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Fortification Rock
Fortification Rock, once a landmark hill on the Colorado River before it was inundated, now known as Rock Island, southernmost and tallest of the Boulder Islands in Lake Mead, Clark County, Nevada. It has an elevation of 1284 feet. Fortification Rock appears on the 1861 Geological Map No. 1; Rio Colorado of the West, explored by 1st Lieut. Joseph C. Ives, which shows Fortification Rock, Ives Camp #59 and the course of the Colorado River from its mouth on the Gulf of California to Las Vegas Wash and the location of its features and other expedition camps along the way. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CASTELLATED SAND BLUFFS, FORTIFICATION ROCK, COLORADO RIVER - NARA - 524189
A battlement in defensive architecture, such as that of city walls or castles, comprises a parapet (i.e., a defensive low wall between chest-height and head-height), in which gaps or indentations, which are often rectangular, occur at intervals to allow for the launch of arrows or other projectiles from within the defences. These gaps are termed " crenels" (also known as ''carnels'', or ''embrasures''), and a wall or building with them is called crenellated; alternative (older) terms are castellated and embattled. The act of adding crenels to a previously unbroken parapet is termed crenellation. The function of battlements in war is to protect the defenders by giving them something to hide behind, from which they can pop out to launch their own missiles. A defensive building might be designed and built with battlements, or a manor house might be fortified by adding battlements, where no parapet previously existed, or cutting crenellations into its existing parapet wall. A d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1st Lieutenant
First lieutenant is a commissioned officer military rank in many armed forces; in some forces, it is an appointment. The rank of lieutenant has different meanings in different military formations, but in most forces it is sub-divided into a senior (first lieutenant) and junior (second lieutenant) rank. The NATO equivalent rank for land force officers is OF-1 rank. In navies, while certain rank insignia may carry the name lieutenant, the term may also be used to relate to a particular post or duty, rather than a rank. Indonesia In Indonesia, "first lieutenant" is known as ''Letnan Satu'' (''Lettu''), Indonesian National Armed Forces uses this rank across all three of its services. It is just above the rank of second lieutenant and just below the rank of captain. Israel In the Israel Defense Forces, the rank above second lieutenant is simply lieutenant. The rank of (קצין מקצועי אקדמאי (קמ"א (''katsín miktsoí akademai'' or "kama"), a professional academ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landforms Of Clark County, Nevada
A landform is a natural or anthropogenic land feature on the solid surface of the Earth or other planetary body. Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, mountains, canyons, and valleys, as well as shoreline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great ocean basins. Physical characteristics Landforms are categorized by characteristic physical attributes such as elevation, slope, orientation, stratification, rock exposure and soil type. Gross physical features or landforms include intuitive elements such as berms, mounds, hills, ridges, cliffs, valleys, rivers, peninsulas, volcanoes, and numerous other structural and size-scaled (e.g. ponds vs. lakes, hills vs. mountains) elements including various kinds of inland and oceanic waterbodies and sub-surface features. Mountains, hills, plateaux, and plains are the fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fortification
A fortification is a military construction or building designed for the defense of territories in warfare, and is also used to establish rule in a region during peacetime. The term is derived from Latin ''fortis'' ("strong") and ''facere'' ("to make"). From very early history to modern times, defensive walls have often been necessary for cities to survive in an ever-changing world of invasion and conquest. Some settlements in the Indus Valley civilization were the first small cities to be fortified. In ancient Greece, large stone walls had been built in Mycenaean Greece, such as the ancient site of Mycenae (famous for the huge stone blocks of its ' cyclopean' walls). A Greek '' phrourion'' was a fortified collection of buildings used as a military garrison, and is the equivalent of the Roman castellum or English fortress. These constructions mainly served the purpose of a watch tower, to guard certain roads, passes, and borders. Though smaller than a real fortress, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portage
Portage or portaging (Canada: ; ) is the practice of carrying water craft or cargo over land, either around an obstacle in a river, or between two bodies of water. A path where items are regularly carried between bodies of water is also called a ''portage.'' The term comes from French, where means "to carry," as in "portable". In Canada, the term "carrying-place" was sometimes used. Early French explorers in New France and French Louisiana encountered many rapids and cascades. The Native Americans carried their canoes over land to avoid river obstacles. Over time, important portages were sometimes provided with canals with locks, and even portage railways. Primitive portaging generally involves carrying the vessel and its contents across the portage in multiple trips. Small canoes can be portaged by carrying them inverted over one's shoulders and the center strut may be designed in the style of a yoke to facilitate this. Historically, voyageurs often employed tump line ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skiff
A skiff is any of a variety of essentially unrelated styles of small boats. Traditionally, these are coastal craft or river craft used for leisure, as a utility craft, and for fishing, and have a one-person or small crew. Sailing skiffs have developed into high performance competitive classes. Many of today's skiff classes are based in Australia and New Zealand in the form of , , and skiffs. The 29er, 49er, SKUD and Musto Skiff are all considered to have developed from the skiff concept, all of which are sailed internationally. The term skiff is also used for a racing shell called single scull for competitive rowing. Etymology The word is related to ''ship'' and has a complicated etymology: "skiff" comes from the Middle English ''skif'', which derives from the Old French ''esquif'', which in turn derives from the Old Italian ''schifo'', which is itself of Germanic origin (German ''Schiff''). "Ship" comes from the Old English "scip", which has the same Germanic predec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explorer's Rock
Explorer's Rock was a large rock in the Colorado River that was a hazard to navigation at the mouth of the Black Canyon of the Colorado between Arizona and Nevada during the 19th century. It got its name from incident where the iron hulled steamboat ''Explorer'' struck it doing some damage, during the expedition of Lieutenant Joseph C. Ives, Corps of Topographical Engineers to explore the Colorado River of the West in 1857 and 1858. Explorer's Rock, was 4 miles above El Dorado Canyon. This location is just east of Squaw Peaks. History Explorer's Rock located at the entrance to the Black Canyon of the Colorado was one of the significant hazards to navigation to steamboats, barges, and other shipping when ascending or descending the Colorado River between El Dorado Canyon and Callville or Rioville, in the 19th Century. It lay above a short rapid below the mouth of the canyon just below the surface in a reach of still water. Ives describes the circumstances of the collision ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explorer (sternwheeler)
''Explorer'' was a small, custom-made stern-wheel steamboat built for Second lieutenant Joseph Christmas Ives and used by him to carry the U. S. Army Corps of Topographical Engineers expedition to explore the Colorado River above Fort Yuma in 1858. Richard E. Lingenfelter, Steamboats on the Colorado River, 1852-1916, University of Arizona Press, Tucson, 1978 History After inquiring about the cost of chartering one of the Colorado River steamboats of George Alonzo Johnson and findi ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steamboat
A steamboat is a boat that is propelled primarily by steam power, typically driving propellers or paddlewheels. Steamboats sometimes use the prefix designation SS, S.S. or S/S (for 'Screw Steamer') or PS (for 'Paddle Steamer'); however, these designations are most often used for steamships. The term ''steamboat'' is used to refer to smaller, insular, steam-powered boats working on lakes and rivers, particularly riverboats. As using steam became more reliable, steam power became applied to larger, ocean-going vessels. Background Limitations of the Newcomen steam engine Early steamboat designs used Newcomen steam engines. These engines were large, heavy, and produced little power, which resulted in an unfavorable power-to-weight ratio. The Newcomen engine also produced a reciprocating or rocking motion because it was designed for pumping. The piston stroke was caused by a water jet in the steam-filled cylinder, which condensed the steam, creating a vacuum, which in turn caus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Canyon Of The Colorado
The Black Canyon of the Colorado is the canyon on the Colorado River where Hoover Dam was built. The canyon is located on the Colorado River at the state line between Nevada and Arizona. The western wall of the gorge is in the El Dorado Mountains, and the eastern wall is in the Black Mountains of Arizona. The canyon formed about 15 million years ago during the Miocene Basin and Range uplift.Black Canyon Wilderness Area Information on Black Canyon and its natural history. Black Canyon gets its name from the black that are found throughout the area. Just south of the Hoover Dam on the Nevada side of the canyon is the Sauna Cave. This cave was drilled by miners ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colorado River
The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid watershed that encompasses parts of seven U.S. states and two Mexican states. The name Colorado derives from the Spanish language for "colored reddish" due to its heavy silt load. Starting in the central Rocky Mountains of Colorado, it flows generally southwest across the Colorado Plateau and through the Grand Canyon before reaching Lake Mead on the Arizona–Nevada border, where it turns south toward the international border. After entering Mexico, the Colorado approaches the mostly dry Colorado River Delta at the tip of the Gulf of California between Baja California and Sonora. Known for its dramatic canyons, whitewater rapids, and eleven U.S. National Parks, the Colorado River and its tributaries are a vital source of water for 40 million people. An extensive system of dams ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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