and is therefore often used in conjunction with chairs. Unlike many earlier table designs, most modern tables do not have drawers, although they are not uncommon. A table specifically intended for writing and office work is a desk, which may incorporate one or more drawers in the base. Some tables have removable sections or "leaves" used to extend the surface, or utilise hinged extensions of the table top known as "drop leaves". Etymology. The term "table" is derived from a merger of French "table" and Old English "tabele", ultimately from the Latin word "tabula", "a board, plank, flat top piece". In Late Latin, "tabula" took over the meaning previously reserved to "mensa" (preserved in Spanish "mesa" "table"). In Old English, the word replaced "bord" for this meaning. Shape, height, and function. Tables come in a wide variety of shapes, height, and materials, depending on their origin, style, and intended use. All tables are composed of a flat surface and a base with one or more supports, or legs. A table with a single, central foot is a pedestal table. Tables can be freestanding or designed for placement against a wall (a console table). Table tops can be in virtually any shape, although rectangular, square, round (e.g., the round table), and oval tops are the most frequent. Long tables often have extra legs for support. Others have higher surfaces for personal use while either standing or sitting on a tall stool. Many tables have tops that can be adjusted to change their position or size, either with foldable extensions or sliding parts that can alter the shape of the top. Some tables are entirely foldable for easy transport, e.g., camping. Small tables in trains and aircraft may be fixed or foldable, although many are simply convenient shelves rather than tables. Types of table. Tables of various shapes and sizes are designed for specific uses: Historically, various types of tables have been popular for other uses: History. Some very early tables were made and used by the Egyptians, and were little more than metal or stone platforms used to keep objects off the floor. They were not used for seating people. Food was put on large plates deposed on a pedestal for eating. The Egyptians made use of various small tables and elevated playing boards. The Chinese also created very early tables in order to pursue the arts of writing and painting. The Greeks and Romans made more frequent use of tables, notably for eating, although Greek tables were pushed under a bed after use. The Greeks invented a piece of furniture very similar to the guéridon. Tables were made of marble or wood and metal (typically bronze or silver alloys). Later, the larger rectangular tables were made of separate platforms and pillars. The Romans also introduced a large, semicircular table to Italy, the "mensa lunata". Furniture during the Middle Ages is not as well-known as that of earlier or later periods, and most sources show the types used by the nobility. In the Eastern Roman Empire, tables were made of metal or wood, usually with four feet and frequently linked by x-shaped stretchers. Tables for eating were large and often round or semicircular. A combination of a small round table and a lectern seemed very popular as a writing table. In western Europe, the invasions and internecine wars caused most of the knowledge inherited from the classical era to be lost. As a result of the necessary movability, most tables were simple trestle tables, although small round tables made from joinery reappeared during the 15th century and onward. In the Gothic era, the chest (furniture) became widespread and was often used as a table. Refectory tables first appeared at least as early as the 16th century, as an evolution of the trestle table; these tables were typically quite long and capable of supporting a sizeable banquet in the great hall or other reception room of a castle. |