A knife is a tool with a cutting edge or blade attached to a handle. Mankind's first tool, knives were used at least two-and-a-half million years ago, as evidenced by the Oldowan tools. Made of rock, bone and obsidian, over the centuries, in step with improvements in metallurgy or manufacture, knife blades have been made from bronze, iron, steel and titanium. Most modern knives have either folding blades. Knives can serve various purposes. Hunters use a hunting knife, soldiers use the combat knife, scouts and hikers carry a pocket knife. A modern knife consists of: the blade the handle the point – the end of the knife used for piercing the edge – the cutting surface of the knife extending from the point to the heel the grind – the cross section shape of the blade the spine – the thickest section of the blade. Single-edged knives may have a reverse edge or false edge occupying a section of the spine; these edges are serrated and are used to further enhance function. The handle, used to grip and manipulate the blade safely, may include a tang, a portion of the blade that extends into the handle.
Knives are made with full tangs. The handle may include a bolster, a piece of heavy material situated at the front or rear of the handle; the bolster, as its name suggests, is used to mechanically strengthen the knife. Knife blades can be manufactured from a variety of materials, each of which has advantages and disadvantages. Carbon steel, an alloy of iron and carbon, can be sharp, it holds its edge well, remains easy to sharpen, but is vulnerable to rust and stains. Stainless steel is an alloy of iron, chromium nickel, molybdenum, with only a small amount of carbon, it is not able to take quite as sharp an edge as carbon steel, but is resistant to corrosion. High carbon stainless steel is stainless steel with a higher amount of carbon, intended to incorporate the better attributes of carbon steel and stainless steel. High carbon stainless steel blades do not discolor or stain, maintain a sharp edge. Laminated blades use combining the attributes of both. For example, a harder, more brittle steel may be sandwiched between an outer layer of softer, stainless steel to reduce vulnerability to corrosion.
In this case, the part most affected by corrosion, the edge, is still vulnerable. Damascus steel is a form of pattern welding with similarities to laminate construction. Layers of different steel types are welded together, but the stock is manipulated to create patterns in the steel. Titanium is a metal that has a better strength-to-weight ratio, is more wear resistant, more flexible than steel. Although less hard and unable to take as sharp an edge, carbides in the titanium alloy allow them to be heat-treated to a sufficient hardness. Ceramic blades are hard and lightweight: they may maintain a sharp edge for years with no maintenance at all, but are as fragile as glass and will break if dropped on a hard surface, they are immune to common corrosion, can only be sharpened on silicon carbide sandpaper and some grinding wheels. Plastic blades are not sharp and serrated, they are disposable. Steel blades are shaped by forging or stock removal. Forged blades are made by heating a single piece of steel shaping the metal while hot using a hammer or press.
Stock removal blades are shaped by removing metal. With both methods, after shaping, the steel must be heat treated; this involves heating the steel above its critical point quenching the blade to harden it. After hardening, the blade is tempered to make the blade tougher. Mass manufactured kitchen cutlery uses both the stock removal processes. Forging tends to be reserved for manufacturers' more expensive product lines, can be distinguished from stock removal product lines by the presence of an integral bolster, though integral bolsters can be crafted through either shaping method. Knives are sharpened in various ways. Flat ground blades have a profile that tapers from the thick spine to the sharp edge in a straight or convex line. Seen in cross section, the blade would form a long, thin triangle, or where the taper does not extend to the back of the blade, a long thin rectangle with one peaked side. Hollow ground blades have beveled edges; the resulting blade has a thinner edge, so it may have better cutting ability for shallow cuts, but it is lighter and less durable than flat ground blades and will tend to bind in deep cuts.
Petition of Right
The Petition of Right is a major English constitutional document that sets out specific liberties of the subject that the king is prohibited from infringing. Passed on 7 June 1628, the Petition contains restrictions on non-Parliamentary taxation, forced billeting of soldiers, imprisonment without cause, the use of martial law. Following disputes between Parliament and King Charles I over the execution of the Thirty Years' War, Parliament refused to grant subsidies to support the war effort, leading to Charles gathering "forced loans" without Parliamentary approval and arbitrarily imprisoning those who refused to pay. Moreover, the war footing of the nation led to the forced billeting of soldiers within the homes of private citizens, the declaration of martial law over large swathes of the country. In response, the House of Commons prepared a set of four Resolutions, decrying these actions and restating the validity of Magna Carta and the legal requirement of habeas corpus; these were rejected by Charles, who announced that Parliament would be dissolved.
Accordingly, a committee under Sir Edward Coke drafted such a petition, it was passed by the Commons on 8 May and sent to the House of Lords. After three weeks of debates and conferences between the two chambers, the Petition of Right was ratified by both houses on the 26th and 27 May. Following additional debates in which the King restricted the right of the Commons to speak, he bowed to the pressure. Unhappy with the method chosen, both houses joined together and demanded the King ratify the Petition, which he did on 7 June. Despite debates over its legal status, the Petition of Right was influential. Domestically, the Petition is seen as "one of England's most famous constitutional documents", of equal value to the Magna Carta and Bill of Rights 1689. In a period in which Charles's main protection from the Commons was the House of Lords, the willingness of both chambers to work together marked a new stage in the constitutional crisis that would lead to the English Civil War; the Petition remains in force in the United Kingdom and, thanks to Imperial legislation, many parts of the Commonwealth of Nations including Australia and New Zealand.
Internationally, it helped influence the Massachusetts Body of Liberties, is seen as a predecessor to the Third, Fifth and Seventh amendments to the Constitution of the United States. On 27 March 1625, King James I of England died, was succeeded by his son, who became Charles I. Along with the throne, Charles inherited the Thirty Years' War, in which Christian IV of Denmark and Frederick V, Elector Palatine, married to Charles's sister Elizabeth, were attempting to take back their hereditary lands and titles from the Habsburg Monarchy. James had caused significant financial problems with his attempts to support Christian and Frederick, it was expected that Charles would be more amenable to prosecuting the war responsibly. After he summoned a new Parliament to meet in April 1625, it became clear; the House of Commons refused, instead passed two bills granting him only £112,000. In addition, rather than renewing the customs due from Tonnage and Poundage for the entire life of the monarch, traditional, the Commons only voted them in for one year.
Because of this, the House of Lords rejected the bill, leaving Charles without any money to provide for the war effort. Displeased with this, Charles adjourned it on 11 July, but finding himself in need of money recalled the Members on 1 August, when they met in Oxford. Not only did the Commons continue to refuse to provide money, led by Robert Phelips and Sir Edward Coke they began investigating the Duke of Buckingham. Buckingham, Charles's favourite, was in charge of prosecuting the war, with it going badly the Commons inquired into Buckingham's use of previous grants, various controversies within the admiralty; this was a pretext to impeachment, Charles reacted by dissolving Parliament less than two weeks on 12 August. By 1627, with England still at war, Charles decided to raise "forced loans". Anyone who refused to pay would be imprisoned without trial, if they resisted, sent before the Privy Council. Although the judiciary refused to endorse these loans, they succumbed to pressure after the Chief Justice of the King's Bench, Sir Randolph Crewe, was dismissed.
For refusing to contribute to the forced loan, over 70 gentlemen were arbitrarily jailed, without trial or charges brought against them. Five of them, Sir Thomas Darnell, Sir John Corbet, Sir Walter Erle, Sir John Heveningham and Sir Edmund Hampden, attempted to gain their freedom, petitioning the Court of King's Bench for a writ of habeas corpus; these were awarded on 3 November 1627, with the court ordering the bailiffs to present these prisoners to the King's Bench for examination by 8 November. None of the prisoners were presented, because the bailiffs were unable to determine what they were charged with; this led to the Five Knights' Case, known as Darnell's Case. Darnell, unnerved by the situation, ceased pursuing his freedom, the other four secured writs instead, represented by John Bramston, Henry Calthorp and John Selden; the judges denied the defendants bail, concluding that if no charges had been brought, "the could not be freed as the offence was too dangerous for public discussion".
Augustine Washington Sr. was the father of the first U. S. President George Washington, he was a planter and slaveholder. Augustine Washington was born in Westmoreland County, Virginia, on November 12, 1694 to Capt. Lawrence Washington, a militia captain and a member of the Virginia House of Burgesses, Mildred Warner, his paternal grandparents were his first wife, Anne Pope. Augustine was only four years old, he inherited about 1,000 acres on Bridges Creek in Westmoreland County. When Washington came of age in 1715, he married Jane Butler, an orphan who had inherited about 640 acres from her father; the young couple settled on the Bridges Creek property. Washington was active in local politics, he took the oath as justice of the peace for the county court in July 1716, served as county sheriff. In 1718, Washington purchased land on Popes Creek. About 1726, he had a new house built there. In the same year, he purchased the Little Hunting Creek property from his sister Mildred. Washington and his first wife, Jane Butler, had only two of whom lived to adulthood.
In 1725, Augustine entered into an agreement with the Principio Company of England to start an iron works on Accokeek Creek in Stafford County. After Jane's death in November 1728 or 1729, Washington married Mary Ball in 1731, in 1735, the family moved to the Little Hunting Creek property, closer to the Accokeek Furnace. In 1738, Augustine Washington purchased the 150-acre Strother property across the Rappahannock River and moved the family there at the end of that same year. After Washington's death in 1743 at the age of 48, his son George inherited the former Strother property and its slaves; as he was only 11 years old, his mother Mary managed the property for him. She lived on the property until 1772 when she was 64. George moved her to a house in Fredericksburg. Lawrence inherited the Little Hunting Creek property and renamed his property Mount Vernon, in honor of Admiral Edward Vernon, with whom he had served in the Royal Navy in 1741 during the Battle of Cartagena de Indias during the War of Jenkins' Ear. Augustine Jr. inherited the Popes Creek property and slaves.
At his death, Augustine Washington Sr. held a total of 64 slaves who were assigned among the various plantations. According to Augustine's will, if Lawrence died without children, the Little Hunting Creek property would be given to Augustine Jr. with the stipulation that he must give Popes Creek to George. If Augustine Jr. did not want the Little Hunting Creek property, it would be inherited by George. At Lawrence's death, Augustine Jr. did not want to give up Popes Creek, Lawrence's only surviving child Sarah lived only until 1754. Lawrence Washington's widow Ann had a life interest in the Little Hunting Creek plantation; as she remarried and was not living at Mount Vernon, she leased the property to George beginning in 1754. Upon her death in 1761, George Washington inherited the plantation outright. Butler Washington Lawrence Washington Augustine Washington Jr. Jane Washington George Washington Betty Washington Lewis Samuel Washington John Augustine Washington Charles Washington Mildred Washington Ancestry of George Washington List of George Washington articles Freeman, Douglas Southall.
George Washington: A Biography. New York: Charles Scribner's Sons. "George Washington's Heritage", March 26, 2005, Fredricksburg.com. "Lawrence Washington History, 1659-1698", National Park Service
The United Kingdom the United Kingdom of Great Britain and Northern Ireland, sometimes referred to as Britain, is a sovereign country located off the north-western coast of the European mainland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, many smaller islands. Northern Ireland is the only part of the United Kingdom that shares a land border with another sovereign state, the Republic of Ireland. Apart from this land border, the United Kingdom is surrounded by the Atlantic Ocean, with the North Sea to the east, the English Channel to the south and the Celtic Sea to the south-west, giving it the 12th-longest coastline in the world; the Irish Sea lies between Great Ireland. With an area of 242,500 square kilometres, the United Kingdom is the 78th-largest sovereign state in the world, it is the 22nd-most populous country, with an estimated 66.0 million inhabitants in 2017. The UK is constitutional monarchy; the current monarch is Queen Elizabeth II, who has reigned since 1952, making her the longest-serving current head of state.
The United Kingdom's capital and largest city is London, a global city and financial centre with an urban area population of 10.3 million. Other major urban areas in the UK include Greater Manchester, the West Midlands and West Yorkshire conurbations, Greater Glasgow and the Liverpool Built-up Area; the United Kingdom consists of four constituent countries: England, Scotland and Northern Ireland. Their capitals are London, Edinburgh and Belfast, respectively. Apart from England, the countries have their own devolved governments, each with varying powers, but such power is delegated by the Parliament of the United Kingdom, which may enact laws unilaterally altering or abolishing devolution; the nearby Isle of Man, Bailiwick of Guernsey and Bailiwick of Jersey are not part of the UK, being Crown dependencies with the British Government responsible for defence and international representation. The medieval conquest and subsequent annexation of Wales by the Kingdom of England, followed by the union between England and Scotland in 1707 to form the Kingdom of Great Britain, the union in 1801 of Great Britain with the Kingdom of Ireland created the United Kingdom of Great Britain and Ireland.
Five-sixths of Ireland seceded from the UK in 1922, leaving the present formulation of the United Kingdom of Great Britain and Northern Ireland. There are fourteen British Overseas Territories, the remnants of the British Empire which, at its height in the 1920s, encompassed a quarter of the world's land mass and was the largest empire in history. British influence can be observed in the language and political systems of many of its former colonies; the United Kingdom is a developed country and has the world's fifth-largest economy by nominal GDP and ninth-largest economy by purchasing power parity. It has a high-income economy and has a high Human Development Index rating, ranking 14th in the world, it was the world's first industrialised country and the world's foremost power during the 19th and early 20th centuries. The UK remains a great power, with considerable economic, military and political influence internationally, it is sixth in military expenditure in the world. It has been a permanent member of the United Nations Security Council since its first session in 1946.
It has been a leading member state of the European Union and its predecessor, the European Economic Community, since 1973. The United Kingdom is a member of the Commonwealth of Nations, the Council of Europe, the G7, the G20, NATO, the Organisation for Economic Co-operation and Development and the World Trade Organization; the 1707 Acts of Union declared that the kingdoms of England and Scotland were "United into One Kingdom by the Name of Great Britain". The term "United Kingdom" has been used as a description for the former kingdom of Great Britain, although its official name from 1707 to 1800 was "Great Britain"; the Acts of Union 1800 united the kingdom of Great Britain and the kingdom of Ireland in 1801, forming the United Kingdom of Great Britain and Ireland. Following the partition of Ireland and the independence of the Irish Free State in 1922, which left Northern Ireland as the only part of the island of Ireland within the United Kingdom, the name was changed to the "United Kingdom of Great Britain and Northern Ireland".
Although the United Kingdom is a sovereign country, Scotland and Northern Ireland are widely referred to as countries. The UK Prime Minister's website has used the phrase "countries within a country" to describe the United Kingdom; some statistical summaries, such as those for the twelve NUTS 1 regions of the United Kingdom refer to Scotland and Northern Ireland as "regions". Northern Ireland is referred to as a "province". With regard to Northern Ireland, the descriptive name used "can be controversial, with the choice revealing one's political preferences"; the term "Great Britain" conventionally refers to the island of Great Britain, or politically to England and Wales in combination. However, it is sometimes used as a loose synonym for the United Kingdom as a whole; the term "Britain" is used both as a synonym for Great Britain, as a synonym for the United Kingdom. Usage is mixed, with the BBC preferring to use Britain as shorthand only for Great Britain and the UK Government, while accepting that both terms refer to the United K
The Royal Navy is the United Kingdom's naval warfare force. Although warships were used by the English kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years War against the Kingdom of France; the modern Royal Navy traces its origins to the early 16th century. From the middle decades of the 17th century, through the 18th century, the Royal Navy vied with the Dutch Navy and with the French Navy for maritime supremacy. From the mid 18th century, it was the world's most powerful navy until surpassed by the United States Navy during the Second World War; the Royal Navy played a key part in establishing the British Empire as the unmatched world power during the 19th and first part of the 20th centuries. Due to this historical prominence, it is common among non-Britons, to refer to it as "the Royal Navy" without qualification. Following World War I, the Royal Navy was reduced in size, although at the onset of World War II it was still the world's largest.
By the end of the war, the United States Navy had emerged as the world's largest. During the Cold War, the Royal Navy transformed into a anti-submarine force, hunting for Soviet submarines and active in the GIUK gap. Following the collapse of the Soviet Union, its focus has returned to expeditionary operations around the world and remains one of the world's foremost blue-water navies. However, 21st century reductions in naval spending have led to a personnel shortage and a reduction in the number of warships; the Royal Navy maintains a fleet of technologically sophisticated ships and submarines including two aircraft carriers, two amphibious transport docks, four ballistic missile submarines, six nuclear fleet submarines, six guided missile destroyers, 13 frigates, 13 mine-countermeasure vessels and 22 patrol vessels. As of November 2018, there are 74 commissioned ships in the Royal Navy, plus 12 ships of the Royal Fleet Auxiliary; the RFA replenishes Royal Navy warships at sea, augments the Royal Navy's amphibious warfare capabilities through its three Bay-class landing ship vessels.
It works as a force multiplier for the Royal Navy doing patrols that frigates used to do. The total displacement of the Royal Navy is 408,750 tonnes; the Royal Navy is part of Her Majesty's Naval Service, which includes the Royal Marines. The professional head of the Naval Service is the First Sea Lord, an admiral and member of the Defence Council of the United Kingdom; the Defence Council delegates management of the Naval Service to the Admiralty Board, chaired by the Secretary of State for Defence. The Royal Navy operates three bases in the United Kingdom; as the seaborne branch of HM Armed Forces, the RN has various roles. As it stands today, the RN has stated its 6 major roles as detailed below in umbrella terms. Preventing Conflict – On a global and regional level Providing Security At Sea – To ensure the stability of international trade at sea International Partnerships – To help cement the relationship with the United Kingdom's allies Maintaining a Readiness To Fight – To protect the United Kingdom's interests across the globe Protecting the Economy – To safe guard vital trade routes to guarantee the United Kingdom's and its allies' economic prosperity at sea Providing Humanitarian Aid – To deliver a fast and effective response to global catastrophes The strength of the fleet of the Kingdom of England was an important element in the kingdom's power in the 10th century.
At one point Aethelred II had an large fleet built by a national levy of one ship for every 310 hides of land, but it is uncertain whether this was a standard or exceptional model for raising fleets. During the period of Danish rule in the 11th century, the authorities maintained a standing fleet by taxation, this continued for a time under the restored English regime of Edward the Confessor, who commanded fleets in person. English naval power declined as a result of the Norman conquest. Following the Battle of Hastings, the Norman navy that brought over William the Conqueror disappeared from records due to William receiving all of those ships from feudal obligations or because of some sort of leasing agreement which lasted only for the duration of the enterprise. More troubling, is the fact that there is no evidence that William adopted or kept the Anglo-Saxon ship mustering system, known as the scipfryd. Hardly noted after 1066, it appears that the Normans let the scipfryd languish so that by 1086, when the Doomsday Book was completed, it had ceased to exist.
According to the Anglo-Saxon Chronicle, in 1068, Harold Godwinson's sons Godwine and Edmund conducted a ‘raiding-ship army’ which came from Ireland, raiding across the region and to the townships of Bristol and Somerset. In the following year of 1069, they returned with a bigger fleet which they sailed up the River Taw before being beaten back by a local earl near Devon. However, this made explicitly clear that the newly conquered England under Norman rule, in effect, ceded the Irish Sea to the Irish, the Vikings of Dublin, other Norwegians. Besides ceding away the Irish Sea, the Normans ceded the North Sea, a major area where Nordic peoples traveled. In 1069, this lack of naval presence in the North Sea allowed for the invasion an
A finery forge is a forge used to produce wrought iron, from pig iron by decarburization. The process involved liquifying cast iron in a fining hearth and removing carbon from the molten cast iron through oxidation. Finery forges were used as early as 3rd century BC, based on archaeological evidence found at a site in Tieshengguo, China; the finery forge process was replaced by the puddling process and the roller mill, both developed by Henry Cort in 1783-4, but not becoming widespread until after 1800. A finery forge was used to refine wrought iron at least by the 3rd century BC in ancient China, based on the earliest archaeological specimens of cast and pig iron fined into wrought iron and steel found at the early Han Dynasty site at Tieshengguo. Pigott speculates that the finery forge existed in the previous Warring States period, because of the wrought iron items from China dating to that period and there was no documented evidence of the bloomery being used in China. Wagner writes that in addition to the Han Dynasty hearths believed to be fining hearths, there is pictoral evidence of the fining hearth from a Shandong tomb mural dated 1st to 2nd century AD, as well as a hint of written evidence in the 4th century AD Daoist text Taiping Jing.
In Europe, the concept of the finery forge may have been evident as early as the 13th century. However, it was not capable of being used to fashion plate armor until the 15th century, as described in conjunction with the waterwheel-powered blast furnace by the Florentine Italian engineer Antonio Averlino; the finery forge process began to be replaced in Europe from the late 18th century by others, of which puddling was the most successful, though some continued in use through the mid-19th century. The new methods used mineral fuel, freed the iron industry from its dependence on wood to make charcoal. There were several types of finery forges; the dominant type in Sweden was the German forge, which had a single hearth, used for all processes. In Swedish Uppland north of Stockholm and certain adjacent provinces, another kind known as the Walloon forge was used for the production of a pure kind of iron known as oregrounds iron, exported to England to make blister steel, its purity depended on the use of ore from the Dannemora mine.
The Walloon forge was the only kind used in Great Britain. The forge had two kinds of hearths, the finery to finish the product and the chafery to reheat the bloom, the raw material of the process. In the finery, a workman known as the "finer" remelted pig iron so as to oxidise the carbon; this produced a lump of iron known as a bloom. This was returned to the finery; the next stages were undertaken by the "hammerman", who in some iron-making areas such as South Yorkshire was known as the "stringsmith", who heated his iron in a string-furnace. Because the bloom is porous, its open spaces are full of slag, the hammerman's or stringsmith's tasks were to beat the heated bloom with a hammer to drive the molten slag out of it, to draw the product out into a bar to produce what was known as anconies or bar iron. In order to do this, he had to reheat the iron; the fuel used in the finery had to be charcoal, as impurities in any mineral fuel would affect the quality of the iron. The waste product was allowed to cool in the hearth and removed as a "mosser".
In the Furness district they were left as the capstone of a wall near Spark Bridge and Nibthwaite forges. H. Schubert, History of British Iron and Steel Industry c.450 BC to AD 1775, 272–291. A. den Ouden, "The Production of Wrought Iron in Finery Hearths", Historical Metallurgy 15, 63–87 and 16, 29–33. K-G. Hildebrand, Swedish Iron in the Seventeenth and Eighteenth Centuries: Export Industry Before Industrialization. P. King,'The Cartel in Oregrounds Iron: Trading in the Raw Material for Steel During the 18th century", Journal of Industrial History 6, 25–48
A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals pig iron, but others such as lead or copper. Blast refers to the combustion air being "forced" or supplied above atmospheric pressure. In a blast furnace, fuel and flux are continuously supplied through the top of the furnace, while a hot blast of air is blown into the lower section of the furnace through a series of pipes called tuyeres, so that the chemical reactions take place throughout the furnace as the material falls downward; the end products are molten metal and slag phases tapped from the bottom, waste gases exiting from the top of the furnace. The downward flow of the ore and flux in contact with an upflow of hot, carbon monoxide-rich combustion gases is a countercurrent exchange and chemical reaction process. In contrast, air furnaces are aspirated by the convection of hot gases in a chimney flue. According to this broad definition, bloomeries for iron, blowing houses for tin, smelt mills for lead would be classified as blast furnaces.
However, the term has been limited to those used for smelting iron ore to produce pig iron, an intermediate material used in the production of commercial iron and steel, the shaft furnaces used in combination with sinter plants in base metals smelting. Cast iron has been found in China dating to the 5th century BC, but the earliest extant blast furnaces in China date to the 1st century AD and in the West from the High Middle Ages, they spread from the region around Namur in Wallonia in the late 15th century, being introduced to England in 1491. The fuel used in these was invariably charcoal; the successful substitution of coke for charcoal is attributed to English inventor Abraham Darby in 1709. The efficiency of the process was further enhanced by the practice of preheating the combustion air, patented by Scottish inventor James Beaumont Neilson in 1828. Archaeological evidence shows that bloomeries appeared in China around 800 BC, it was thought that the Chinese started casting iron right from the beginning, but this theory has since been debunked by the discovery of'more than ten' iron digging implements found in the tomb of Duke Jing of Qin, whose tomb is located in Fengxiang County, Shaanxi.
There is however no evidence of the bloomery in China after the appearance of the blast furnace and cast iron. In China blast furnaces produced cast iron, either converted into finished implements in a cupola furnace, or turned into wrought iron in a fining hearth. Although cast iron farm tools and weapons were widespread in China by the 5th century BC, employing workforces of over 200 men in iron smelters from the 3rd century onward, the earliest extant blast furnaces were built date to the Han Dynasty in the 1st century AD; these early furnaces used phosphorus-containing minerals as a flux. Chinese blast furnaces ranged from around two to ten meters depending on the region; the largest ones were found in modern Sichuan and Guangdong, while the'dwarf" blast furnaces were found in Dabieshan. In construction, they are both around the same level of technological sophistication The effectiveness of the Chinese blast furnace was enhanced during this period by the engineer Du Shi, who applied the power of waterwheels to piston-bellows in forging cast iron.
Donald Wagner suggests that early blast furnace and cast iron production evolved from furnaces used to melt bronze. Though, iron was essential to military success by the time the State of Qin had unified China. Usage of the blast and cupola furnace remained widespread during Tang Dynasties. By the 11th century, the Song Dynasty Chinese iron industry made a switch of resources from charcoal to coke in casting iron and steel, sparing thousands of acres of woodland from felling; this may have happened as early as the 4th century AD. The primary advantage of the early blast furnace was in large scale production and making iron implements more available to peasants. Cast iron is more brittle than wrought iron or steel, which required additional fining and cementation or co-fusion to produce, but for menial activities such as farming it sufficed. By using the blast furnace, it was possible to produce larger quantities of tools such as ploughshares more efficiently than the bloomery. In areas where quality was important, such as warfare, wrought iron and steel were preferred.
Nearly all Han period weapons are made of wrought iron or steel, with the exception of axe-heads, of which many are made of cast iron. Blast furnaces were later used to produce gunpowder weapons such as cast iron bomb shells and cast iron cannons during the Song dynasty; the simplest forge, known as the Corsican, was used prior to the advent of Christianity. Examples of improved bloomeries are the Stückofen or the Catalan forge, which remained until the beginning of the 19th century; the Catalan forge was invented in Catalonia, during the 8th century. Instead of using natural draught, air was pumped in by a trompe, resulting in better quality iron and an increased capacity; this pumping of airstream in with bellows is known as cold blast, it increases the fuel efficiency of the bloomery and improves yield. The Catalan forges can be built bigger than natural draught bloomeries; the oldest known blast furnaces in the West were built in Dürstel in Switzerland, the Märkische Sauerland in Germany, at Lapphyttan in Sweden, where the complex was active between 1205 and 1300.
At Noraskog in the Swedish parish of Järnboås, there have been fou