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Armored Car

Armored car

Military armoured cars

reconnaissance vehicle.]] Military armoured cars are a type of armoured fighting vehicles and have wheels (from four to eight large off-road wheels) instead of tracks, and light armor. This gives them speed and range compared to most heavily armoured military vehicles, and as such their normal use in for reconnaissance, command/control, and communications (liaison between forward units). They may have a machine gun, an autocannon, a small gun, or may even be unarmed. autocannon during the Irish Civil War]] At the beginning of the 20th century a number of military armoured vehicles were manufactured by adding armour and weapons to existing vehicles: armoured tractors, armoured cars, and armoured trains are known. A prototype vehicle fully designed for a military purpose was the Tsar Tank, tested in Russia in August, 1915, however the design proved to be a fiasco. Subsequent armoured cars were less ambitious. Most of the early designs were a large car chassis to which an body made of steel plates had been added. Armoured cars have their use in peacekeeping or internal security duties where their appearance is less confrontational or threatening than tanks, their size and mobility are more in fitting with the urban environment and road damage is minimal. 1915 See also List of armoured cars.

Civilian armoured cars

Civilian armoured cars are modified versions of normal cars, made by replacing the windows with bulletresistant glass and inserting layers of armour under the outer skin of the car, a labor-intensive process that takes few weeks and costs about $100,000 in the U.S. There is typically no apparent external difference between a non-armoured and armoured version of the same car, in order to not look conspicuous. In most cases aramid composite and ballistic steel plates are used and the increased mass is offset by a souped-up engine and brakes, as composite armour is considerably more expensive. The cars also get a range of optional additional equipment: a fire extinguisher, rims in the wheels allowing to ride on empty tires for typically 15 or 50 km, explosion-resistant fuel tank, remote starting of the car, pressure and temperature control of the tires, a siren or alarm, and an intercom between the exterior and interior of the car. Sometimes they can also be sealed air-tight from inside, and carry an oxygen bottle, to protect against gas attacks (tear gas, etc). Armoured cars are in common use by people who feel at risk and can afford them - eg. politicians, enterpreneurs, ambassadors, in higher-risk areas, eg. Colombia, Iraq, Moscow, and Washington DC. Due to the amount of violence present in Mexico City, they are very popular there. Armoured cars can also help protect the passengers in a car accident. Civilian armoured cars can be divided into two types: # cars or trucks used in transporting valuables, such as large quantities of money which are armored and equipped to resist attempts at highway robbery or the hijacking of the cargo. They may be manned with armed guards but do not mount weapons. Armoured cars are usually operated by security firms, which provide secure transport for clients' property. # Armoured versions of cars or SUVs used as protection from crime or violence either by individuals who fear they may become victims, or in high risk environments. Diplomatic missions typically use armoured cars as standard vehicles, and many manufacturers or after market firms offer armoured versions of their vehicles. They are typically indistinguishable from the regular version on casual inspection from a distance.

External link

- [http://www.alpineco.com Armored Vehicles & Armored Cars, US]
- [http://www.armsvos.cz/Eng/index_eng.html Armored vehicles & Cars, European vendor]
- Category:Armored fighting vehicles by type ja:装甲車 zh-cn:装甲车

Wheel

: A wheel is a circular object that, together with an axle, allows low friction in motion by rolling. Common examples are found in transport applications. More generally the term is also used for circular objects rotating for other purposes, such as a wheel and axle and a flywheel.

Mechanics

Wheels are used in conjunction with an axle, either the wheel turns on the axle or the wheel is rigidly attached to the axle which then turns in bearings in the body of the vehicle. The mechanics are the same in either case. The low density of the friction (compared to dragging) is explained as follows:
- the sliding distance is reduced, because the sliding takes place between the wheels and the axles or between the axles and the bearings
- the coefficient of kinetic friction μ for the sliding friction is less Example:
- If dragging a 100 kg object for 10 m along a surface with μ = 0.5, the normal force on Earth is 980 N and the work done (required energy) is 980 × 10 × 0.5 = 4900 joules.
- Now give the object 4 wheels. The normal force between the 4 wheels and axles is the same (in total) 980 N, assume μ = 0.1, finally the most important factor is the wheel diameter (1000 mm) and axle diameter (50 mm). Now while the object still moves 10 m the sliding frictional surfaces only slide over each other a distance of 0.5 m. So work done is 980 x 0.5 x 0.1 = 49 joules. Additional energy is lost at the wheel to road interface (rolling friction), but it is deformation loss which can be very small. An example would be train wheels on rail tracks). The tradeoff is that a wheeled object in motion carries more momentum than dragging, and thus require an external force in the opposite direction in order to stop the object or change its direction, for example, such as brakes.

History of the wheel

brakesian "battle standard of Ur" (circa 2600 BC)]] According to most authorities, the wheel was invented in ancient Mesopotamia in the 5th millennium BC, originally in the function of potter's wheels. A possibly independent invention in China dates to around 2800 BC. It is also thought that the invention of the wheel dated back to Ancient India. Though they did not develop the wheel proper, the Olmec and certain other western hemisphere cultures seem to have approached the concept, as wheel-like worked stones have been found on objects identified as children's toys dating to about 1500 BC. The wheel was apparently unknown in sub-Saharan Africa, Australia, and the Americas until relatively recent contacts with Eurasians. Eurasian. The wheel is dated late second millennium BCE and was excavated at Choqa Zanbil.]] The invention of the wheel thus falls in the late Neolithic and may be seen in conjunction with the other technological advances that gave rise to the early Bronze Age. Note that this implies the passage of several wheel-less millennia, even after the invention of agriculture. Early wheels were simple wooden disks with a hole for the axle. In the early Roman empire, most horse-carts used a design featuring two chords across the wheel. The spoked wheel was invented much more recently, and allowed the construction of lighter and swifter vehicles. The earliest known examples are in the context of the Andronovo culture, dating to ca 2000 BC (see chariot). Celtic chariots introduced an iron rim around the wheel in the 1st millennium BC. The spoked wheel was in continued use without major modification until the early 20th century. The invention of the wheel turned out to be of great importance not only as a transportation device, but for the development of technology in general, important applications including the water wheel, the cogwheel (see also antikythera mechanism), the spinning wheel, the astrolabe or torquetum. More modern descendents of the wheel include the propeller, the jet engine, the flywheel (gyroscope) and the turbine. The central importance of the wheel also resulted in its becoming a strong cultural and spiritual metaphor for a cycle or regular repetition (see chakra, reincarnation). In July 2001, the wheel was the object of an innovative, but non-inventive, patent as a "circular transportation facilitation device". The patent was obtained by John Keogh, a lawyer from Melbourne, Australia, with the declared intention of demonstrating the unfairness and inaccuracy of the modern patent system.

References

# Casson, Lionel, "Travel in the Ancient World", The Johns Hopkins University Press, Baltimore, 1994. # http://news.bbc.co.uk/hi/english/world/asia-pacific/newsid_1418000/1418165.stm

Wheeled vehicles

Vehicles are classified according to number of wheels: # Unicycle, monocycle # Bicycle # Tricycle # Quadricycle

Other options

Ground transport devices without wheels include
- travois
- hovercraft
- magnetic levitation train
- sled

External links

- [http://spp.pinyin.info/abstracts/spp099_wheeled_vehicles.html early wheeled transport around the world, especially China] Category:Mechanical engineering ms:Roda ja:車輪 simple:Wheel

Vehicle armour

: For body armour see armour, for armoured forces see armoured. Military vehicles are commonly armoured to withstand the impact of shrapnel, bullets or shells, protecting the soldiers inside from enemy fire. The design and purpose of the vehicle determines the amount of armour plating carried, as the plating is often very heavy and excessive amounts of armour restrict mobility. The most heavily armoured vehicles today are the main battle tanks, which are the spearhead of the ground forces, and are designed to withstand anti-tank missiles, kinetic energy penetrators, NBC threats and in some tanks even steep-trajectory shells. The Israeli Merkava tanks were designed in a way that each tank component function as additional back-up armour to protect the crew. Outer armor is modular and enables quick replacement of damaged armour.
Technologies
For efficiency, the heaviest armour on an AFV is placed on its front: on the gun mantlet and glacis plate. Tank tactics require the vehicle to always face the likely direction of enemy fire as much as possible, even in defence or withdrawal operations. Sloping and curving armour both increase its protection. Given a fixed thickness of armour plate, a projectile striking at an angle must penetrate more armour than one impacting perpendicularly. An angled surface also increases the chance of deflecting a projectile. Appliqué armour screens have sometimes been bolted or welded onto armoured vehicles to increase protection. Beginning during the Cold War, many AFVs have spall liners inside of the armour, designed to protect crew and equipment inside from fragmentation (spallation) released from the impact of enemy shells, especially high explosive squash head warheads. Spall liners are made of kevlar or similar materials.
Spaced armour
kevlar Spaced armour can cause bullets and solid shot to tumble and deflect, reducing their penetrating ability—for which effect spaced armour was used as early as the First World War, on the Schneider CA1 and St Chamond tanks. Many early-WWII German tanks also had armoured skirts installed, to help protect their thinner side armour from antitank rifles and antitank guns. antitank rifle, May 1945.]] Spaced armour also takes advantage of the principle that a high explosive anti-tank (HEAT) warhead creates a focussed jet of plasticised metal, which dissipates with distance. The innovation of the Bazooka, Panzerfaust, and other HEAT weapons in the Second World War prompted the employment of factory-made and improvised stand-off armour. Relatively thin armour plates or even metal mesh were attached as side skirts or turret skirts on tanks and other armoured vehicles. Even today, light armoured vehicles mount panels of metal mesh and some main battle tanks carry rubber skirts to protect their relatively fragile suspension and front belly armour. In response to very heavy HEAT warheads, integral spaced armour was reintroduced in the 1960s on the German Leopard 1. There are hollow spaces inside this type of armour, increasing the length of travel from the exterior of the vehicle to the interior, in hopes of reducing the shaped charge's penetrating power; in some cases the interior surfaces of these hollow cavities are sloped, presenting angles to the anticipated path of the shaped charge's jet in order to further dissipate its power. Thus instead of having a single thirty-centimetre layer of steel armour, it is possible to have two fifteen-centimetre layers half a metre or more apart, giving far greater protection against shaped charges at no penalty in weight. The Whipple shield uses the principle of spaced armour to protect spacecraft from the impacts of micrometeoroids.
Composite armour
Composite armour (including Chobham armour) was developed in the 1960s by the British and first used on the American M1 Abrams but not, as is often presumed, on the German Leopard 2. It consists of layers of steel, ceramic, and plastic honeycomb, sometimes with layers of depleted uranium added. Composite is effective against both kinetic and shaped charge munitions. Against kinetic penetrators, the brittle ceramic blunts the projectile while the softer steel layers absorb its kinetic energy. Still, it is significantly less effective against KE-munitions, so sometimes depleted uranium layers are added to provide extra protection against these warheads. An alternate description of Chobham armour is that it combines spaced armour with composites. Supposedly the deeper interior heavy metal layer is a cast aluminium slab with rods of tungsten (encased in titanium) or depleted uranium running perpendicularly through it, intended to cause the points of high-velocity long-rod penetrator armour-piercing projectiles to deform, which sometimes causes the projectile to tip and strike the armour at an angle, presenting far greater surface area to the armour and therefore greatly increasing the resistance. Another type is perforated steel—armour with hollow perpendicular spaces serving the same function that they do in spaced armour, often filled with ceramic foam and backed by layers of Kevlar or similar material to trap and reduce fragmentation. This is the type used in the original version of the Leopard 2.
Reactive armour
Explosive reactive armour, initially developed by Israel, uses layers of high explosive sandwiched between steel plates. When a shaped-charge warhead hits, the explosive detonates and pushes the steel plates into the warhead, disrupting the charge's plasma flow. It is less effective against kinetic penetrators. Reactive armour poses a threat to friendly troops in the area of the vehicle. Non-explosive reactive armour is an advanced sort of spaced armour, using the changing geometry of materials under stress to increase its protection. Active protection systems use a sensor to detect an incoming projectile and explosively launch a counter-projectile into its path.
Electrically charged armour
Electrically charged armour is a recent development in the UK. A vehicle is fitted with two thin shells, separated by insulating material. The outer shell holds an enormous electrical charge, while the inner shell is a ground. If an incoming HEAT plasma-jet penetrates the outer shell and forms a bridge between the shells, the electrical energy discharges through the jet, disrupting it. Trials have so far been extremely promising, and it is hoped that improved systems could protect against KE penetrators. Developers of the Future Combat Systems series of armoured vehicles are considering this technology.
See also

- Armoured forces
- Body armour
- Active protection system
- Armoured fighting vehicle
- Main battle tank Category:Armor

Reconnaissance

during Operation Tempest, 1944]] Reconnaissance is the military term for the active gathering of information about an enemy, or other conditions, by physical observation. It is part of combat intelligence. Compare to counterintelligence. Often referred to as recce (British & Commonwealth) or recon (USA), the associated verb is reconnoiter in American English or reconnoitre in British English. Examples of reconnaissance include patrolling by troops, ships, submarines, or aircraft, or by setting up covert observation posts. Reconnaissance may also be carried out by satellites or unmanned aircraft. Espionage is not normally considered to be covered by the term reconnaissance, as reconnaissance involves uniformed military forces operating ahead of the main force, as oposed to non-combatant individuals within the enemy lines. Reconnaissance seeks to collect information about an enemy. This includes types of enemy units, locations, numbers, and intentions or activity. A number of acronyms exist for the information to be gathered - mainly coined by the US - including salt (size, activity, location, and time), salute (size, activity, location, unit, time, and equipment), sam & doc (strength, armament, movement, deployment, organization, and communications). Thus reconnaissance is a fundamental tactic which helps to build an intelligence picture.

Airborne photo reconnaissance

Espionage Main article: Surveillance aircraft On 16 October 1912 a Bulgarian Albatros aircraft was used to perform Europe's first reconnaissance flight in combat conditions. During the First World War, photo reconnaissance was one of the early uses of the aeroplane. Aviators such as Fred Zinn evolved an entire range of new flying and photography techniques to use the new technology in the equally new environment of trench warfare. Before the Second World War the conventional wisdom was to use converted bomber types for airborne photo reconnaissance. These bombers retained their defensive armament, which was vital since they were unable to avoid interception. In 1939 Flying Officer Maurice Longbottom of the RAF was among the first to suggest that airborne reconnaissance may be a task better suited to fast, small aircraft which would use their speed and high service ceiling to avoid detection and interception. Although this seems obvious now, with modern reconnaissance tasks performed by fast, high flying aircraft, at the time it was radical thinking. He proposed the use of Spitfires with their armament and radios removed and replaced with extra fuel and cameras. This led to the development of the Spitfire PR variants. Spitfires proved to be extremely successful in their reconnaissance role and there were many variants built specifically for that purpose. Immediately after World War II, long range aerial reconnaissance was taken up by adapted jet bombers - such as the English Electric Canberra, and its American development, the Martin B-57 - capable of flying higher or faster than the enemy. The onset of the Cold War led the development of highly specialized and secretive strategic reconnaissance aircraft (or "spyplanes"), such as the Lockheed U-2 and its successor, the SR-71 Blackbird (both from the United States). Flying these aircraft became an exceptionally demanding task, as much because of the aircraft's extreme speed and altitude as it was because of the risk of being captured as spies. As a result, the crews of these aircraft were invariably specially selected and trained. After the Korean war, RB-47 aircraft were used. These were at first converted B-47 jet bombers, but later were RB-47 aircraft, specially designed as reconnaissance planes. They did not carry any bombs. They had large cameras mounted in the belly of the plane, and with a truncated bomb bay used for carrying flash bombe.

Reconnaissance in force

Reconnaissance in force (RIF) is a type of military operation used specifically to probe an enemy's disposition. By mounting an offensive with considerable (but not decisive) force, the commander hopes to elicit a strong reaction by the enemy that reveals its own strength, deployment, and other tactical data. The RIF commander retains the option to fall back with the data or expand the conflict into a full engagement. Reconnaissance by fire (or speculative fire, "spec fire") is a tactic which applies a similar principle. When not trying to be stealthy, reconnaissance units may fire on likely enemy positions to provoke a reaction. The term reconnaissance in force is sometimes used ironically, as a means to disguise an intention of full engagement without specific instructions to do so, or as a way to provoke the enemy into a retaliatory action that puts them at a disadvantage.

External links

- [http://www.army.dnd.ca/ael/pubs/300-009/b-gl-394/002/fp-001/B-GL-394-002-FP-001.pdf Reconnaissance and Surveillance Operations]—Canadian Land Forces manual about armoured reconnaissance (PDF) Category:Military tactics ja:偵察

Autocannon

.]] An autocannon is a projectile weapon with a larger bore size than a machine gun, and a faster rate of fire than regular cannon used by artillery units. The term cannon was used during WWII to describe guns used in aircraft, where the distinction was that the shells were explosive. After the war similar guns were used with non-explosive rounds in the anti-tank role, and the name autocannon started to become popular. Autocannon today are typically distinguished by their incorporation of some method of automated loading and firing. Examples of an autocannon are the 25 mm M242 Bushmaster mounted on the M2 Bradley, the Bofors 40 mm anti-aircraft gun, or the 30 mm GAU-8 in the A-10 Warthog close air support airframe. Several tank guns have auto loading systems, and can be considered autocannon even though they are large-bore, up to 125 mm. Soviet and Russian armor, especially their main battle tanks, have used autoloaders extensively for many tank generations, even as US tanks keep human gun loaders. The French Leclerc also uses an automated 120mm gun. Typically, these are not commonly referred to as autocannon, but instead as tank guns. Category:Automatic cannons ja:機関砲

Irish Civil War

The Irish Civil War (June 1922–April 1923) was a conflict between supporters and opponents of the Anglo-Irish Treaty of December 6, 1921, which established the Irish Free State, precursor of today's Republic of Ireland. Opponents of the Treaty objected to the fact that it retained constitutional links between the United Kingdom and Ireland, and that the six counties of Northern Ireland would not be included in the Free State. The Civil War cost the lives of more than had died in the War of Independence that preceded it. It left Irish society deeply divided and its influence in Irish politics can still be seen to this day.

Background

War of Independence (second from left, front row), Arthur Griffith (fourth from left, front row) Eamon de Valera (centre, front row), W.T. Cosgrave (second from right, front row).]]

The Treaty

The Anglo-Irish Treaty arose from the Anglo-Irish War (or "Irish War of Independence"), fought between Irish separatists (organised as the extra-legal Irish Republic) and the British government, from 1919-1921. The treaty provided for a fully self-governing Irish state, controlling most of Ireland's population and area, and having its own army and police. However, rather than creating the independent republic favoured by many nationalists, it provided that the state would be a dominion of the British Empire with the British monarch as head of state. The treaty also stipulated that members of the new Irish Oireachtas (parliament) would have to take an "Oath of Allegiance" to the Free State constitution and an oath of fidelity to the British king. Under the treaty the state was not to be called a republic but a "free state" and it was only to include twenty-six southern and western counties of Ireland. Also, several strategic ports were to remain occupied by the Royal Navy. Nonetheless Michael Collins argued that the treaty gave "not the ultimate freedom that all nations aspire and develop, but the freedom to achieve it". Events were eventually to prove him right, as the Free State later evolved into an independent republic. However, Anti-Treaty militants in 1922 believed that the Treaty would never deliver full Irish independence.

Split in the Nationalist Movement

The split over the Treaty was deeply personal. The protagonists on both sides had been close friends and comrades during the War of Independence. This made their lethal disagreement over the Treaty all the more bitter. Michael Collins felt that Éamon de Valera had sent him to negotiate the Treaty because he knew that no more concessions could be got from the British and wanted Collins to take the blame for the compromise settlement. He therefore felt deeply betrayed when De Valera refused to stand by the agreement he had negotiated with David Lloyd George and Winston Churchill. Winston Churchill Dáil Éireann (the parliament of the Irish Republic) narrowly passed the Anglo-Irish Treaty in December 1921. Upon the Treaty's ratification Eamon de Valera resigned as President of the Republic and led the anti-treaty wing of Sinn Féin out of the Dáil. He challenged the right of the Dáil to approve the Treaty, saying that its members were breaking their oath to the Irish Republic and attempted unsuccessfully to set up his own rival government. Meanwhile under the leadership of Michael Collins and Arthur Griffith, the pro-treaty government set about establishing the Irish Free State, an organised national army to replace the IRA and a new police force. Supporters of the treaty came to be known as "pro-treaty", "National Army" or "Free State" forces. Its opponents were known as "anti-treaty", "Irregulars" or "Republicans" and continued to refer to themselves as the "IRA". The Anti-Treaty IRA claimed that it was defending the Irish Republic that had been declared in 1916 during the Easter Rising, that had been confirmed by the First Dáil and that had been invalidly set aside by those who accepted the compromise of the Free State. Éamon de Valera stated that he would serve as an ordinary IRA volunteer, and left the leadership of the Anti-Treaty Republicans to military leaders such as Liam Lynch.

Course of the war

Dublin Fighting

Liam Lynch In April 1922 anti-treaty militants led by Rory O'Connor occupied the Four Courts in Dublin, resulting in a tense stand-off. The Anti-Treaty Republicans wanted to spark a new armed confrontation with the British, which they hoped would unite the two factions of the IRA against their common enemy. However, for those who were determined to make the Free State into a viable, self-governing Irish state, this was an act of rebellion that would have to be put down by them rather than the British. Michael Collins attempted unsuccessfully to persuade the men holding the Four Courts to leave it before violence broke out. They refused and Collins decided to end the stand-off, under a British threat of re-occupation, by the bombarding the Four Courts garrison into surrender. This attack was not the opening shots of the war as skirmishes had taken place throughout the country when the British were handing over barracks. However this represented the 'point of no return' when all out war was ipso facto declared and the Civil War officially began. Michael Collins Michael Collins had accepted a British offer of artillery for use by the new Free State Army. The anti-treaty forces, who possessed only small arms, surrendered after several days of bombardment. In the chaos of the moment, the Irish Public Records Office was the centre of a huge explosion, blowing to pieces one thousand years of Irish state and religious archives. Several anti-Treaty leaders, notably Ernie O'Malley escaped from captivity to continue fighting elsewhere. Pitched battles continued in Dublin until July 5, as anti-Treaty IRA units occupied O'Connell Street - provoking a week's more street fighting. Among the casualties was Republican leader Cathal Brugha. Cathal Brugha When the fighting in Dublin died down, the Free State Government was left firmly in control of the Irish capital and the anti-treaty forces dispersed around the country, mainly to the south and west.Cathal Brugha At the start of the Civil War the IRA had split down the middle. The Anti-Treaty side had considerable support among IRA units, particularly in the south and west of Ireland. However the anti-treaty IRA lacked an effective command structure, a clear strategy and sufficient arms. They were forced to adopt a defensive stance throughout. Michael Collins and his commanders were able to build up an army which was able to overwhelm the Irregulars in the field. British supplies of artillery, aircraft, armoured cars, machine-guns, small arms and ammunition were much help to pro-treaty forces. By the end of the war, the Free State Army had swollen to over 55,000 men, far in excess of what the Irish state would need to maintain in peacetime. Collins' most ruthless officers were recruited from the Dublin Brigade of the IRA, (which he had commanded in the Irish War of Independence) and in particular from his assassination unit "The Squad". Towards the end of the war, they were implicated in some gruesome atrocities against Anti-Treaty guerrillas. Most of the Free State Army's officers were Pro-Treaty IRA. However, the bulk of the Free State Army was made up of unemployed Irish ex-servicemen, who had fought in the First World War in the British Army.

The Free State takes Major Towns

First World War With Dublin in pro-treaty hands, conflict spread throughout the country, with anti-Treaty forces briefly holding Cork, Limerick and Waterford as part of an independent "Munster Republic". However, the Anti-Treaty side were not equipped to wage conventional war, lacking artillery and armoured units, both of which the Free State obtained from the British. This meant that the large towns in Ireland were all easily taken by the Free State after only sporadic fighting. On August 10, Cork was retaken by sea, the last county to fall in the Munster Republic. Government victories in the major towns inaugurated a period of inconclusive guerrilla warfare marked by assassinations and executions of leaders formerly allied in the cause of Irish independence. Defence Minister Michael Collins was assassinated by anti-treaty republicans in August, near his home in Cork, in August 1922. Arthur Griffith, the Free State president had also died of a stroke ten days before, leaving the Free State government in the hands of William Cosgrave and the Free State Army under the command of General Richard Mulcahy. Richard Mulcahy

Atrocities, Executions and the End of the War

The final phase of the Civil War (1923) degenerated into a series of atrocities that left a lasting legacy of bitterness in Irish politics. The Anti-Treaty IRA began assassinating T.D.s who sat in the Dail, beginning with Sean Hales. In response, the Free State announced that it would be shooting IRA prisoners in reprisal for future "outrages". Accordingly, four prominent Republicans (one from each province), who had been held since the first week of the war - Rory O'Connor, Liam Mellows and two others - were executed in revenge for the killing of Hales. In all, the Free State sanctioned 77 official executions of Anti-Treaty prisoners during the civil war, including acclaimed author and treaty negotiator Robert Erskine Childers, - a number that was recalled by Fianna Fail members with bitterness for decades afterwards. In addition, Free State troops, particularly in County Kerry, where the guerrilla campaign was most bitter, began unofficial killings of captured Anti-Treaty militants. The most notorious example of this occurred at Ballyseedy, where 9 Republican prisoners were tied to a landmine, which was exploded and remaining survivors were then machine-gunned, with one of the prisoners Stephen Fuller, escaping to tell of the event afterwards. landmine The Anti-Treaty IRA were unable to maintain an effective guerrilla campaign, since the great majority of the Irish population did not support them. This was demonstrated in the elections immediately after the civil war, which Cumann na nGaedheal, the Free State party, won easily (See Irish general election, 1923 for the results). The Roman Catholic Church also supported the Free State, deeming it the lawful government of the country, denouncing the Anti-Treaty IRA and refusing to administer the Sacraments to Anti-Treaty militants. This stance would have influenced many Catholic Irish people at the time. The lack of public support for the Anti-Treaty IRA, the determination of the government to defeat them and their lack of will also contributed to the their defeat. As the conflict petered out into a de facto victory for the pro-Treaty side, de Valera asked for a ceasefire, followed in May 1923 by an order by the leadership of the Irregulars to dump arms rather than surrender them or continue a fight which they were incapable of winning. Some historians suggest that the death of Liam Lynch, an intransigent Republican leader, in a skirmish in the Knockmealdown mountains in County Waterford, allowed the more pragmatic Frank Aiken to call a halt to what seemed a futile struggle. Thousands of Anti -Treaty IRA members (including De Valera) were arrested by the Free State forces in the weeks after the end of the war, when they had dumped their arms and returned home.

Attacks on Loyalists

Although the cause of the civil war was the treaty, as the war developed the irregulars sought to identify their actions with the traditional republican cause of the "men of no property" and the result was that the war also saw large Loyalist landowners, and some not very well-off Loyalists, attacked and a large number of country estates occupied by small holders. Many, but not all of these, had supported the Crown forces during the War of Independence. This support was often largely moral, but sometimes it took the form of actively assisting the British in the conflict. This made their situation post-independence difficult, and in the anarchy of the Civil War they became easy targets. Sometimes these attacks had sectarian overtones, although most anti-treaty IRA men made no distinction between Catholic and Protestant supporters of the Irish government. The Free State made efforts to protect Protestants and their property, most notably in County Louth, where a special police force was set up specifically for this purpose. Controversy continues to this day about the extent of intimidation of Protestants at this time.

Cost and Results

The Civil War, though short, was bloody. It cost the lives of many senior figures, including Michael Collins. Both sides carried out brutal acts: the anti-treaty forces murdered TDs (MPs) and burned many historic homes (such as the famous Moore Hall in Mayo, because its owner had become a senator); the government executed anti-treaty prisoners, officially and unofficially. The pro-treaty National Army suffered 800 fatalities and perhaps as many as 4000 people were killed. As their forces retreated the Irregulars caused much destruction and the economy of the Free State suffered a hard blow in the earliest days of its existence as a result. In addition, about 12,000 Republicans were interned by the end of the Civil War, most of whom were not released until 1924. However, it has also been argued that the Irish Civil War could have been far worse than it actually was. The numbers killed were relatively modest by the standards of other contemporary civil wars - for example in Russia and Spain. Moreover, the fact the new Police force, the Gardai, were not involved, meant that it was possible for the Free State to establish an unarmed and politically neutral police service after the war. The fact that The Irish Civil War was fought between Irish Nationalist factions meant that the issue of Northern Ireland was ignored and Ireland was spared what could have been a far bloodier civil war based on ethnic and sectarian lines over the future of Ireland's six north-eastern counties. In fact, because of the Irish Civil War, Northern Ireland was able to consolidate its existence and partition of Ireland was confirmed for the foreseeable future. It was only after their defeat in the Civil War that Irish Republicans seriously considered whether to take armed action against British rule in Northern Ireland. In 1926, having failed to persuade the majority of the anti-treaty side of accepting the new status quo as a basis for an evolving Republic, a large faction led by de Valera and Aitken left to resume constitutional politics and to found the Fianna Fáil party. Fianna Fáil As with most civil wars, the internecine conflict left a bitter legacy, which continues to influence Irish politics to this day. The two largest political parties in the Republic are still Fianna Fáil and Fine Gael, the descendants respectively of the anti-treaty and pro-treaty forces of 1922. Until the 1970s, almost all of Ireland's prominent politicians were veterans of the civil war, a fact which poisoned the relationship between Ireland's two biggest parties. Examples of Civil War veterans include: Eamon de Valera, Frank Aiken, Todd Andrews, Sean Lemass, (Republican) and W.T. Cosgrave, Richard Mulcahy and Kevin O'Higgins (Free State). Moreover, many of these men's sons and daughters also became politicians, meaning that the personal wounds of the civil war were felt over three generations. In the 1930s after Fianna Fail took power for the first time, it looked possible for a while that the Civil War might break out again between the IRA and the pro-Free State Blueshirts. Fortunately, this crisis was averted and by the 1950s, political violence was no longer prominent in Southern Irish politics. Blueshirts However, the breakaway IRA continued (and continues in various forms) to exist. Up until the 1980s it still claimed to be the Provisional Government of the Irish Republic declared in 1918 and annulled by the Treaty of 1921. Some people, notably Michael McDowell, claim that this attitude, which dates from the Civil War, still underpins the politics of the Provisional IRA.

Footnotes

In the 1996 film Michael Collins, Eamon de Valera orders Collins' death. However, although de Valera was in the area at the time, he is not known to have been involved in the assassination.
Whose brother Noel was abducted and shot by Free State forces. His body was dumped in the Wicklow Mountains, near Glencree, where it is marked by a memorial.
O'Higgins was assasinated in 1927 by anti-treaty IRA members on his way to mass. He was killed in reprisal for what they viewed as his responsibility for executions of republicans during the civil war.

Sources

- Ernie O'Malley, The Singing Flame, Dublin 1978.
- M.E. Collins, Ireland 1868-1966, Dulin 1993.

Tractor

A tractor (from Latin trahere "to pull") is a device intended for drawing, towing or pulling something which cannot propel itself and, often, powering it too. Most commonly the word is used to describe a vehicle intended for such a task on some other vehicle or object. In Britain the word "tractor" usually means "farm tractor", and using "tractor" to mean other types of vehicles is known of in the vehicle trade but unfamiliar to much of the general public.

Farm tractor

Britain The most common use of the term tractor is for the vehicles used on farms. The farm tractor is used for pulling agricultural machinery or trailers, for ploughing, harrowing and similar tasks. The classic farm tractor is a simple open vehicle with two very large driving wheels on an axle below and slightly behind a single seat (the seat and steering wheel consequently are in the center) and the engine in front of the driver with two steerable wheels below the engine compartment. This basic design has remained unchanged for a number of years, but now enclosed cabs are available for many models of farm tractor. There are usually four foot-pedals, for the operator, on the floor of a tractor. The pedal on the left is the clutch. The operator presses on this pedal to disengage the transmission for either shifting gears or stopping the tractor. Two of the pedals on the right are the brakes. The left brake pedal stops the left rear wheel and the right brake pedal does the same with the right side. This independent left and right wheel braking augments the steering of the tractor when only the two rear wheels are driven. This is usually done when it is necessary to make a tight turn. The split brake pedal is also used in mud or soft dirt to control a tire that spins due to loss of traction. The operator presses both pedals together to stop the tractor. For tractors with additonal front-wheel drive this operation often engages the 4-wheel locking differential to help stop the tractor when travelling at road speeds. locking differential The pedal furthest to the right is the foot throttle. Unlike in automobiles, it can also be controlled from a hand-operated lever ("hand throttle"). This helps provide a constant speed in field work. It also helps provide continuous power for stationary tractors that are operating an implement by shaft or belt. The foot throttle gives the operator more automobile-like control over the speed of the tractor for road work. When travelling on the road in the UK it is mandatory to use the foot pedal to control engine speed. Most farm tractors use a manual transmission. They have several gear ratios that, generally, provide a range of speeds from less than one mile per hour up to about 25 miles per hour. Older tractors usually require that the operator depress the clutch in order to shift between gears (a limitation of straight-cut gears in the gearbox), but many modern tractors have eliminated this requirement with the intoduction of technologies such as continuously variable transmission. This allows the operator more and easier control over working speed than the throttle alone could provide. Slower speeds are necessary for most operations that are performed with a tractor. They help give the farmer a larger degree of control in certain situations, such as field work. However, when travelling on public roads, the slow operating speeds can cause problems, such as long queues or tailbacks, which can delay or aggrevate other road users. To alleviate conditions, some countries (for example the Netherlands) employ a road sign on some roads that means "no farm tractors". Some modern tractors, such as the JCB Fastrac, are now capable of much more tolerable road speeds of around 50 mph. JCB Modern farm tractors range in size from 18 to 500 horsepower (15 to 400 kW). Tractors can be generally classified as two-wheel drive, two-wheel drive with front wheel assist, or four-wheel drive (often with articulated steering). Variations of the classic style include the diminutive lawn tractors and their more capable and ruggedly constructed cousins, garden tractors, that range from about 10 to 25 horsepower and are used for smaller farm tasks and mowing grass and landscaping. Their size—especially with modern tractors—and the slower speeds are reasons motorists are urged to use caution when encountering a tractor on the roads. Modern tractors have roll-over protection systems (ROPS) to prevent an operator from being crushed if the tractor rolls over. This is especially important in open-air tractors where the ROPS is a steel beam that extends above the operator's seat. For tractors with operator cabs, the ROPS is part of the frame of the cab. Before ROPS were required many farmers died when their tractors rolled on top of them. Row-crop tractors, before ROPS, were particularly dangerous because of their 'tricycle' design with the two front wheels spaced close together and angled inward toward the ground. Many farmers were killed by rollovers while operating tractors along steep slopes. ROPS were first required by legislation in New Zealand in the 1960s. New Zealand Most tractors have a means to transfer the engine's power to another machine such as a baler, slasher or mower. Early tractors used belts wrapped around pulleys to power stationary equipment. Modern tractors use a power take-off shaft (PTO) to provide rotary power to machinery that may be stationary or pulled. Almost all modern tractors can also provide hydraulic and some electrical power. Farm implements can be attached to the rear of the tractor by either a drawbar or by a three-point hitch. The three-point hitch was invented by Harry Ferguson and has been a standard since the 1960s. Equipment attached to the three-point hitch can be raised or lowered hydraulically with a control lever. The equipment attached to the three-point hitch is usually completely supported by the tractor. Some farm-type tractors are found elsewhere than on farms: with large universities' gardening departments, in public parks or for highway workman use with blowtorch cylinders strapped to its sides and a pneumatic drill air compressor permanently fastened over its power take-off.

Steam tractors

The first mechanized farm implements in the 1800's and early 1900's were steam tractors which were not very safe and could explode or entangle their operators on belt driven attachments.

Engineering tractors

The durability and engine power of tractors made them very suitable for engineering tasks. Tractors can be fitted with engineering tools such as dozer blade, bucket, hoe, ripper, and so on. The most common attachments for the front of a tractor are dozer blade or a bucket. When attached with engineering tools the tractor is called an engineering vehicle. A bulldozer is a tracked-type tractor attached with blade in the front and a rope-winch behind. Bulldozers are very powerful tractors and have excellent ground-hold, as their main tasks are to push or drag things. Bulldozers have been further modified over time to evolve into new machines which are capable of working in ways that the original bulldozer can not. One example is that loader tractors were created by removing the blade and substituting a large volume bucket and hydraulic arms which can raise and lower the bucket, thus making it useful for scooping up earth, rock and similar loose material to load it into trucks. A front-loader or loader is a tractor with an engineering tool which consists of two hydraulic powered arms on either side of the front engine compartment and a tilting implement. This is usually a wide open box called a bucket but other common attachments are a pallet fork and a bale grappler. Other modifications to the original bulldozer include making the machine smaller to let it operate in small work areas where movement is limited. There are also tiny wheeled loaders, officially called Skid-steer loaders but nicknamed "Bobcat" after the original manufacturer, which are particularly suited for small excavation projects in confined areas.

Backhoe loader

Bobcat The most common variation of the classic farm tractor is the loader-backhoe, also called a backhoe-loader. As the name implies, it has a loader assembly on the front and a backhoe on the back. When both the loader and the backhoe are permanently attached it is almost never called a tractor, not generally used for towing and usually does not have a power take-off. When the backhoe is permanently attached, the machine usually has a seat that can swivel to the rear to face the hoe controls. Removable backhoe attachments almost always have a separate seat on the attachment. Backhoe-loaders are very common and can be used for a wide variety of tasks: construction, small demolitions, light transportation of building materials, powering building equipment, digging holes, breaking asphalt and paving roads. Some buckets have a retractable bottom, enabling them to empty their load more quickly and efficiently. Buckets with retractable bottoms are also often used for grading and scratching off sand. The front assembly may be a removable attachment or permanently mounted. Often the bucket can be replaced with other devices or tools. Their relatively small frame and precise control make backhoe-loaders very useful and common in urban engineering projects such as construction and repairs in areas too small for larger equipment. Their versatility and compact size makes them one of the most popular urban construction vehicles.

Other types of tractors

The term "tractor" or "tractor unit" (UK) is also applied to: ; road tractor : heavy-duty vehicles with large engines and several axles. These tractors are designed to pull long road trailers, most often for the transport of freight of some kind over a significant distance (See Semi-trailer). In England this type of "tractor" is often called an "artic cab". cab ; locomotive tractor (engines) : the amalgamation of machines, generators, controls and devices that comprise the traction component of railway vehicles vehicle ; artillery tractors. : highly-specialised vehicles used to tow guns of varying weights.

Tractors, agriculture and aerospace

In aircraft, a tractor configuration refers to the propellers being in front of the fuselage or wing. Conversely, if to the rear, it is a called a pusher configuration. NASA and other space Agencies use very large tractors to ferry launch vehicles like booster rockets and space shuttles from their hangars to (and in rare cases, from) the launchpad . Space technology has also trickled back down to agriculture in the form of GPS devices, and robust on-board computers installed as optional features on farm tractors. The spin-offs from the space race have actually facilitated automation in plowing and the use of driverless drone tractors that work in tandem with manned tractors on large corporate-scale farms.

In computers

A tractor is also the part of a computer printer that pulls paper into the device or pushes it along. This usually takes the form of a toothed gear that meshes with holes punched near the edge of the paper, or a belt or wheel with rubber or other high-friction surface that makes contact with the paper. ----

Manufacturers

Deere & Company White Tractors Allis Chalmers Case Corporation Miniapolis Molin Ford Tractor Co. New Holland International Harvester Steiger Tractor Company Big Bud ----

External links

- [http://www.livinghistoryfarm.org/farminginthe30s/machines_04.html Tractors in the 1930's]
- [http://www.antiquetractors.com/index.htm Antique Tractors]
- [http://home.howstuffworks.com/backhoe-loader.htm Howstuffworks.com: How a backhoe loader works]
- [http://www.pukeariki.com/en/stories/inventions/loubutler.asp Thinking around the problems]
- [http://www.webfarmer.com/ WebFarmer.com]
- [http://www.kpxtractors.com/ Tractor Implements and Backhoes] Category:Agricultural machinery Category:Engineering vehicles Category:Tractors ja:トラクター

Tsar Tank

The Tsar Tank (also known as the Netopyr (Нетопырь, Pipistrellus bat) or Lebedenko Tank) was an unusual Russian armored vehicle developed in 1914–1915. The project was scrapped after initial tests deemed the vehicle to be underpowered and vulnerable to artillery fire. The tank was different from modern tanks in that it didn't use caterpillar tracks—rather, it used a tricycle design. The two front spoked wheels were nearly 9 metres (27 feet) in diameter; the back one was a smaller, only 1.5 metres (5 feet) high, triple wheel, to ensure manoeuvrability. The upper cannon turret reached nearly 8 metres high. The hull was 12 metres wide with two more cannons in the sponsons. Additional weapons were also planned under the belly. The vehicle received its nickname because its model, when carried grabbed by the back wheel, resembled a bat hanging asleep. The huge wheels were intended to cross significant obstacles. However, due to miscalculations of the weight the back wheel was prone to be stuck in soft ground and ditches and the front wheels were sometimes insufficient to pull it out. This led to a fiasco of tests before the high commission in August 1915.

External links

- http://www.landships.freeservers.com/lebedenko_info.htm
- http://www.geocities.com/MadisonAvenue/Boardroom/7104/tsar/tsar_tank_main.htm
- http://www.render.ru/gallery/index.php3?act=award&id=7127 (3D photorealistic model) Category:Russian and Soviet tanks Category:World War I tanks

1915

1915 (MCMXV) was a common year starting on Friday (see link for calendar).

Events

- January 12 - The Rocky Mountain National Park is established by an act of the U.S. Congress.
- January 12 - United States House of Representatives rejects proposal to give women the right to vote.
- January 13 – An earthquake (6.8 in Richter scale) in Avezzano, Italy - 32.610 dead
- January 19 - George Claude patents the neon discharge tube for use in advertising.
- January 19 - German zeppelins bomb the cities of Great Yarmouth and King's Lynn in the United Kingdom for the first time, killing more than 20.
- January 21 - Kiwanis International is founded in Detroit, Michigan.
- January 27 - United States Marines occupy Haiti.
- January 27 - Chinese president Yuan Shikai declares himself Emperor
- January 28 - An act of the U.S. Congress creates the United States Coast Guard.
- January 31 - World War I: Germany uses poison gas against Russians.
- February 8 - The controversial film The Birth of a Nation by D.W. Griffith premieres (Los Angeles, California).
- February 12 - In Washington, DC the first stone of the Lincoln Memorial is put into place.
- March 3 - NACA, the predecessor of NASA, is founded.
- March 14 - World War I: Off the coast of Chile, the Royal Navy sinks the German battleship SMS Dresden.
- March 14 - Britain, France and Russia agree to give Constantinople and the Bosporus to Russia in case of victory (the treaty is later nullified by the Bolshevik revolution)
- March 18 - World War I: British attack on the Dardanelles fails.
- March 19 - Pluto is photographed for the first time but was not recognized as a planet.
- March 25 - US submarine F-4 sinks off Hawaii - 21 dead
- March 28 - The first Roman Catholic Liturgy is celebrated by Archbishop John Ireland at the newly consecrated Cathedral of Saint Paul in Saint Paul.
- April 13 - Mexican Revolution - Pancho Villa's attack against Alvaro Obregon's troops in Celaya. Charge of Villa's troops is no match against Obregon's barbed wire and machineguns
- April 22 - World War I: Second Battle of Ypres - German troops introduce poison gas at Ypres, Belgium.
- April 24 - Turkish troops attack the Armenian region of Van, starting the Armenian Genocide. In Constantinople, Turkish officers round up 300 ethnically Armenian intellectuals and execute them
- April 25 - The Anzac tradition begins during World War I with a landing at Gallipoli on the Turkish coast.
- April 30 - Australian submarine AE2 sunk in Sea of Marmora.
- May 3 - John McCrae writes In Flanders Fields
- May 7 - World War I: The RMS Lusitania is sunk by a German U-boat killing 1,198.
- May 9 - World War I: Second Battle of Artois - German and French forces fight.
- May 17 - The last purely Liberal government in the United Kingdom ends when Prime Minister Herbert Henry Asquith forms an all party coalition.
- May 22 - Quintinshill railway disaster, Scotland, UK. 200 killed.
- May 23 - World War I: Italy joins the Allies after they declare war on Austria-Hungary.
- June 3 - Troops of Obregon and Villa clash at León. Obregon loses his right arm in grenade attack but Villa is decisively defeated
- June 9 - U.S. Secretary of State William Jennings Bryan resigns over a disagreement regarding his nation's handling of the RMS Lusitania sinking.
- June 16 - Foundation of the British Women's Institute
- June 29 – Roger Casement is sentenced to be hanged for treason
- July 24 - The steamer Eastland capsizes in central Chicago, Illinois, with the loss of 845 lives.
- August 5 – 23 - hurricane over Galveston and New Orleans – 275 dead
- August 6 - World War I: Battle of Sari Bair begins - The Allies mount a diversionary attack timed to coincide with a major Allied landing of reinforcements at Suvla Bay.
- August 16 - The Entente promises the Kingdom of Serbia, should victory be achieved over Austro-Hungary and it's allied Central Powers, the territories of Baranja, Srem and Slavonia from the Cisleithanian part of the Dual Monarchy; Bosnia and Herzegovina; and eastern 2/3 of Dalmatia (from the river of Krka to Bar).
- August 17 - Jewish American Leo Frank is lynched for the alleged murder of a 13-year-old girl in Atlanta, Georgia.
- September 6 - The first prototype tank is tested for the British Army for the first time.
- September 7 - Former cartoonist John B. Gruelle is given a patent for his Raggedy Ann doll.
- October 12 - World War I: British nurse Edith Cavell is executed by a German firing squad for helping Allied soldiers escape from Belgium.
- October 19 - US recognizes Mexican government of Victoriano Carranza de facto (not de jure until 1917)
- October 27 - William Morris Hughes becomes 7th Prime Minister of Australia.
- November 25 - The theory of general relativity is formulated.
- December 26 - Irish Republican Brotherhood Military Council decides to stage a rising on Easter Sunday 1916.

Unknown dates

- Alfred Wegener proposes the theory of Pangea.
- Emory College is rechartered as Emory University, and plans to move its main campus from Oxford, Georgia to Atlanta.
- U.S. recognizes government of President Venustiano Carranza of Mexico.
- Lord Beaverbrook buys the London Daily Express.
- Automobile speed record of 102.6 m.p.h. set at Sheepshead Bay, N.Y.. by Gil Anderson driving a Stutz.
- The first stop sign appears in Detroit, Michigan.
- Female suffrage in Denmark and Iceland
- Henri Désiré Landru begins his serial kills
- Typhoid Mary isolated

Ongoing events

- World War I (1914-1918)
- Armenian Genocide (1915-1918)
- Assyrian Genocide (1914-1922)

Births

January

- January 5 - Arthur H. Robinson, American geographer and cartographer (d. 2004)
- January 14 - Mark Goodson, American television game show producer (d. 1992)
- January 20 - Ghulam Ishaq Khan, President of Pakistan
- January 23 - Arthur Lewis, British economist, Nobel Prize laureate (d. 1991)
- January 24 - Robert Motherwell, American painter (d. 1991)
- January 30 - Joachim Peiper, German SS officer (d. 1976)
- January 31 - Alan Lomax, American folklorist and musicologist (d. 2002)
- January 31 - Thomas Merton, American monk and author (d. 1968)

February

- February 1 - Artur London, Czech statesman (d. 1986)
- February 1 - Sir Stanley Matthews, English footballer (d. 2000)
- February 2 - Khushwant Singh, Indian writer
- February 4 - Sir Norman Wisdom, English comedian, singer, and actor
- February 5 - Robert Hofstadter, American physicist, Nobel Prize laureate (d. 1990)
- February 16 - Jim O'Hora, American college football coach, (d. 2005)
- February 28 - Peter Medawar, Brazilian-born scientist, recipient of the Nobel Prize in Physiology or Medicine (d. 1987)

March

- March 9 - John Edgar "Johnnie" Johnson, English WW2 pilot (d. 2001)
- March 10 - Harry Bertoia, Italian artist and designer (d. 1978)
- March 11 - Vijay Hazare, Indian cricketer (d. 2004)
- March 14 - Alexander Brott, Canadian conductor and composer (d. 2005)
- March 20 - Sviatoslav Richter, Ukrainian born Soviet pianist (d. 1997)
- March 23 - Vasily Zaitsev, Soviet sniper, World War II hero (d. 1991).
- March 30 - Arsenio Erico, Paraguayan footballer in Argentina (d. 1977)
- March 31 - Albert Hourani, English Middle Eastern historian (d. 1993)

April

- April 4 - Muddy Waters, American blues musician (d. 1983)
- April 7 - Billie Holiday, American jazz and blues singer (d. 1959)
- April 21 - Anthony Quinn, Mexican actor (d. 2001)

May

- May 1 - Krystyna Skarbek, Polish-born heroine of World War II (d. 1952)
- May 1 - Archie Williams, American athlete (d. 1993)
- May 2 - Doris Fisher, American singer and songwriter (d. 2003)
- May 5 - Alice Faye, American entertainer (d. 1998)
- May 6 - Orson Welles, American film director (d. 1985)
- May 10 - Denis Thatcher, husband of Margaret Thatcher (d. 2003)
- May 15 - Paul Samuelson, American economist, Nobel Prize laureate
- May 20 - Moshe Dayan, Israeli military leader and politician (d. 1981)
- May 26 - Sam Edwards, American actor (d. 2004)
- May 29 - Karl Münchinger, German conductor (d. 1990)

June

- June 1 - John Randolph, American actor (d. 2004)
- June 10 - Saul Bellow, Canadian-born writer, Nobel Prize laureate (d. 2005)
- June 15 - Thomas Huckle Weller, American virologist, recipient of the Nobel Prize in Physiology or Medicine
- June 17 - Karl Targownik, Hungarian psychiatrist and Holocaust survivor (d. 1996)
- June 24 - Sir Fred Hoyle, British astronomer (d. 2001)

July-August

- July 28 - Charles Townes, American physicist, Nobel Prize laureate
- August 22 - Hugh Paddick, British actor (d. 2000)
- August 27 - Norman F. Ramsey, American physicist, Nobel Prize laureate

September-October

- September 23 - Clifford Shull, American physicist, Nobel Prize laureate (d. 2001)
- September 30 - Lester Maddox, Governor of Georgia (d. 2003)
- October 13 - Terry Frost, English artist (d. 2003)
- October 9 - Clifford M. Hardin, U.S. Secretary of Agriculture
- October 17 - Arthur Miller, American playwright (d. 2005)
- October 24 - Bob Kane, American comic book creator, Creator of Batman (d. 1998)
- October 24 - Tito Gobbi, Italian baritone (d. 1984)
- October 29 - William Berenberg, American physician (d. 2005)

November

- November 9 - Sargent Shriver, American politician
- November 11 - William Proxmire, American politician
- November 12 - Roland Barthes, French philosopher and literary critic (d. 1980)
- November 14 - Martha Tilton, Britih actress
- November 19 - Earl Wilbur Sutherland Jr., American physiologist, Nobel Prize laureate (d. 1974)
- November 25 - Augusto Pinochet, President of Chile
- November 30 - Brownie McGhee, American musician (d. 1996)
- November 30 - Henry Taube, Canadian-born chemist, Nobel Prize laureate (d. 2005)

December

- December 7 - Eli Wallach, American actor
- December 8 - Ernest Lehman American screenwriter (d. 2005)
- December 9 - Elisabeth Schwarzkopf, German soprano
- December 12 - Frank Sinatra, American entertainer (d. 1998)
- December 19 - Edith Piaf, French singer (d. 1963)
- December 27 - Gyula Zsengellér, Hungarian footballer

Deaths

- January 15 - Mary Slessor, Scottish Christian missionary (b. 1848)
- February 5 - Ross Barnes, baseball player (b. 1850)
- March 31 - Wyndham Halswelle, Scottish runner (b. 1882)
- April 16 - Nelson W. Aldrich, Senator from Rhode Island (b. 1841)
- April 23 - Rupert Brooke, English poet (b. 1887)
- July 16 - Ellen G. White, American prophetess, co-founder of Seventh-Day Adventism (b. 1827)
- August 20 - Paul Ehrlich, German scientist, recipient of the Nobel Prize in Physiology or Medicine (b. 1854)
- August 26 - John Bunny American silent film comedian (b. 1863)
- September 9 - Albert Spalding, baseball player and sporting goods manufacturer (b. 1850)
- September 13 - Andrew L. Harris, American Civil War hero and Governor of Ohio (b. 1835)
- October 12 - Charles Sorley, British poet (b. 1895)
- November 15 - Booker T. Washington, African-American educator (b. 1856)

Marriages

- January 20 - Richard E. Byrd & Marie Donaldson
- April 27 - Bert Wheeler & Margaret Grae
- June 26 - T.S. Eliot & Vivienne Haigh-Wood
- August 11 - Buck Jones & Odelle Osborne
- August 29 - Julian Reed & Mrs. Mary Darcey Goodwin
- September 21 - Averell Harriman & Kitty Lawrence
- September 22 - Siegfried Wagner & Winifred Wagner
- October 21 - Graciliano Ramos & Maria Augusta de Barros
- December 5 - Kurt Schwitters & Helma Fischer
- December 12 - Mae Busch & Francis McDonald
- December 17 - Benito Mussolini & Donna Rachele Guidi
- December 18 - Paul Hoffman & Dorothy Brown
- December 18 - Woodrow Wilson & Edith Bolling Galt

Nobel Prizes

- Chemistry - Richard Willstätter
- Literature - Romain Rolland
- Medicine - not awarded
- Peace - not awarded
- Physics - William Henry Bragg and William Lawrence Bragg Category:1915 ---- ko:1915년 ms:1915 ja:1915年 simple:1915 th:พ.ศ. 2458

Bulletresistant glass

Bulletproof glass is usually transparent material, such as polycarbonate thermoplastic (i.e. Lexan but also called Tuffak and Cyrolon),or layers of laminated glass, that provides the appearance and light-transmitting behavior of standard glass but offers varying degrees of protection from small arms fire. Bulletproof glass usually consists of a polycarbonate layer sandwiched between layers of regular glass. A bullet pierces the exterior glass layer with ease, but the strong polycarbonate layer stops the bullet's motion before it can pierce the inner layer of glass. Bulletproof glass is usually 70-75mm thick. Historically, bulletproof glass was built from glass sheets glued together using liquid rubber. These bulletproof glass blocks, already in common use during WWII, were often 100-120mm thick and extremely heavy.

One-way bulletproof glass

Advances in bulletproof glass have led to the invention of one-way bulletproof glass, such as used in some bank armored cars. This glass will resist incoming small arms fire striking the outside of the glass, but will allow those on the other side of the glass, such as guards firing from inside the armored car, to fire through the glass at the exterior threat. One-way bulletproof glass is usually made up of two layers, a brittle layer on the outside and a flexible one on the inside. When a bullet is fired from the outside it hits the brittle layer first, shattering an area of it. This shattering absorbs some of the bullet's kinetic energy, and spreads it on a larger area. When the slowed bullet hits the flexible layer, it is stopped. However, when a bullet is fired from the inside, it hits the flexible layer first. The bullet penetrates the flexible layer because its energy is focused on a smaller area, the brittle layer then shatters outward due to the flexing of the inner layer and does not hinder the bullet's progress.

Recent advances in bullet resistant glass composition

U.S. military researchers are moving quickly to develop a new class of transparent armour incorporating aluminum oxynitride (Trade name: ALON) as the outside "strike plate" layer ([http://www.af.mil/news/story.asp?id=123012131 Air Force Research Lab article]). It is much lighter and performs much better than traditional glass/polymer laminates. This allows aluminum oxynitride "glass" to defeat threats surpassing 50 caliber armor piercing rounds using material that is not prohibitively heavy.

Composite material

Composite materials (or composites for short) are engineered materials made from two or more constituent materials that remain separate and distinct on a macroscopic level while forming a single component. There are two categories of constituent materials: matrix and reinforcement. At least one portion (fraction) of each type is required. The matrix material surrounds and supports the reinforcement materials by maintaining their relative positions. The reinforcements impart their special mechanical, electrical and physical properties to enhance the matrix properties. A synergism produces material properties unavailable from naturally occurring materials. Due to the wide variety of matrix and reinforcement materials available, the design potentials are incredible. The most primitive composite materials comprised straw and mud in the form of bricks for building construction. Th