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Osborne Fire Finder
The Osborne Fire Finder is a type of alidade used by fire lookouts to find a directional bearing (azimuth) to smoke in order to alert fire crews to a wildland fire. History and development The forerunner to the device was invented around 1840 by Sir Francis Ronalds to help combat fire in London – he also named his innovation the “Fire Finder”. Ronalds' fire finder comprised a theodolite atop a watchtower. Bearings and vertical angles from the horizon to surrounding features were recorded either on a surrounding cylinder in the form of a panorama or on a circular table at the base of the instrument. The location of any fire could thus be pinpointed even in the dark. The modern version was created by William "W.B." Osborne, a United States Forest Service employee from Portland, Oregon, and has been in service since 1915. Mr. Osborne also designed the photo-recording transit for making panoramic records of forest conditions, as well as a collapsible water-bag knapsack for fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildfire Suppression Equipment
A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a bushfire( in Australia), desert fire, grass fire, hill fire, peat fire, prairie fire, vegetation fire, or veld fire. Some natural forest ecosystems depend on wildfire. Wildfires are distinct from beneficial human usage of wildland fire, called controlled burning, although controlled burns can turn into wildfires. Fossil charcoal indicates that wildfires began soon after the appearance of terrestrial plants approximately 419 million years ago during the Silurian period. Earth's carbon-rich vegetation, seasonally dry climates, atmospheric oxygen, and widespread lightning and volcanic ignitions create favorable conditions for fires. The occurrence of wildfires throughout the history of terrestrial life invites conjecture that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest History Society
The Forest History Society is an American non-profit organization dedicated to the preservation of forest and conservation history."Forest History Society." Echo Project. Center for History and New Media, George Mason University. http://echo.gmu.edu/node/144 The society was established in 1946 and incorporated in 1955. The Forest History Society headquarters in Durham, North Carolina, include the Alvin J. Huss Archives and the Carl A. Weyerhaeuser Library, which combine to provide a comprehensive compilation of materials related to the topic of forest history. The archives house large collections from several national organizations and companies such as the Society of American Foresters, the American Forest and Paper Association, the American Forestry Association, the American Tree Farm System, and the Weyerhaeuser Company as well as many other smaller collections of national and international significance. Additionally, the Forest History Society maintains a publication progr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plane Table
A plane table (plain table prior to 1830) is a device used in surveying site mapping, exploration mapping, coastal navigation mapping, and related disciplines to provide a solid and level surface on which to make field drawings, charts and maps. The early use of the name ''plain table'' reflected its simplicity and plainness rather than its flatness. History The earliest mention of a plane table dates to 1551 in Abel Foullon's ''"Usage et description de l'holomètre"'', published in Paris.Turner, Anthony, ''Early Scientific Instruments, Europe 1400-1800'', Sotheby's Publishing, 1987, . page 81 However, since Foullon's description was of a complete, fully developed instrument, it must have been invented earlier. A brief description was also added to the 1591 edition of Digge's ''Pantometria''. The first mention of the device in English was by Cyprian Lucar in 1590.Turner, Gerard L'E., ''Scientific Instruments 1500-1900, An Introduction'', University of California Press, 1998 . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alidade
An alidade () (archaic forms include alhidade, alhidad, alidad) or a turning board is a device that allows one to sight a distant object and use the line of sight to perform a task. This task can be, for example, to triangulate a scale map on site using a plane table drawing of intersecting lines in the direction of the object from two or more points or to measure the angle and horizontal distance to the object from some reference point's polar measurement. Angles measured can be horizontal, vertical or in any chosen plane. The alidade sighting ruler was originally a part of many types of scientific and astronomical instrument. At one time, some alidades, particularly using circular graduations as on astrolabes, were also called ''diopters''. With modern technology, the name is applied to complete instruments such as the 'plane table alidade'. Origins The word in Arabic ( , "the ruler"), signifies the same device. In Greek and Latin, it is respectively called , "''dioptra''" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Lookout
A fire lookout (partly also called a fire watcher) is a person assigned the duty to look for fire from atop a building known as a fire lookout tower. These towers are used in remote areas, normally on mountain tops with high elevation and a good view of the surrounding terrain, to spot smoke caused by a wildfire. Once a possible fire is spotted, "Smoke Reports", or "Lookout Shots" are relayed to the local Emergency Communications Center (ECC), often by radio or phone. A fire lookout can use a device known as an Osborne Fire Finder to obtain the radial in degrees off the tower, and the estimated distance from the tower to the fire. Part of the lookout's duties include taking weather readings and reporting the findings to the Emergency Communications Center throughout the day. Often several lookouts will overlap in coverage areas and each will “cross” the same smoke, allowing the ECC to use triangulation from the radials to achieve an accurate location of the fire. Onc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Lookout Tower
A fire lookout tower, fire tower or lookout tower, provides housing and protection for a person known as a "fire lookout" whose duty it is to search for wildfires in the wilderness. It is a small building, usually on the summit of a mountain or other high vantage point, to maximize viewing distance and range, known as ''view shed''. From this vantage point the fire lookout can see smoke that may develop, determine the location by using a device known as an ''Osborne Fire Finder'', and call fire suppression personnel to the fire. Lookouts also report weather changes and plot the location of lightning strikes during storms. The location of the strike is monitored for a period of days afterwards, in case of ignition. A typical fire lookout tower consists of a small room, known as a ''cab,'' atop a large steel or wooden tower. Historically, the tops of tall trees have also been used to mount permanent platforms. Sometimes natural rock may be used to create a lower platform. In cases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass Rose
A compass rose, sometimes called a wind rose, rose of the winds or compass star, is a figure on a compass, map, nautical chart, or monument used to display the orientation of the cardinal directions (north, east, south, and west) and their intermediate points. It is also the term for the graduated markings found on the traditional magnetic compass. Today, a form of compass rose is found on, or featured in, almost all navigation systems, including nautical charts, non-directional beacons (NDB), VHF omnidirectional range (VOR) systems, global-positioning systems (GPS), and similar equipment. Types Linguistic anthropological studies have shown that most human communities have four points of cardinal direction. The names given to these directions are usually derived from either locally-specific geographic features (e.g. "towards the hills", "towards the sea") or from celestial bodies (especially the sun) or from atmospheric features (winds, temperature). Most mobile populations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resection (orientation)
Position resection and intersection are methods for determining an unknown geographic position ( position finding) by measuring angles with respect to known positions. In ''resection'', the one point with unknown coordinates is occupied and sightings are taken to the known points; in ''intersection'', the two points with known coordinates are occupied and sightings are taken to the unknown point. Measurements can be made with a compass and topographic map (or nautical chart), theodolite or with a total station using known points of a geodetic network or landmarks of a map. Resection versus intersection Resection and its related method, ''intersection'', are used in surveying as well as in general land navigation (including inshore marine navigation using shore-based landmarks). Both methods involve taking azimuths or bearings to two or more objects, then drawing ''lines of position'' along those recorded bearings or azimuths. When intersecting, lines of position are used to fix th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topographic Map
In modern mapping, a topographic map or topographic sheet is a type of map characterized by large- scale detail and quantitative representation of relief features, usually using contour lines (connecting points of equal elevation), but historically using a variety of methods. Traditional definitions require a topographic map to show both natural and artificial features. A topographic survey is typically based upon a systematic observation and published as a map series, made up of two or more map sheets that combine to form the whole map. A topographic map series uses a common specification that includes the range of cartographic symbols employed, as well as a standard geodetic framework that defines the map projection, coordinate system, ellipsoid and geodetic datum. Official topographic maps also adopt a national grid referencing system. Natural Resources Canada provides this description of topographic maps: Other authors define topographic maps by contrasting them with anot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alidade
An alidade () (archaic forms include alhidade, alhidad, alidad) or a turning board is a device that allows one to sight a distant object and use the line of sight to perform a task. This task can be, for example, to triangulate a scale map on site using a plane table drawing of intersecting lines in the direction of the object from two or more points or to measure the angle and horizontal distance to the object from some reference point's polar measurement. Angles measured can be horizontal, vertical or in any chosen plane. The alidade sighting ruler was originally a part of many types of scientific and astronomical instrument. At one time, some alidades, particularly using circular graduations as on astrolabes, were also called ''diopters''. With modern technology, the name is applied to complete instruments such as the 'plane table alidade'. Origins The word in Arabic ( , "the ruler"), signifies the same device. In Greek and Latin, it is respectively called , "''dioptra''" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
