Propane is a three-carbon alkane with the molecular formula C3H8. It compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is used as a fuel. Propane is one of a group of liquefied petroleum gases; the others include butane, butadiene, butylene and mixtures thereof. Propane was discovered by the French chemist Marcellin Berthelot in 1857, it was first identified as a volatile component in gasoline by Walter O. Snelling of the U. S. Bureau of Mines in 1910. Although the compound was known long before this, Snelling's work was the beginning of the propane industry in the United States; the volatility of these lighter hydrocarbons caused them to be known as "wild" because of the high vapor pressures of unrefined gasoline. On March 31, 1912, The New York Times reported on Snelling's work with liquefied gas, saying "a steel bottle will carry enough gas to light an ordinary home for three weeks", it was during this time that Snelling, in cooperation with Frank P. Peterson, Chester Kerr, Arthur Kerr, created ways to liquefy the LP gases during the refining of gasoline.
Together, they established American Gasol Co. the first commercial marketer of propane. Snelling had produced pure propane by 1911, on March 25, 1913, his method of processing and producing LP gases was issued patent #1,056,845. A separate method of producing LP gas through compression was created by Frank Peterson and its patent granted on July 2, 1912; the 1920s saw increased production of LP gas, with the first year of recorded production totaling 223,000 US gallons in 1922. In 1927, annual marketed LP gas production reached 1 million US gallons, by 1935, the annual sales of LP gas had reached 56 million US gallons. Major industry developments in the 1930s included the introduction of railroad tank car transport, gas odorization, the construction of local bottle-filling plants; the year 1945 marked the first year. By 1947, 62% of all U. S. homes had been equipped with either natural propane for cooking. In 1950, 1,000 propane-fueled buses were ordered by the Chicago Transit Authority, by 1958, sales in the U.
S. had reached 7 billion US gallons annually. In 2004, it was reported to be a growing $8-billion to $10-billion industry with over 15 billion US gallons of propane being used annually in the U. S; the "prop-" root found in "propane" and names of other compounds with three-carbon chains was derived from "propionic acid", which in turn was named after the Greek words protos and pion. Propane is produced as a by-product of two other processes, natural gas processing and petroleum refining; the processing of natural gas involves removal of butane and large amounts of ethane from the raw gas, in order to prevent condensation of these volatiles in natural gas pipelines. Additionally, oil refineries produce some propane as a by-product of cracking petroleum into gasoline or heating oil; the supply of propane cannot be adjusted to meet increased demand, because of the by-product nature of propane production. About 90% of U. S. propane is domestically produced. The United States imports about 10% of the propane consumed each year, with about 70% of that coming from Canada via pipeline and rail.
The remaining 30% of imported propane comes to the United States from other sources via ocean transport. After it is separated from the crude oil, North American propane is stored in huge salt caverns. Examples of these are Alberta; these salt caverns were hollowed out in the 1940s, they can store 80,000,000 barrels or more of propane. When the propane is needed, much of it is shipped by pipelines to other areas of the United States; the North American standard grade of automotive use propane is rated HD 5. HD 5 grade has a maximum of 5 percent butane, but propane sold in Europe, has a max allowable amount of butane of 30 percent, meaning it's not the same fuel as HD 5; the LPG used as auto fuel and cooking gas in Asia and Australia has a high content of butane. Propane is shipped by truck, ship and railway to many U. S. areas. Propane can be produced as a biofuel. Biopropane is commercially sold in Europe. Propane undergoes combustion reactions in a similar fashion to other alkanes. In the presence of excess oxygen, propane burns to form carbon dioxide.
When not enough oxygen or too much oxygen is present for complete combustion, incomplete combustion occurs, allowing carbon monoxide and/or soot to be formed as well: Complete combustion of propane produces about 50 MJ/kg of heat. Propane combustion is much cleaner than that of unleaded gasoline. Propane per BTU production of CO2 is as low as that of natural gas. Propane burns hotter than home heating oil or diesel fuel because of the high hydrogen content; the presence of C–C bonds, plus the multiple bonds of propylene and butylene, create organic exhausts besides carbon dioxide and water vapor during typical combustion. These bonds cause propane to burn with a visible flame; the enthalpy of combustion of propane gas where all products return to standard state, for example where water returns to its liquid state at standard temperature, is kJ/mol, or MJ/kg. The enthalpy of combustion of propane gas where products do not return to standard state, for example where the hot gases including water vapor exit a chimney, is −2043.455 kJ/mol.
The lower heat value is the amount of heat available from burning the substance where
A great hall is the main room of a royal palace, nobleman's castle or a large manor house or hall house in the Middle Ages, continued to be built in the country houses of the 16th and early 17th centuries, although by the family used the great chamber for eating and relaxing. At that time the word "great" meant big, had not acquired its modern connotations of excellence. In the medieval period the room would have been referred to as the "hall", unless the building had a secondary hall, but the term "great hall" has been predominant for surviving rooms of this type for several centuries, to distinguish them from the different type of hall found in post-medieval houses. Great halls were found in France and Scotland, but similar rooms were found in some other European countries. A typical great hall was a rectangular room between one and a half and three times as long as it was wide, higher than it was wide, it was entered through a screens passage at one end, had windows on one of the long sides including a large bay window.
There was a minstrels' gallery above the screens passage. At the other end of the hall was the dais where the high table was situated; the lord's family's more private rooms lay beyond the dais end of the hall, the kitchen and pantry were on the opposite side of the screens passage. Royal and noble residences had few living rooms until late in the Middle Ages, a great hall was a multifunctional room, it was used for receiving guests and it was the place where the household would dine together, including the lord of the house, his gentleman attendants and at least some of the servants. At night some members of the household might sleep on the floor of the great hall; the hall would have had a central hearth, with the smoke rising through the hall to a vent in the roof. The hearth was used for heating and for some of the cooking, although for larger structures a medieval kitchen would customarily lie on a lower level for the bulk of cooking; the fireplace would have an elaborate overmantel with stone or wood carvings or plasterwork which might contain coats of arms, heraldic mottoes, caryatids or other adornment.
In the upper halls of French manor houses, the fireplaces were very large and elaborate. The great hall had the most beautiful decorations in it, as well as on the window frame mouldings on the outer wall. Many French manor houses have beautifully decorated external window frames on the large mullioned windows that light the hall; this decoration marked the window as belonging to the lord's private hall. It was. In Scotland, six common furnishings were present in the sixteenth century hall: the high table and principal seat. In western France, the early manor houses were centered on a central ground-floor hall; the hall reserved for the lord and his high-ranking guests was moved up to the first-floor level. This was called upper hall. In some of the larger three-storey manor houses, the upper hall was as high as second storey roof; the smaller ground-floor hall or salle basse remained but was for receiving guests of any social order. It is common to find these two halls superimposed, one on top of the other, in larger manor houses in Normandy and Brittany.
Access from the ground-floor hall to the upper hall was via an external staircase tower. The upper hall contained the lord's bedroom and living quarters off one end; the great hall would have an early listening device system, allowing conversations to be heard in the lord's bedroom above. In Scotland these devices are called a laird's lug. In many French manor houses there are small peep-holes from which the lord could observe what was happening in the hall; this type of hidden peep-hole is called a judas in French. Many great halls survive. Two large surviving royal halls are Westminster Hall and the Vladislav Hall in Prague Castle. Penshurst Place in Kent, England has a little altered 14th century example. Surviving 16th and early 17th century specimens in England and Scotland are numerous, for example those at Longleat, Burghley House, Bodysgallen Hall, Muchalls Castle and Crathes Castle; the greater centralization of power in royal hands meant that men of good social standing were less inclined to enter the service of a lord to obtain his protection, the size of the inner household shrank.
As the social gap between master and servant grew, the family retreated to the 1st floor, to private rooms. In fact, servants were not allowed to use the same staircases as nobles to access the great hall of larger castles in early times; the other living rooms in country houses became more numerous and important, by the late 17th century the halls of many new houses were vestibules, passed through to get to somewhere else, but not lived in. Other great halls like that at Bank Hall in Lancashire were downsized to create two rooms; the domestic model applied to Collegiate institutions du
A bellows or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an airtight cavity which can be expanded and contracted by operating the handles, fitted with a valve allowing air to fill the cavity when expanded, with a tube through which the air is forced out in a stream when the cavity is compressed, it has many applications, in particular blowing on a fire to supply it with air. The term "bellows" is used by extension for a flexible bag whose volume can be changed by compression or expansion, but not used to deliver air. For example, the light-tight bag allowing the distance between the lens and film of a folding photographic camera to be varied is called a bellows. "Bellows" is only used in plural. The Old English name for'bellows' was blǽstbęlg, blást-bęlg'blast-bag, blowing-bag'; the word is cognate with "belly". There are similar words in Old Norse and Danish, but the derivation is not certain.'Bellows' appears not to be cognate with the similar Latin follis.
Several processes, such as metallurgical iron smelting and welding, require so much heat that they could only be developed after the invention, in antiquity, of the bellows. The bellows are used to deliver additional air to the fuel, raising the rate of combustion and therefore the heat output. Various kinds of bellows are used in metallurgy: Box bellows were and are traditionally used in East Asia. Pot bellows were used in ancient Egypt. Tatara foot bellows from Japan. Accordion bellows, with the characteristic pleated sides, have been used in Europe for many centuries. Piston bellows were developed in the middle of the 18th century in Europe. However, the double action piston bellows were utilised by the Han Chinese in ancient China as early as the 3rd century BC. Metal bellows were made to absorb axial movement in a dynamic condition. Referred to as Axial Dynamics bellows types; the manufacturing of different alloys in China required a continuous stream of air, able to be blown over through molten metals.
The use of double-action piston bellows was described by Chinese philosopher Lao Tzu around 500 BC to produce a continuous stream of air. The Han Dynasty Chinese mechanical engineer Du Shi is credited with being the first to use double-action piston pumps to apply hydraulic power, through a waterwheel, to operate bellows in metallurgy, his invention was used to operate piston bellows of blast furnaces. The ancient Greeks, ancient Romans, other civilizations used bellows in bloomery furnaces producing wrought iron. Bellows are used to send pressurized air in a controlled manner in a fired heater. In modern industry, reciprocating bellows are replaced with motorized blowers. Double-acting piston bellows are a type of bellows used by blacksmiths and smelters to increase the air flow going into the forge, with the property that air is blown out on both strokes of the handle; these bellows blow a more constant, thus stronger, blast than simple bellows. Such bellows existed in China at least since the 5th century BC, when it was invented, had reached Europe by the 16th century.
In 240 BC, The ancient Greek inventor Ctesibius of Alexandria independently invented a double-action piston bellow used to lift water from one level to another. A piston is enclosed in a rectangular box with a handle coming out one side; the piston edges are covered with feathers, fur, or soft paper to ensure that it is airtight and lubricated. As the piston is pulled, air from one side enters and flows through the nozzle and as it is pushed air enters from the opposite side and flows through the same nozzle; these have three leaves. The middle leaf is fixed in place; the bottom leaf is moved down. The top leaf can move and has a weight on it; the bottom and the middle leaves contain valves, the top one does not. Only the top lung is connected to the spout; when the bottom leaf is moved up, air is pumped from the bottom lung into the top lung. At the same time air is leaving the bellows from the top lung through the spout, but at a slower rate; this inflates the top lung. Next the bottom leaf is moved down to pull fresh air into the bellows.
While this happens the weight on the top leaf pushes it down, so air keeps leaving through the spout. This design does not increase the amount of air flow going into the forge, but provides a more constant air flow compared to a simple bellows, it provides more air flow than two simple bellows pumped alternately or one double-acting piston bellows. Bellows are used extensively in cooling loops, they are an essential part of anesthesia machines. Bellows PTFE with cone and socket for ground glass joints. Cuckoo clocks use bellows to blow air through their gedackt and imitate the call of the Common Cuckoo bird. Musical instruments may employ bellows as a substitute or regulator for air pressure provided by the human lungs: melodeon and related instruments Reed organ Pipe organ Musette de cour and some other varieties of bagpipes Harmonium and melodeon Portative The term "bellows" is used by extension for a number of applications that do not involve air transfer. Bellows are used in industrial and mechanical applications such as rod boots, machinery way covers, lift covers and rail covers to protect rods and seals from dirt.
Bellows are used on articulated buses and trams, to cove
Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air, entrained or otherwise mixed into the mass. It is an unwanted by-product of fires, but may be used for pest control, communication and offensive capabilities in the military, cooking, or smoking, it is used in rituals where incense, sage, or resin is burned to produce a smell for spiritual purposes. Smoke is sometimes used as a flavoring agent, preservative for various foodstuffs. Smoke is a component of internal combustion engine exhaust gas diesel exhaust. Smoke inhalation is the primary cause of death in victims of indoor fires; the smoke kills by a combination of thermal damage and pulmonary irritation caused by carbon monoxide, hydrogen cyanide and other combustion products. Smoke is an aerosol of solid particles and liquid droplets that are close to the ideal range of sizes for Mie scattering of visible light; this effect has been likened to three-dimensional textured privacy glass — a smoke cloud does not obstruct an image, but scrambles it.
The composition of smoke depends on the nature of the conditions of combustion. Fires with high availability of oxygen burn at a high temperature and with small amount of smoke produced. High temperature leads to production of nitrogen oxides. Sulfur content yields sulfur dioxide. Carbon and hydrogen are completely oxidized to carbon dioxide and water. Fires burning with lack of oxygen produce a wider palette of compounds, many of them toxic. Partial oxidation of carbon produces carbon monoxide, nitrogen-containing materials can yield hydrogen cyanide and nitrogen oxides. Hydrogen gas can be produced instead of water. Content of halogens such as chlorine may lead to production of e.g. hydrogen chloride, phosgene and chloromethane, bromomethane and other halocarbons. Hydrogen fluoride can be formed from fluorocarbons, whether fluoropolymers subjected to fire or halocarbon fire suppression agents. Phosphorus and antimony oxides and their reaction products can be formed from some fire retardant additives, increasing smoke toxicity and corrosivity.
Pyrolysis of polychlorinated biphenyls, e.g. from burning older transformer oil, to lower degree of other chlorine-containing materials, can produce 2,3,7,8-tetrachlorodibenzodioxin, a potent carcinogen, other polychlorinated dibenzodioxins. Pyrolysis of fluoropolymers, e.g. teflon, in presence of oxygen yields carbonyl fluoride. Pyrolysis of burning material incomplete combustion or smoldering without adequate oxygen supply results in production of a large amount of hydrocarbons, both aliphatic and aromatic, terpenes. Heterocyclic compounds may be present. Heavier hydrocarbons may condense as tar. Presence of such smoke, and/or brown oily deposits during a fire indicates a possible hazardous situation, as the atmosphere may be saturated with combustible pyrolysis products with concentration above the upper flammability limit, sudden inrush of air can cause flashover or backdraft. Presence of sulfur can lead to formation of e.g. hydrogen sulfide, carbonyl sulfide, sulfur dioxide, carbon disulfide, thiols.
Partial oxidation of the released hydrocarbons yields in a wide palette of other compounds: aldehydes, alcohols, carboxylic acids. The visible particulate matter in such smokes is most composed of carbon. Other particulates may be composed of solid particles of ash; the presence of metals in the fuel yields particles of metal oxides. Particles of inorganic salts may be formed, e.g. ammonium sulfate, ammonium nitrate, or sodium chloride. Inorganic salts present on the surface of the soot particles may make them hydrophilic. Many organic compounds the aromatic hydrocarbons, may be adsorbed on the surface of the solid particles. Metal oxides can be present when metal-containing fuels are burned, e.g. solid rocket fuels containing aluminium. Depleted uranium projectiles after impacting the target ignite, producing particles of uranium oxides. Magnetic particles, spherules of magnetite-like ferrous ferric oxide, are present in coal smoke. Magnetic remanence, recorded in the iron oxide particles, indicates the strength of Earth's magnetic field when they were cooled beyond their Curie temperature.
Fly ash is composed of silica and calcium oxide. Cenospheres are present in smoke from liquid hydrocarbon fu
A chimney is an architectural ventilation structure made of masonry, clay or metal that isolates hot toxic exhaust gases or smoke produced by a boiler, furnace, incinerator or fireplace from human living areas. Chimneys are vertical, or as near as possible to vertical, to ensure that the gases flow smoothly, drawing air into the combustion in what is known as the stack, or chimney effect; the space inside a chimney is called the flue. Chimneys are adjacent to large industrial refineries, fossil fuel combustion facilities or part of buildings, steam locomotives and ships. In the United States, the term'Smokestack industry' refers to the environmental impacts of burning fossil fuels by industrial society including the electric industry during its earliest history; the term smokestack is used when referring to locomotive chimneys or ship chimneys, the term funnel can be used. The height of a chimney influences its ability to transfer flue gases to the external environment via stack effect. Additionally, the dispersion of pollutants at higher altitudes can reduce their impact on the immediate surroundings.
The dispersion of pollutants over a greater area can reduce their concentrations and facilitate compliance with regulatory limits. Romans used tubes inside the walls to draw smoke out of bakeries but chimneys only appeared in large dwellings in northern Europe in the 12th century; the earliest extant example of an English chimney is at the keep of Conisbrough Castle in Yorkshire, which dates from 1185 AD. However, they did not become common in houses until the 17th centuries. Smoke hoods were an early method of collecting the smoke into a chimney. Another step in the development of chimneys was the use of built in ovens which allowed the household to bake at home. Industrial chimneys became common in the late 18th century. Chimneys in ordinary dwellings were first built of plaster or mud. Since chimneys have traditionally been built of brick or stone, both in small and large buildings. Early chimneys were of a simple brick construction. Chimneys were constructed by placing the bricks around tile liners.
To control downdrafts, venting caps with a variety of designs are sometimes placed on the top of chimneys. In the 18th and 19th centuries, the methods used to extract lead from its ore produced large amounts of toxic fumes. In the north of England, long near-horizontal chimneys were built more than 3 km long, which terminated in a short vertical chimney in a remote location where the fumes would cause less harm. Lead and silver deposits formed on the inside of these long chimneys, periodically workers would be sent along the chimneys to scrape off these valuable deposits; as a result of the limited ability to handle transverse loads with brick, chimneys in houses were built in a "stack", with a fireplace on each floor of the house sharing a single chimney with such a stack at the front and back of the house. Today's central heating systems have made chimney placement less critical, the use of non-structural gas vent pipe allows a flue gas conduit to be installed around obstructions and through walls.
In fact, most modern high-efficiency heating appliances do not require a chimney. Such appliances are installed near an external wall, a noncombustible wall thimble allows a vent pipe to run directly through the external wall. On a pitched roof where a chimney penetrates a roof, flashing is used to seal up the joints; the down-slope piece is called an apron, the sides receive step flashing and a cricket is used to divert water around the upper side of the chimney underneath the flashing. Industrial chimneys are referred to as flue gas stacks and are external structures, as opposed to those built into the wall of a building, they are located adjacent to a steam-generating boiler or industrial furnace and the gases are carried to them with ductwork. Today the use of reinforced concrete has entirely replaced brick as a structural component in the construction of industrial chimneys. Refractory bricks are used as a lining if the type of fuel being burned generates flue gases containing acids. Modern industrial chimneys sometimes consist of a concrete windshield with a number of flues on the inside.
The 300 m chimney at Sasol Three consists of a 26 m diameter windshield with four 4.6 metre diameter concrete flues which are lined with refractory bricks built on rings of corbels spaced at 10 metre intervals. The reinforced concrete can be sliding formwork; the height is to ensure the pollutants are dispersed over a wider area to meet legal or other safety requirements. A flue liner is a secondary barrier in a chimney that protects the masonry from the acidic products of combustion, helps prevent flue gas from entering the house, reduces the size of an oversized flue. Since the 1950s, building codes in many locations require newly built chimneys to have a flue liner. Chimneys built without a liner can have a liner added, but the type of liner needs to match the type of appliance it services. Flue liners may be concrete tile, metal, or poured in place concrete. Clay tile flue liners are common in the United States, although it is the only liner that does not meet Underwriters Laboratories 1777 approval and they have problems such as cracked tiles and improper installation.
Clay tiles are about 2 feet long, available in various sizes and shapes, are installed in new construction as the chimney is built. A refractory cement is used between each tile. Metal liners may be stainless steel, aluminum, or galvanized iron and may be flexible or rigid pipes. Stainless stee
A spark arrester is any device which prevents the emission of flammable debris from combustion sources, such as internal combustion engines and wood burning stoves. Spark arresters play a critical role in the prevention of wildland fire and ignition of explosive atmospheres, their use is required by law in many jurisdictions worldwide. Spark arresters for steam locomotives may be external; the earliest platforms for spark arresters in the United States were steam locomotives. Wood- and coal-burning locomotives produce embers which are transported by the wind. One popular design was the Radley-Hunter spark arrester, which used a spiral-shaped cone to separate embers from the exhaust flow by centrifugal force; the problem of equipment-started fires continued into the 20th century. University of California, Berkeley researchers J. P. Fairbank and Roy Bainer provided the first known academic research on the subject, their experiments demonstrated that hot particulate matter larger than 0.023 inches in diameter was capable of igniting wildland fuels.
In the 1950s, the United States Forest Service became interested in reducing the number of fires started by logging equipment in the National Forest System. This interest led to a partnership with the Society of Automotive Engineers and the development of the following test standards for spark arresters: SAE J335 – Multiposition Small Engine Exhaust System Fire Ignition Suppression SAE J342 – Spark Arrester Test Procedure for Large Size Engines SAE J350 – Spark Arrester Test Procedure for Medium Size EnginesModern technologies have eliminated the production of large particulate matter from internal combustion engines. However, as engines wear, carbon deposits can build up on the internal walls of the engine; when these deposits break free, they exit through the exhaust system and present a potential fire hazard. Vehicles without properly functioning spark arresters have been suspected of starting numerous wildfires, including the devastating track fire near Raton, New Mexico in June 2011. Today, spark arresters can be found as OEM or aftermarket components on many types of equipment, such as large agricultural machines, off highway vehicles, small engines.
Spark arresters are fitted to the top of a flue to prevent floating embers from a fire setting light to a flammable roofing surface or falling onto combustible material on the ground. Such a spark arrester consists of a double layer of metal mesh, which catches the ember and allows the flue gas to escape. Large power station boilers are fitted with electrostatic precipitators. Centrifugal type spark arresters employ stationary vanes, baffles, or other devices to trap large particles by centrifugal force; these spark arresters are found on heavy agricultural and construction equipment, but some have been developed for motorcycles and other all-terrain vehicles. Screen type spark arresters use a physical mesh to prevent large particles from leaving the exhaust system; this is the most common type of spark arrester. Screen type devices are used on most motorcycles, ATVs, small engines. Laws governing spark arrester use in the United States depend on the jurisdiction. Internal combustion engines operating on USDA Forest Service and most other federally managed lands must meet the requirements of the Code of Federal Regulations 36 CFR 261.52.
This mandate requires the operator to have a certified and properly maintained spark arrester installed at all times. Many state and local land management agencies defer to the federal requirement. Exemptions exist for automobiles registered with their state's department of motor vehicles. During periods of extreme fire danger, land managers may prevent the use of all motorized equipment if a properly functioning spark arrester is installed. Spark arrester inspections are performed by trained agency law enforcement or fire prevention personnel, they may occur on an individual basis, or as part of an inspection checkpoint during busy recreation weekends. Operators caught using unqualified or modified devices could be cited. Penalties for violating spark arrester laws depend on the issuing agency. If it is determined a noncompliant vehicle was responsible for starting a fire, the operator could be held liable in civil or criminal court. Certification testing of spark arresters is performed by the USDA Forest Service Technology and Development Center in San Dimas, CA.
The technical requirements are outlined in Forest Service Specification FS5100-1. All spark arresters meeting the requirements of 36 CFR 261.52 must be certified and listed in the USDA Forest Service Spark Arrester Guide. This guide is a comprehensive directory of all qualified products available in the United States, is published biannually; the Spark Arrester Guide is used by field inspectors and consumers to verify product certification status. Manufacturers pursuing spark arrester qualification in the United States should consult the USDA Forest Service's "Manufacturer's Submission Procedure" for both general purpose and small engine spark arresters. Flame arrester Off-Highway Vehicle Spark Arresters Tech Tip General Purpose Spark Arresters Tech Tip Spark Arrester Law - State of California
The fireplace mantel or mantelpiece known as a chimneypiece, originated in medieval times as a hood that projected over a fire grate to catch the smoke. The term has evolved to include the decorative framework around the fireplace, can include elaborate designs extending to the ceiling. Mantelpiece is now the general term for the jambs, mantel shelf, external accessories of a fireplace. For many centuries, the chimneypiece was the most ornamental and most artistic feature of a room, but as fireplaces have become smaller, modern methods of heating have been introduced, its artistic as well as its practical significance has lessened. Up to the twelfth century, fires were made in the middle of a home by a hypocaust, or with braziers, or by fires on the hearth with smoke vented out through the lantern in the roof; as time went on, the placement of fireplaces moved to the wall, incorporating chimneys to vent the smoke. This permitted the design of a elaborate, architectural focal point for a grand room.
At a date, in consequence of the greater width of the fireplace, flat or segmental arches were thrown across and constructed with archivolt, sometimes joggled, with the thrust of the arch being resisted by bars of iron at the back. In domestic work of the fourteenth century, the chimneypiece was increased in order to allow of the members of the family sitting on either side of the fire on the hearth, in these cases great beams of timber were employed to carry the hood; the largest chimneypiece existing is in the great hall of the Palais des Comtes at Poitiers, nearly 30 feet wide, having two intermediate supports to carry the hood. The history of carved mantels is a fundamental element in the history of western art; every element of European sculpture can be seen on great mantels. Many of the noted sculptors of the past i.e. Augustus St. Gaudens designed and carved magnificent mantels, some of which can be found on display in the worlds great museums; as the facade of a building is distinguished by its design and detail so it is with fine mantels.
The attention to carved detail is. Up until the 20th century and the invention of mechanized contained heating systems, rooms were heated by an open or central fire. A modern fireplace serves as an element to enhance the grandeur of an interior space rather than as a heat source. Today, fireplaces of varying quality and style are available worldwide; the fireplace mantels of today incorporate the architecture of two or more periods or cultures. In the early Renaissance style, the chimneypiece of the Palais de Justice at Bruges is a magnificent example; the most prolific modern designer of chimneypieces was G. B. Piranesi, who in 1765 published a large series, on which at a date the Empire style in France was based. In France, the finest work of the early Renaissance period is to be found in the chimneypieces, which are of infinite variety of design; the English chimneypieces of the early seventeenth century, when the purer Italian style was introduced by Inigo Jones, were simple in design, sometimes consisting only of the ordinary mantel piece, with classic architraves and shelf, the upper part of the chimney breast being paneled like the rest of the room.
In the latter part of the century the classic architrave was abandoned in favor of a much bolder and more effective molding, as in the chimneypieces at Hampton Court, the shelf was omitted. In the eighteenth century, the architects returned to the Inigo Jones classic type, but influenced by the French work of Louis XIV. and XV. Figure sculpture represented by graceful figures on each side, which assisted to carry the shelf, was introduced, the over-mantel developed into an elaborate frame for the family portrait over the chimneypiece. Towards the close of the eighteenth century the designs of the Adam Brothers superseded all others, a century they came again into fashion; the Adam mantels are in wood enriched with ornament, cast in molds, sometimes copied from the carved wood decoration of old times. Mantels or fireplace mantels can be the focus of custom interior decoration. A mantel traditionally offers a unique opportunity for the architect/designer to create a personal statement unique to the room they are creating.
The mantel defines the architectural style of the interior decor, whether it be traditional i.e. Classic, Italian, American, Gothic etc; the choice of material for the mantel includes such rich materials as marble, granite, or fine woods. The most luxurious of materials is marble. In the past only the finest of rare colored and white marbles were used. Today many of those fine materials are no longer available, however many other beautiful materials can be found world wide; the defining element of a great mantel is the workmanship. A mantel offers a unique opportunity in its design for a sculptor/artisan to demonstrate their skill in carving each of the fine decorative elements. Elements such as capitals, brackets, animals and vegetation are used to decorate a mantel. One might say. More than the material, it is the quality of the carving that defines the quality of the mantel piece thus highlighting the magnificence of the room. Mantel clock Millwork Staf