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Flint Stone
Flint, occasionally flintstone, is a sedimentary rock, sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Flint was widely used historically to make stone tools and fire making, start fires. It occurs chiefly as nodule (geology), nodules and masses in sedimentary rocks, such as chalks and limestones.''The Flints from Portsdown Hill'' Inside the nodule, flint is usually dark grey, black, green, white or brown in colour, and often has a glassy or waxy appearance. A thin layer on the outside of the nodules is usually different in colour, typically white and rough in texture. The nodules can often be found along streams and beaches. Flint breaks and chips into sharp-edged pieces, making it useful for knife blades and other cutting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenomanian
The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name. As a unit of geologic time measure, the Cenomanian Age spans the time between 100.5 and 93.9 million years ago (Mya). In the geologic timescale, it is preceded by the Albian and is followed by the Turonian. The Upper Cenomanian starts around at 95 Mya. The Cenomanian is coeval with the Woodbinian of the regional timescale of the Gulf of Mexico and the early part of the Eaglefordian of the regional timescale of the East Coast of the United States. At the end of the Cenomanian, an anoxic event took place, called the Cenomanian-Turonian boundary event or the "Bonarelli event", that is associated with a minor extinction event for marine spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beach
A beach is a landform alongside a body of water which consists of loose particles. The particles composing a beach are typically made from rock, such as sand, gravel, shingle, pebbles, etc., or biological sources, such as mollusc shells or coralline algae. Sediments settle in different densities and structures, depending on the local wave action and weather, creating different textures, colors and gradients or layers of material. Though some beaches form on inland freshwater locations such as lakes and rivers, most beaches are in coastal areas where wave or current action deposits and reworks sediments. Erosion and changing of beach geologies happens through natural processes, like wave action and extreme weather events. Where wind conditions are correct, beaches can be backed by coastal dunes which offer protection and regeneration for the beach. However, these natural forces have become more extreme due to climate change, permanently altering beaches at very rapid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Percussion Cap
The percussion cap or percussion primer, introduced in the early 1820s, is a type of single-use percussion ignition device for muzzle loader firearm locks enabling them to fire reliably in any weather condition. This crucial invention gave rise to the cap lock mechanism or percussion lock system using percussion caps struck by the hammer to set off the gunpowder charge in percussion guns including percussion rifles and cap and ball firearms. Any firearm using a caplock mechanism is a percussion gun. Any long gun with a cap-lock mechanism and rifled barrel is a percussion rifle. Cap and ball describes cap-lock firearms discharging a single bore-diameter spherical bullet with each shot. Description The percussion cap is a small cylinder of copper or brass with one closed end. Inside the closed end is a small amount of a shock-sensitive explosive material such as mercuric fulminate (discovered in 1800; it was the only practical detonator used from about 1850 to the early 20th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flintlock Mechanism
The flintlock mechanism is a type of lock (firearm), lock used on muskets, rifles, and pistols from the early 17th to the mid-19th century. It is commonly referred to as a "flintlock" (without the word ''mechanism''), though that term is also commonly used for the weapons themselves as a whole, and not just the lock mechanism. The flintlock mechanism, also known as the true flintlock, was developed in France in the early 17th century. It quickly replaced earlier technologies, such as the matchlock and wheellock and the earlier flintlocks. It continued to be in common use for over two centuries, until it was finally replaced by the percussion lock. History Flintlock firing mechanisms made their appearance in the 16th century in the form of the snaplock, the snaphance, the miquelet, and the doglock. The so-called ''true flintlock'' was developed in France in the early 17th century. Though its exact origins are not known, credit for the development of the true flintlock is usually gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flintlock
Flintlock is a general term for any firearm that uses a flint-striking lock (firearm), ignition mechanism, the first of which appeared in Western Europe in the early 16th century. The term may also apply to a particular form of the mechanism itself, also known as the ''flintlock mechanism, true flintlock'', that was introduced in the early 17th century, and gradually replaced earlier firearm-ignition technologies, such as the matchlock, the wheellock, and the earlier flintlock mechanisms such as snaplock and snaphaunce. The true flintlock continued to be in common use for over two centuries, replaced by percussion cap and, later, the Cartridge (firearms), cartridge-based systems in the early-to-mid 19th century. Although long superseded by modern firearms, flintlock weapons enjoy continuing popularity with Black powder, black-powder shooting enthusiasts. History French court gunsmith Marin le Bourgeoys made a firearm incorporating a flintlock mechanism for King Louis XIII of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Gunpowder
Gunpowder is the first explosive to have been developed. Popularly listed as one of the "Four Great Inventions" of China, it was invented during the late Tang dynasty (9th century) while the earliest recorded chemical formula for gunpowder dates to the Song dynasty (11th century). Knowledge of gunpowder spread rapidly throughout Asia and Europe, possibly as a result of the Mongol conquests during the 13th century, with written formulas for it appearing in the Middle East between 1240 and 1280 in a treatise by Hasan al-Rammah, and in Europe by 1267 in the ''Opus Majus'' by Roger Bacon. It was employed in warfare to some effect from at least the 10th century in weapons such as fire arrows, bombs, and the fire lance before the appearance of the gun in the 13th century. While the fire lance was eventually supplanted by the gun, other gunpowder weapons such as rockets and fire arrows continued to see use in China, Korea, India, and eventually Europe. Bombs too never ceased to deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
