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Chip Log
A chip log, also called common log, ship log, or just log, is a navigation tool sailor, mariners use to estimate the speed of a vessel through water. The word ''knot (unit), knot'', to mean nautical mile per hour, derives from this measurement method. History All nautical instruments that measure the speed of a ship through water are known as logs. This nomenclature dates back to the days of sail, when sailors attached a piece of lumber (a "log" of wood) to a rope knotted at regular intervals off the stern (ship), stern of a ship. Sailors counted the number of knots that passed through their hands in a given time to determine the ship's speed. Today, sailors and aircraft pilots still express speed in knots. Construction A chip log consists of a wooden board attached to a line (the log-line). The log-line has a number of knots at uniform intervals. The log-line is wound on a reel so the user can easily wikt:pay out, pay it out. Over time, log construction standardized. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Log (PSF)
Log most often refers to: * Trunk (botany), the stem and main wooden axis of a tree, called logs when cut ** Logging, cutting down trees for logs ** Firewood, logs used for fuel ** Lumber or timber, converted from wood logs * Logarithm, in mathematics Log, LOG or LoG may also refer to: Arts, entertainment and media * Log (magazine), ''Log'' (magazine), an architectural magazine * ''The Log'', a boating and fishing newspaper published by the Duncan McIntosh Company * Lamb of God (band) or LoG, an American metal band * The Log, an electric guitar by Les Paul * Log, a fictional product in ''The Ren & Stimpy Show'' * The League of Gentlemen or LoG, a British comedy show. Places * Log, Russia, the name of several places * Log, Slovenia, the name of several places Science and mathematics *Logarithm, a mathematical function * Log file, a computer file in which events are recorded * Laplacian of Gaussian or LoG, an algorithm used in digital image processing Other uses * Logbook, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead
Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, 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 nuclide, 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 Amphoterism, amphoteric nature; lead and lead oxides react with acids and base (chemistry), bases, and it tends to form covalent bonds. Lead compounds, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Naval Academy
The United States Naval Academy (USNA, Navy, or Annapolis) is a United States Service academies, federal service academy in Annapolis, Maryland. It was established on 10 October 1845 during the tenure of George Bancroft as United States Secretary of the Navy, Secretary of the Navy. The Naval Academy is the second oldest of the five United States service academies, U.S. service academies and it educates midshipmen for service in the officer corps of the United States Navy and United States Marine Corps. It is part of the Naval University System. The campus is located on the former grounds of Fort Severn at the confluence of the Severn River (Maryland), Severn River and Chesapeake Bay in Anne Arundel County, Maryland, Anne Arundel County, east of Washington, D.C., and southeast of Baltimore. The entire campus, known colloquially as the Yard, is a National Historic Landmark and home to many historic sites, buildings, and monuments. It replaced Philadelphia Naval Asylum in Phila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meter
The metre (or meter in US spelling; symbol: m) is the base unit of length in the International System of Units (SI). Since 2019, the metre has been defined as the length of the path travelled by light in vacuum during a time interval of of a second, where the second is defined by a hyperfine transition frequency of caesium. The metre was originally defined in 1791 by the French National Assembly as one ten-millionth of the distance from the equator to the North Pole along a great circle, so the Earth's polar circumference is approximately . In 1799, the metre was redefined in terms of a prototype metre bar. The bar used was changed in 1889, and in 1960 the metre was redefined in terms of a certain number of wavelengths of a certain emission line of krypton-86. The current definition was adopted in 1983 and modified slightly in 2002 to clarify that the metre is a measure of proper length. From 1983 until 2019, the metre was formally defined as the length of the path t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foot (length)
The foot (standard symbol: ft) is a unit of length in the British imperial and United States customary systems of measurement. The prime symbol, , is commonly used to represent the foot. In both customary and imperial units, one foot comprises 12 inches, and one yard comprises three feet. Since an international agreement in 1959, the foot is defined as equal to exactly 0.3048 meters. Historically, the "foot" was a part of many local systems of units, including the Greek, Roman, Chinese, French, and English systems. It varied in length from country to country, from city to city, and sometimes from trade to trade. Its length was usually between 250 mm and 335 mm and was generally, but not always, subdivided into 12 inches or 16 digits. The United States is the only industrialized country that uses the (international) foot in preference to the meter in its commercial, engineering, and standards activities. The foot is legally recognized in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fathom
A fathom is a unit of length in the imperial and the U.S. customary systems equal to , used especially for measuring the depth of water. The fathom is neither an international standard (SI) unit, nor an internationally accepted non-SI unit. Historically it was the maritime measure of depth in the English-speaking world but, apart from within the US, charts now use metres. There are two yards (6 feet) in an imperial fathom. Originally the span of a man's outstretched arms, the size of a fathom has varied slightly depending on whether it was defined as a thousandth of an (Admiralty) nautical mile or as a multiple of the imperial yard. Formerly, the term was used for any of several units of length varying around . Etymology The term (pronounced ) derives (via Middle English ''fathme'') from the Old English ''fæðm'', which is cognate with the Danish word ''favn'' and means "embracing arms" or "pair of outstretched arms". It is maybe also cognate with the Old High German wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Units Of Measurement
A unit of measurement, or unit of measure, is a definite magnitude (mathematics), magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. Any other quantity of that kind can be expressed as a multiple of the unit of measurement. For example, a length is a physical quantity. The metre (symbol m) is a unit of length that represents a definite predetermined length. For instance, when referencing "10 metres" (or 10 m), what is actually meant is 10 times the definite predetermined length called "metre". The definition, agreement, and practical use of units of measurement have played a crucial role in human endeavour from early ages up to the present. A multitude of System of measurement, systems of units used to be very common. Now there is a global standard, the International System of Units (SI), the modern form of the metric system. In trade, weights and measures are often a su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Bourne (mathematician)
William Bourne (c. 1535–1582) was an English mathematician, innkeeper and former Royal Navy gunner who presented the first design for a navigable submarine and wrote important navigational manuals. He is often called William Bourne of Gravesend. In 1574, he produced a popular version of the Martín Cortés de Albacar's '' Arte de Navegar,'' entitled ''A Regiment for the Sea.'' Bourne was critical of some aspects of the original and produced a manual of more practical use to the seaman. He described how to make observations of the sun and stars, using a cross-staff, and how to plot coastal features from the ship by taking bearings using triangulation.G. L'E. Turner, ‘Bourne, William (c.1535–1582)’, Oxford Dictionary of National Biography, Oxford University Press, 2004. Life in Gravesend Before publishing his submarine design, William Bourne was a jurat in Gravesend, England. His name first appears in the first charter of incorporation of Gravesend from June 5, 1562. Hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailor
A sailor, seaman, mariner, or seafarer is a person who works aboard a watercraft as part of its crew, and may work in any one of a number of different fields that are related to the operation and maintenance of a ship. While the term ''sailor'' has its etymological roots from sailing, that is a time when sailing ships were the main mode of transport at sea, it now refers to the personnel of all watercraft regardless of the type of vessel, boat or ship. It encompasses people who operate ships professionally, be it for a military (navy) or civilian (merchant navy) or for Sailing (sport), sports or recreation. In a navy, there may be further distinctions: ''sailor'' may refer to any member of the navy even if they are based on land, while Seaman (rank), ''seaman'' may refer to a specific enlisted rank. Additionally, fisherman are seen as a distinct type of sailor, that is those engaged in fishing. Sailors have existed from the earliest periods in history as people as people used b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commander W
Commander (commonly abbreviated as Cmdr.) is a common naval officer rank as well as a job title in many armies. Commander is also used as a rank or title in other formal organizations, including several police forces. In several countries, this naval rank is termed as a frigate captain. Commander is also a generic term for an officer commanding any armed forces unit, such as " platoon commander", "brigade commander" and " squadron commander". In the police, terms such as "borough commander" and "incident commander" are used. Commander as a naval and air force rank Commander is a rank used primarily in navies, and is very rarely used as a rank in armies. In most armies, the term "commander" is used as a job title. For example, in the US Army, an officer with the rank of captain ( NATO rank code OF-2) may hold the title of "company commander", whereas an officer with the rank of lieutenant colonel ( NATO rank code OF-4) typically holds the title of "battalion commander". Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hourglass
An hourglass (or sandglass, sand timer, or sand clock) is a device used to measure the passage of time. It comprises two glass bulbs connected vertically by a narrow neck that allows a regulated flow of a substance (historically sand) from the upper bulb to the lower one due to gravity. Typically, the upper and lower bulbs are symmetric as they are usually manufactured by pinching a tube. The specific duration of time a given hourglass measures is determined by factors including the quantity and coarseness of the particulate matter and the neck width. Depictions of an hourglass as a symbol of the passage of time are found in art, especially on tombstones or other monuments, from antiquity to the present day. The form of a winged hourglass has been used as a literal depiction of the Latin phrase ("time flies"). History Antiquity The origin of the hourglass is unclear. Its predecessor the ''clepsydra'', or water clock, is known to have existed in Babylon and Egypt as early ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
