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Plumb Line
A plumb bob, plumb bob level, or plummet, is a weight, usually with a pointed tip on the bottom, suspended from a string and used as a vertical direction as a reference line, or plumb-line. It is a precursor to the spirit level and used to establish a vertical datum. It is typically made of stone, wood, or lead, but can also be made of other metals. If it is used for decoration, it may be made of bone or ivory. The instrument has been used since at least the time of ancient EgyptDenys A. Stocks. Experiments in Egyptian archaeology: stoneworking technology in Ancient Egypt'. Routledge; 2003. . p. 180. to ensure that constructions are " plumb", or vertical. It is also used in surveying, to establish the nadir (opposite of zenith) with respect to gravity of a point in space. It is used with a variety of instruments (including levels, theodolites, and steel tapes) to set the instrument exactly over a fixed survey marker or to transcribe positions onto the ground for placin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plumbum
Lead () is a chemical element; it has symbol Pb (from Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its amphoteric nature; lead and lead oxides react with acids and bases, and it tends to form covalent bonds. Compounds of lead are usually found in the +2 oxidation state rather than the +4 state common with lighter members of the carbon group. Exceptions are mostly limited to organolead compounds. Like the lighter members of the group, lead tends to bond with itself; it can form chains and polyhedral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A-frame
An A-frame is a basic structure designed to bear a Structural load, load in a lightweight economical manner. The simplest form of an A-frame is two similarly sized Beam (structure), beams, arranged in an angle of 45 degrees or less, attached at the top, like an uppercase letter 'A'. These materials are often wooden or steel beams attached at the top by rope, welding, Adhesive, gluing, or riveting. A-frames can be used as-is, as part of Shear legs, shears, or set up in a row along a longitudinal beam for added stability, as in a saw horse. More complex structures will often have crossmembers connecting the A-frames at different angles,"A-frame" (2009). ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0). Oxford University Press. forming a truss. Other structures that use A-frames * A-frame house * A-frame hydroponics system * A-frame contour measuring spirit level * A frame camping tent * A-frame complex, a motif in chemistry * Folding ladder * Double wishbone susp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archipendulum
The archipendulum is an ancient ancestor of the spirit level and astrolabe, and was used to check whether a line was horizontal or at a desired inclination. It consisted of a handheld A-shaped construction with a plumbline suspended from the top vertex. The horizontal bar of the A was marked at its midpoint, so that the plumbline's coincidence with this point indicated that the bases of the two legs were at the same level. Other gradations on the horizontal bar enabled the user to construct or verify inclined lines. The same methods of use apply to the inverted 'T' which is simply another variant of the archipendulum. Used by the builders of the Egyptian pyramids and from the Indian subcontinent, it was more recently described by Johann Heinrich Alsted and Leon Battista Alberti Leon Battista Alberti (; 14 February 1404 – 25 April 1472) was an Italian Renaissance humanist author, artist, architect, poet, Catholic priest, priest, linguistics, linguist, philosopher, and crypt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Egypt
Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower Egypt were amalgamated by Menes, who is believed by the majority of List of Egyptologists, Egyptologists to have been the same person as Narmer. The history of ancient Egypt unfolded as a series of stable kingdoms interspersed by the "Periodization of ancient Egypt, Intermediate Periods" of relative instability. These stable kingdoms existed in one of three periods: the Old Kingdom of Egypt, Old Kingdom of the Early Bronze Age; the Middle Kingdom of Egypt, Middle Kingdom of the Middle Bronze Age; or the New Kingdom of Egypt, New Kingdom of the Late Bronze Age. The pinnacle of ancient Egyptian power was achieved during the New Kingdom, which extended its rule to much of Nubia and a considerable portion of the Levant. After this period, Egypt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclinometer
An inclinometer or clinometer is an measuring instrument, instrument used for measuring angles of slope, elevation, or depression (geology), depression of an object with respect to gravity's direction. It is also known as a ''tilt indicator'', ''tilt sensor'', tiltmeter, ''tilt meter'', ''slope alert'', ''slope gauge'', ''gradient meter'', ''gradiometer'', ''level gauge'', ''level meter'', ''declinometer'', and ''pitch & roll indicator''. Clinometers measure both inclines and declines using three different units of measure: degree (angle), degrees, percentage points, and topos. The Astrolabes, astrolabe is an example of an inclinometer that was used for celestial navigation and location of astronomical objects from ancient history, ancient times to the Renaissance. A ''tilt sensor'' can measure the wikt:tilt, tilting in often two axes of a reference plane in two axes. In contrast, a full motion would use at least three axes and often additional sensors. One way to measure tilt a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plumb Bob With String
Plumb may refer to: Arts and entertainment * ''Plumb'', a 1995 album by Jonatha Brooke & The Story * ''Plumb'' (Plumb album), 1997 * ''Plumb'' (Field Music album), 2012 * ''Plumb'' (novel series), 1978–1983 novel series by Maurice Gee * , by Romanian poet George Bacovia People * Plumb (surname) * Plumb (singer), stage name of American singer-songwriter Tiffany Arbuckle Lee (born 1975) Places in the United States * Plumb Beach, Brooklyn, New York City, New York, a beach and neighborhood * Plumb Branch, Missouri, a stream * Plumb Brook, New York Tools * Plumb bob, a type of tool * Plumb (tools), a brand of tools known for its hammers Other uses * Plumb Lane, an arterial road in Reno, Nevada * Plumb Memorial Library, a historic public library in Shelton, Connecticut See also * Plumb House (other) * Plumbing Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses piping, pipes, valves, piping and plumbing fitting, plu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lot Hg
Lot, LOT, The Lot or similar may refer to: Common meanings Areas *Land lot, an area of land *Parking lot, for automobiles *Backlot, in movie production Sets of items *A great many of something, as in, "There are a lot of beetles," or "There are lots of beetles." *Lot number, in batch production *Lot, a set of goods for sale together in an auction; or a quantity of a financial instrument Chance *Sortition (drawing lots) **Cleromancy, divination by casting lots **Arabian lots, or Arabic parts, an astrological divination technique People *Lot (name), including a list of people with the given name *Lot (biblical person), figure in the Book of Genesis *King Lot, in Arthurian legend Places * Lot, Belgium, a village in the municipality of Beersel *Lot (department), in southwest France *Lot (river), in southern France * Lostock railway station, Bolton, England * Lewis University Airport, Illinois, US * The Lot, or Samuel Goldwyn Studio, Hollywood, California, US Arts and media Film ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tower
A tower is a tall Nonbuilding structure, structure, taller than it is wide, often by a significant factor. Towers are distinguished from guyed mast, masts by their lack of guy-wires and are therefore, along with tall buildings, self-supporting structures. Towers are specifically distinguished from buildings in that they are built not to be habitable but to serve other functions using the height of the tower. For example, the height of a clock tower improves the visibility of the clock, and the height of a tower in a fortified building such as a castle increases the visibility of the surroundings for defensive purposes. Towers may also be built for observation tower, observation, leisure, or telecommunication purposes. A tower can stand alone or be supported by adjacent buildings, or it may be a feature on top of a larger structure or building. Etymology Old English ''torr'' is from Latin ''turris'' via Old French ''tor''. The Latin term together with Greek language, Greek τύ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domes
A dome () is an architectural element similar to the hollow upper half of a sphere. There is significant overlap with the term cupola, which may also refer to a dome or a structure on top of a dome. The precise definition of a dome has been a matter of controversy and there are a wide variety of forms and specialized terms to describe them. A dome can rest directly upon a rotunda wall, a drum, or a system of squinches or pendentives used to accommodate the transition in shape from a rectangular or square space to the round or polygonal base of the dome. The dome's apex may be closed or may be open in the form of an oculus, which may itself be covered with a roof lantern and cupola. Domes have a long architectural lineage that extends back into prehistory. Domes were built in ancient Mesopotamia, and they have been found in Persian, Hellenistic, Roman, and Chinese architecture in the ancient world, as well as among a number of indigenous building traditions throughout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spire
A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires are typically made of stonework or brickwork, or else of timber structures with metal cladding, ceramic tiling, roof shingles, or slates on the exterior. Since towers supporting spires are usually square, square-plan spires emerge directly from the tower's walls, but octagonal spires are either built above a pyramidal transition section called a '' broach'' at the spire's base, or else free spaces around the tower's summit for decorative elements like pinnacles. The former solution is known as a ''broach spire''. Small or short spires are known as ''spikes'', ''spirelets'', or '' flèches''. Etymology This sense of the word spire is attested in English since the 1590s, ''spir'' having been used in Middle Low German since the 14t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Datum
Data ( , ) are a collection of discrete or continuous value (semiotics), values that convey information, describing the quantity, qualitative property, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpretation (logic), interpreted formally. A datum is an individual value in a collection of data. Data are usually organized into structures such as table (information), tables that provide additional context and meaning, and may themselves be used as data in larger structures. Data may be Data (computer science), used as variable (research), variables in a computational process. Data may represent abstract ideas or concrete measurements. Data are commonly used in scientific research, economics, and virtually every other form of human organizational activity. Examples of data sets include price indices (such as the consumer price index), unemployment rates, literacy rates, and census data. In this context, data repr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
