1.
Freemasonry
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The degrees of freemasonry retain the three grades of medieval craft guilds, those of Apprentice, Journeyman or fellow, and Master Mason. These are the degrees offered by Craft Freemasonry, members of these organisations are known as Freemasons or Masons. There are additional degrees, which vary with locality and jurisdiction, the basic, local organisational unit of Freemasonry is the Lodge. The Lodges are usually supervised and governed at the level by a Grand Lodge or Grand Orient. There is no international, worldwide Grand Lodge that supervises all of Freemasonry, each Grand Lodge is independent, modern Freemasonry broadly consists of two main recognition groups. Continental Freemasonry is now the term for the liberal jurisdictions who have removed some, or all. The Masonic Lodge is the organisational unit of Freemasonry. The Lodge meets regularly to conduct the formal business of any small organisation. In addition to business, the meeting may perform a ceremony to confer a Masonic degree or receive a lecture, at the conclusion of the meeting, the Lodge might adjourn for a formal dinner, or festive board, sometimes involving toasting and song. The bulk of Masonic ritual consists of degree ceremonies, candidates for Freemasonry are progressively initiated into Freemasonry, first in the degree of Entered Apprentice. Some time later, in a ceremony, they will be passed to the degree of Fellowcraft. In all of ceremonies, the candidate is entrusted with passwords, signs. Another ceremony is the installation of the Master and officers of the Lodge. In some jurisdictions Installed Master is valued as a separate rank, in other jurisdictions, the grade is not recognised, and no inner ceremony conveys new secrets during the installation of a new Master of the Lodge. Most Lodges have some sort of calendar, allowing Masons. Often coupled with events is the obligation placed on every Mason to contribute to charity. This occurs at both Lodge and Grand Lodge level, Masonic charities contribute to many fields from education to disaster relief. These private local Lodges form the backbone of Freemasonry, and a Freemason will necessarily have been initiated into one of these, there also exist specialist Lodges where Masons meet to celebrate anything from sport to Masonic research
2.
Mortar (masonry)
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In its broadest sense mortar includes pitch, asphalt, and soft mud or clay, such as used between mud bricks. Mortar comes from Latin mortarium meaning crushed, mortars are typically made from a mixture of sand, a binder, and water. The most common binder since the early 20th century is Portland cement, there are several types of cement mortars and additives. The first mortars were made of mud and clay, because of a lack of stone and an abundance of clay, Babylonian constructions were of baked brick, using lime or pitch for mortar. According to Roman Ghirshman, the first evidence of using a form of mortar was at the Mehrgarh of Baluchistan in Pakistan. The ancient sites of Harappan civilization of third millennium BCE are built with kiln-fired bricks, gypsum mortar, also called plaster of Paris, was used in the construction of the Egyptian pyramids and many other ancient structures. It is made from gypsum, which requires a firing temperature. It is therefore easier to make lime mortar and sets up much faster which may be a reason it was used as the typical mortar in ancient, brick arch. Gypsum mortar is not as durable as other mortars in damp conditions, in early Egyptian pyramids, which were constructed during the Old Kingdom, the limestone blocks were bound by mortar of mud and clay, or clay and sand. In later Egyptian pyramids, the mortar was made of gypsum or lime. Gypsum mortar was essentially a mixture of plaster and sand and was quite soft, in the Indian subcontinent, multiple cement types have been observed in the sites of the Indus Valley Civilization, such as the Mohenjo-daro city-settlement that dates to earlier than 2600 BCE. Bitumen mortar was used at a lower-frequency, including in the Great Bath at Mohenjo-daro. Historically, building with concrete and mortar next appeared in Greece, the excavation of the underground aqueduct of Megara revealed that a reservoir was coated with a pozzolanic mortar 12 mm thick. This aqueduct dates back to c.500 BCE, pozzolanic mortar is a lime based mortar, but is made with an additive of volcanic ash that allows it to be hardened underwater, thus it is known as hydraulic cement. The Greeks obtained the volcanic ash from the Greek islands Thira and Nisiros, or from the then Greek colony of Dicaearchia near Naples, the Romans later improved the use and methods of making what became known as pozzolanic mortar and cement. Even later, the Romans used a mortar without pozzolana using crushed terra cotta, introducing aluminum oxide and this mortar was not as strong as pozzolanic mortar, but, because it was denser, it better resisted penetration by water. Hydraulic mortar was not available in ancient China, possibly due to a lack of volcanic ash, around 500 CE, sticky rice soup was mixed with slaked lime to make an inorganic−organic composite mortar that had more strength and water resistance than lime mortar. It is not understood how the art of making hydraulic mortar and cement, during the Middle Ages when the Gothic cathedrals were being built, the only active ingredient in the mortar was lime
3.
Brick
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A brick is building material used to make walls, pavements and other elements in masonry construction. Traditionally, the term referred to a unit composed of clay. A brick can be composed of clay-bearing soil, sand, and lime, Bricks are produced in numerous classes, types, materials, and sizes which vary with region and time period, and are produced in bulk quantities. Two basic categories of bricks are fired and non-fired bricks, block is a similar term referring to a rectangular building unit composed of similar materials, but is usually larger than a brick. Lightweight bricks are made from expanded clay aggregate, fired bricks are one of the longest-lasting and strongest building materials, sometimes referred to as artificial stone, and have been used since circa 5000 BC. Air-dried bricks, also known as mudbricks, have an older than fired bricks. Bricks are laid in courses and numerous patterns known as bonds, collectively known as brickwork, the earliest bricks were dried brick, meaning that they were formed from clay-bearing earth or mud and dried until they were strong enough for use. The oldest discovered bricks, originally made from shaped mud and dating before 7500 BC, were found at Tell Aswad, in the upper Tigris region, ceramic, or fired brick was used as early as 3000 BC in early Indus Valley cities. In pre-modern China, bricks were being used from the 2nd millennium BCE at a site near Xian, the carpenters manual Yingzao Fashi, published in 1103 at the time of the Song dynasty described the brick making process and glazing techniques then in use. He also had to know when to quench the kiln with water so as to produce the surface glaze, Early civilisations around the Mediterranean adopted the use of fired bricks, including the Ancient Greeks and Romans. The Roman legions operated mobile kilns, and built large brick structures throughout the Roman Empire, during the Early Middle Ages the use of bricks in construction became popular in Northern Europe, after being introduced there from Northern-Western Italy. An independent style of architecture, known as brick Gothic flourished in places that lacked indigenous sources of rocks. Examples of this style can be found in modern-day Denmark, Germany, Poland. A clear distinction between the two styles developed at the transition to Baroque architecture. In Lübeck, for example, Brick Renaissance is clearly recognisable in buildings equipped with terracotta reliefs by the artist Statius von Düren, production of bricks increased massively with the onset of the Industrial Revolution and the rise in factory building in England. For reasons of speed and economy, bricks were increasingly preferred as building material to stone and it was at this time in London, that bright red brick was chosen for construction to make the buildings more visible in the heavy fog and to help prevent traffic accidents. The transition from the method of production known as hand-moulding to a mechanised form of mass-production slowly took place during the first half of the nineteenth century. His mechanical apparatus soon achieved widespread attention after it was adopted for use by the South Eastern Railway Company for brick-making at their factory near Folkestone, the Bradley & Craven Ltd ‘Stiff-Plastic Brickmaking Machine’ was patented in 1853, apparently predating Clayton
4.
Rock (geology)
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Rock or stone is a natural substance, a solid aggregate of one or more minerals or mineraloids. For example, granite, a rock, is a combination of the minerals quartz, feldspar. The Earths outer solid layer, the lithosphere, is made of rock, rock has been used by mankind throughout history. The minerals and metals found in rocks have been essential to human civilization, three major groups of rocks are defined, igneous, sedimentary, and metamorphic. The scientific study of rocks is called petrology, which is a component of geology. At a granular level, rocks are composed of grains of minerals, the aggregate minerals forming the rock are held together by chemical bonds. The types and abundance of minerals in a rock are determined by the manner in which the rock was formed, many rocks contain silica, a compound of silicon and oxygen that forms 74. 3% of the Earths crust. This material forms crystals with other compounds in the rock, the proportion of silica in rocks and minerals is a major factor in determining their name and properties. Rocks are geologically classified according to such as mineral and chemical composition, permeability, the texture of the constituent particles. These physical properties are the end result of the processes that formed the rocks, over the course of time, rocks can transform from one type into another, as described by the geological model called the rock cycle. These events produce three general classes of rock, igneous, sedimentary, and metamorphic, the three classes of rocks are subdivided into many groups. However, there are no hard and fast boundaries between allied rocks, hence the definitions adopted in establishing rock nomenclature merely correspond to more or less arbitrary selected points in a continuously graduated series. Igneous rock forms through the cooling and solidification of magma or lava and this magma can be derived from partial melts of pre-existing rocks in either a planets mantle or crust. Typically, the melting of rocks is caused by one or more of three processes, an increase in temperature, a decrease in pressure, or a change in composition, igneous rocks are divided into two main categories, plutonic rock and volcanic. Plutonic or intrusive rocks result when magma cools and crystallizes slowly within the Earths crust, a common example of this type is granite. Volcanic or extrusive rocks result from magma reaching the surface either as lava or fragmental ejecta, the chemical abundance and the rate of cooling of magma typically forms a sequence known as Bowens reaction series. Most major igneous rocks are found along this scale, about 64. 7% of the Earths crust by volume consists of igneous rocks, making it the most plentiful category. Of these, 66% are basalts and gabbros, 16% are granite, only 0. 6% are syenites and 0. 3% peridotites and dunites
5.
Marble
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Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. Geologists use the marble to refer to metamorphosed limestone, however. Marble is commonly used for sculpture and as a building material and this stem is also the basis for the English word marmoreal, meaning marble-like. In Hungarian it is called márvány, Marble is a rock resulting from metamorphism of sedimentary carbonate rocks, most commonly limestone or dolomite rock. Metamorphism causes variable recrystallization of the carbonate mineral grains. The resulting marble rock is composed of an interlocking mosaic of carbonate crystals. Primary sedimentary textures and structures of the carbonate rock have typically been modified or destroyed. Pure white marble is the result of metamorphism of a very pure limestone or dolomite protolith, green coloration is often due to serpentine resulting from originally magnesium-rich limestone or dolostone with silica impurities. These various impurities have been mobilized and recrystallized by the intense pressure, examples of historically notable marble varieties and locations, White marble has been prized for its use in sculptures since classical times. This preference has to do with its softness, which made it easier to carve, relative isotropy and homogeneity, construction marble is a stone which is composed of calcite, dolomite or serpentine which is capable of taking a polish. More generally in construction, specifically the dimension stone trade, the marble is used for any crystalline calcitic rock useful as building stone. For example, Tennessee marble is really a dense granular fossiliferous gray to pink to maroon Ordovician limestone that geologists call the Holston Formation. Ashgabat, the city of Turkmenistan, was recorded in the 2013 Guinness Book of Records as having the worlds highest concentration of white marble buildings. According to the United States Geological Survey, U. S. domestic marble production in 2006 was 46,400 tons valued at about $18.1 million, compared to 72,300 tons valued at $18.9 million in 2005. Crushed marble production in 2006 was 11.8 million tons valued at $116 million, of which 6.5 million tons was finely ground calcium carbonate and the rest was construction aggregate. For comparison,2005 crushed marble production was 7.76 million tons valued at $58.7 million, of which 4.8 million tons was finely ground calcium carbonate, U. S. dimension marble demand is about 1.3 million tons. The DSAN World Demand for Marble Index has shown a growth of 12% annually for the 2000–2006 period, the largest dimension marble application is tile. In 1998, marble production was dominated by 4 countries that accounted for almost half of production of marble
6.
Granite
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Granite is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Granites can be white, pink, or gray in color. The word granite comes from the Latin granum, a grain, in reference to the structure of such a holocrystalline rock. By definition, granite is a rock with at least 20% quartz. The term granitic means granite-like and is applied to granite and a group of igneous rocks with similar textures and slight variations in composition. Occasionally some individual crystals are larger than the groundmass, in case the texture is known as porphyritic. A granitic rock with a texture is known as a granite porphyry. Granitoid is a general, descriptive field term for lighter-colored, coarse-grained igneous rocks, petrographic examination is required for identification of specific types of granitoids. The extrusive igneous rock equivalent of granite is rhyolite, Granite is nearly always massive, hard and tough, and therefore it has gained widespread use throughout human history, and more recently as a construction stone. The average density of granite is between 2.65 and 2.75 g/cm3, its compressive strength usually lies above 200 MPa, and its viscosity near STP is 3–6 •1019 Pa·s. The melting temperature of dry granite at ambient pressure is 1215–1260 °C, it is reduced in the presence of water. Granite has poor primary permeability, but strong secondary permeability, true granite according to modern petrologic convention contains both plagioclase and alkali feldspars. When a granitoid is devoid or nearly devoid of plagioclase, the rock is referred to as alkali feldspar granite, when a granitoid contains less than 10% orthoclase, it is called tonalite, pyroxene and amphibole are common in tonalite. A granite containing both muscovite and biotite micas is called a binary or two-mica granite, two-mica granites are typically high in potassium and low in plagioclase, and are usually S-type granites or A-type granites. A worldwide average of the composition of granite, by weight percent, based on 2485 analyses. Much of it was intruded during the Precambrian age, it is the most abundant basement rock that underlies the relatively thin veneer of the continents. Outcrops of granite tend to form tors and rounded massifs, granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels. Granite often occurs as small, less than 100 km² stock masses
7.
Travertine
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Travertine is a form of limestone deposited by mineral springs, especially hot springs. Travertine often has a fibrous or concentric appearance and exists in white, tan, cream-colored and it is formed by a process of rapid precipitation of calcium carbonate, often at the mouth of a hot spring or in a limestone cave. In the latter, it can form stalactites, stalagmites, and it is frequently used in Italy and elsewhere as a building material. Travertine is a sedimentary rock, formed by the precipitation of carbonate minerals from solution in ground and surface waters. Similar deposits formed from water are known as tufa. The word travertine is derived from the Italian travertino, itself a derivation of the Latin tiburtinus ‘of Tibur’ and its namesake is also the origin of Tivoli, a district near Rome. Modern travertine is formed from geothermally heated supersaturated alkaline waters, with raised pCO2, on emergence, waters degas CO2 due to the lower atmospheric pCO2, resulting in an increase in pH. Since carbonate solubility decreases with increased pH, precipitation is induced, precipitation may be enhanced by factors leading to a reduction in pCO2, for example increased air-water interactions at waterfalls may be important, as may photosynthesis. Precipitation may also be enhanced by evaporation in some springs, both calcite and aragonite are found in hot spring travertines, aragonite is preferentially precipitated when temperatures are hot, while calcite dominates when temperatures are cooler. When pure and fine, travertine is white, but often it is brown to yellow due to impurities, travertine may precipitate out directly onto rock and other inert materials as in Pamukkale or Yellowstone for example. The latter has a historic value, because it was one of the quarries that Gian Lorenzo Bernini selected material from to build the famous Colonnade of St. Peters Square in Rome in 1656-1667. Michaelangelo also chose travertine as the material for the ribs of the dome of St Peters Basilica. Travertine derives its name from the town, known as Tibur in ancient Roman times. The ancient name for the stone was lapis tiburtinus, meaning tibur stone, detailed studies of the Tivoli and Guidonia travertine deposits revealed diurnal and annual rhythmic banding and laminae, which have potential use in geochronology. Cascades of natural lakes formed behind travertine dams can be seen in Pamukkale, Turkey, in Central Europes last post-glacial palaeoclimatic optimum, huge deposits of tufa formed from karst springs. On a smaller scale, these karst processes are still working, travertine has been an important building material since the Middle Ages. Travertine has formed sixteen huge, natural dams in a valley in Croatia known as Plitvice Lakes National Park, clinging to moss and rocks in the water, the travertine has built up over several millennia to form waterfalls up to 70 m in height. In the U. S. the most well-known place for travertine formation is Yellowstone National Park, Oklahoma has two parks dedicated to this natural wonder
8.
Limestone
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Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate, about 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, most cave systems are through limestone bedrock. The first geologist to distinguish limestone from dolomite was Belsazar Hacquet in 1778, like most other sedimentary rocks, most limestone is composed of grains. Most grains in limestone are skeletal fragments of organisms such as coral or foraminifera. Other carbonate grains comprising limestones are ooids, peloids, intraclasts and these organisms secrete shells made of aragonite or calcite, and leave these shells behind when they die. Limestone often contains variable amounts of silica in the form of chert or siliceous skeletal fragment, some limestones do not consist of grains at all, and are formed completely by the chemical precipitation of calcite or aragonite, i. e. travertine. Secondary calcite may be deposited by supersaturated meteoric waters and this produces speleothems, such as stalagmites and stalactites. Another form taken by calcite is oolitic limestone, which can be recognized by its granular appearance, the primary source of the calcite in limestone is most commonly marine organisms. Some of these organisms can construct mounds of rock known as reefs, below about 3,000 meters, water pressure and temperature conditions cause the dissolution of calcite to increase nonlinearly, so limestone typically does not form in deeper waters. Limestones may also form in lacustrine and evaporite depositional environments, calcite can be dissolved or precipitated by groundwater, depending on several factors, including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits a characteristic called retrograde solubility, in which it becomes less soluble in water as the temperature increases. Impurities will cause limestones to exhibit different colors, especially with weathered surfaces, Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Crystals of calcite, quartz, dolomite or barite may line small cavities in the rock, when conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together, or it can fill fractures. Travertine is a banded, compact variety of limestone formed along streams, particularly there are waterfalls. Calcium carbonate is deposited where evaporation of the leaves a solution supersaturated with the chemical constituents of calcite. Tufa, a porous or cellular variety of travertine, is found near waterfalls, coquina is a poorly consolidated limestone composed of pieces of coral or shells. During regional metamorphism that occurs during the building process, limestone recrystallizes into marble
9.
Cast stone
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Cast stone is a concrete masonry product simulating natural-cut stone and is used in architectural applications. Cast stone is used for features, trim, or ornament, facing buildings or other structures. Cast stone can be made from white and/or grey cements, manufactured or natural sands, crushed stone or natural gravels, Cast stone may replace natural-cut limestone, brownstone, sandstone, bluestone, granite, slate, coral rock, travertine, and other natural building stones. Cast stone has been a building material for hundreds of years. The earliest known use of cast stone dates about to the year 1138 at Carcassonne, France, Cast stone was first used extensively in London in the 19th century and gained widespread acceptance in America in 1920. Some researchers have speculated that the Egyptian pyramids were formed using a form of cast stone. It was cheaper and more uniform than natural stone, and widely used, in engineering projects, it had the advantage that transporting the bulk materials and casting them near the place of use was cheaper than transporting very large pieces of stone. According to Rupert Gunnis a Dutchman named Van Spangen set up an artificial stone manufactury at Bow in London in 1800. Having later gone into partnership with a Mr. Powell the firm was broken up in 1828 and his material was not the same as the ceramic body used by Mrs. Coade, but made from Portland cement, broken natural stone, pounded marble and coarse sand. Around 1840 Austin entered into partnership with John Seeley, Seeley had trained at the Royal Academy Schools and also made an artificial stone, which he called artificial limestone, before entering into partnership with Austin. In 1841 Austin and Seeley published their first catalogue, Collection of Ornaments at Austin & Seeleys Artificial Stone Works for Gardens, Parks, the firm continued in production until about 1872. When the blocks are set hard the moulds are loosened and the placed in a solution of silicate of soda for about two weeks for the purpose of indurating and hardening them. Many manufacturers turn out a material that is practically non-porous and is able effectually to resist the influence of sea air or the impure atmosphere of large towns. Today, cast stone is a Portland cement-based architectural precast concrete product manufactured using high quality fine, the use of a high percentage of fine aggregate creates a very smooth, consistent texture for the building elements being cast, resembling natural cut stone. Other ingredients such as chemical admixtures, pozzolans, and pigments also may be added, Cast stone frequently is produced with a low water-to-cement ratio mixture with a dry consistency. The mixture is consolidated into a mould using an air-driven, or electric, tamping device or vibration under pressure, products manufactured in this manner are referred to as vibrant-dry-tamped cast stone. Over the last decade, new types of admixtures have been developed for VDT concrete products and these new admixtures do not normally work with wet cast concrete. These new plasticizers are more efficient than using air-entraining agents to increase compaction in VDT concrete, some plasticizers have chemical properties that react with the cement to increase ultimate strengths of semi-dry concrete
10.
Concrete masonry unit
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A concrete masonry unit is a standard size rectangular block used in building construction. Those that use cinders are called cinder blocks in Canada, the United States, and New Zealand, breeze blocks in the United Kingdom and New Zealand, and hollow blocks in the Philippines. In Australia they are known as Besser blocks or besser bricks. Clinker blocks use clinker as aggregate, in non-technical usage, the terms cinder block and breeze block are often generalized to cover all of these varieties. Concrete blocks are made from cast concrete, lower density blocks may use industrial wastes, such as fly ash or bottom ash, as an aggregate. Lightweight blocks can also be produced using autoclaved aerated concrete, Concrete blocks may be produced with hollow centers to reduce weight or improve insulation. The use of blockwork allows structures to be built in the masonry style with layers of staggered blocks. In the US, the most common size is 16 in ×8 in ×8 in. In Ireland and the UK, blocks are usually 440 mm ×215 mm ×100 mm excluding mortar joints, in New Zealand and Canada, blocks are usually 390 mm ×190 mm ×190 mm excluding mortar joints. Block cores are typically tapered so that the top surface of the block has a surface on which to spread a mortar bed. Most CMUs have two cores, but three- and four-core units are also produced, a core also allows for the insertion of steel reinforcement, tying individual blocks together in the assembly, with the goal of greatly increased strength. To hold the reinforcement in proper position and to bond the block to the reinforcement, reinforcement is primarily used to impart greater tensile strength to the assembly, improving its ability to resist lateral forces such as wind load and seismic forces. A variety of specialized shapes exist to allow special construction features, u-shaped blocks or knockout blocks with notches to allow the construction of bond beams or lintel assemblies, using horizontal reinforcing grouted into place in the cavity. Blocks with a channel on the end, known as jamb blocks, blocks with grooved ends permit the construction of control joints, allowing a filler material to be anchored between the un-mortared block ends. Other features, such as radiused corners known as bullnoses may be incorporated, a wide variety of decorative profiles also exist. Concrete masonry units may be formulated with special aggregates to produce specific colors or textures for finish use, special textures may be produced by splitting a ribbed or solid two-block unit, such factory-produced units are called split-rib or split-face blocks. Blocks may be scored by grooves the width of a joint to simulate different block modules. For example, an 8-by-16-inch block may be scored in the middle to simulate 8-by-8-inch masonry, with the grooves filled with mortar, American suburban houses typically employ a concrete foundation vibrant and slab with a concrete block wall on the perimeter
11.
Glass
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Glass is a non-crystalline amorphous solid that is often transparent and has widespread practical, technological, and decorative usage in, for example, window panes, tableware, and optoelectronics. The most familiar, and historically the oldest, types of glass are silicate glasses based on the chemical compound silica, the primary constituent of sand. The term glass, in usage, is often used to refer only to this type of material. Many applications of silicate glasses derive from their optical transparency, giving rise to their use as window panes. Glass can be coloured by adding metallic salts, and can also be painted and printed with vitreous enamels and these qualities have led to the extensive use of glass in the manufacture of art objects and in particular, stained glass windows. Although brittle, silicate glass is extremely durable, and many examples of glass fragments exist from early glass-making cultures, because glass can be formed or moulded into any shape, it has been traditionally used for vessels, bowls, vases, bottles, jars and drinking glasses. In its most solid forms it has also used for paperweights, marbles. Some objects historically were so commonly made of glass that they are simply called by the name of the material, such as drinking glasses. Porcelains and many polymer thermoplastics familiar from everyday use are glasses and these sorts of glasses can be made of quite different kinds of materials than silica, metallic alloys, ionic melts, aqueous solutions, molecular liquids, and polymers. For many applications, like glass bottles or eyewear, polymer glasses are a lighter alternative than traditional glass, silica is a common fundamental constituent of glass. In nature, vitrification of quartz occurs when lightning strikes sand, forming hollow, fused quartz is a glass made from chemically-pure SiO2. It has excellent resistance to shock, being able to survive immersion in water while red hot. However, its high melting-temperature and viscosity make it difficult to work with, normally, other substances are added to simplify processing. One is sodium carbonate, which lowers the transition temperature. The soda makes the glass water-soluble, which is undesirable, so lime, some magnesium oxide. The resulting glass contains about 70 to 74% silica by weight and is called a soda-lime glass, soda-lime glasses account for about 90% of manufactured glass. Most common glass contains other ingredients to change its properties, lead glass or flint glass is more brilliant because the increased refractive index causes noticeably more specular reflection and increased optical dispersion. Adding barium also increases the refractive index, iron can be incorporated into glass to absorb infrared energy, for example in heat absorbing filters for movie projectors, while cerium oxide can be used for glass that absorbs UV wavelengths
12.
Adobe
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Adobe is a building material made from earth and often organic material. Adobe is among the earliest building materials, and is used throughout the world, modern methods of construction allow the pouring of whole adobe walls that are reinforced with steel. In dry climates, adobe structures are extremely durable, and account for some of the oldest existing buildings in the world. Adobe buildings offer significant advantages due to their greater thermal mass, cases where adobe structures were widely damaged during earthquakes include the 1976 Guatemala earthquake, the 2003 Bam earthquake and the 2010 Chile earthquake. Puebloan peoples built their structures with handfuls or basketfuls of adobe. Adobe bricks were used in Spain from the Late Bronze and Iron Ages and its wide use can be attributed to its simplicity of design and manufacture, and economics. A distinction is made between the smaller adobes, which are about the size of ordinary baked bricks, and the larger adobines. The word adobe /əˈdoʊbiː/ has existed for around 4000 years with little change in either pronunciation or meaning. The word can be traced from the Middle Egyptian word ɟbt mudbrick, Middle Egyptian evolved into Late Egyptian, Demotic or pre-Coptic, and finally to Coptic, where it appeared as τωωβε tōʾpə. This was borrowed into Arabic as الطوب aṭ-ṭawbu or aṭ-ṭūbu, with the definite article al- attached, tuba, English borrowed the word from Spanish in the early 18th century. In more modern English usage, the adobe has come to include a style of architecture popular in the desert climates of North America. An adobe brick is a material made of earth mixed with water. The soil composition typically contains sand, silt and clay, straw is useful in binding the brick together and allowing the brick to dry evenly, thereby preventing cracking due to uneven shrinkage rates through the brick. The most desirable soil texture for producing the mud of adobe is 15% clay, 10–30% silt, another source quotes 15–25% clay and the remainder sand and coarser particles up to cobbles 50 to 250 mm with no deleterious effect. Modern adobe is stabilized with either emulsified asphalt or Portland cement up to 10% by weight, no more than half the clay content should be expansive clays with the remainder non-expansive illite or kaolinite. Too much expansive clay results in uneven drying through the resulting in cracking. Typically the soils of the Southwest United States, where construction is in use, are an adequate composition. Adobe walls are bearing, i. e. they carry their own weight into the foundation rather than by another structure
13.
Bricklayer
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A bricklayer, which is related to but different from a mason, is a craftsman who lays bricks to construct brickwork. The terms also refer to personnel who use blocks to construct blockwork walls, in British and Australian English, a bricklayer is colloquially known as a brickie. A stone mason is a term applied to one who lays any combination of stones, cinder blocks, bricklaying may also enjoyed as a hobby. For example, Winston Churchill did bricklaying as a hobby, bricklaying and masonry is an ancient profession that even centuries later requires modern training. While some online sites say they can get you certified in a little as 30 days, most bricklayers today attend vocational or technical schools and receive in-depth and it is likely that as long as man seeks shelter from the elements, there will be work for these skilled professionals. While steel and glass make up the skyscraper, it is hard to imagine a world where the work of a mason is not held in high demand. Picture of an Ehrbarkeit Traditional belt-buckle of a bricklayer, fante also spent a significant portion of his youth apprenticed to his father. In Aleksandr Solzhenitsyns One Day in the Life of Ivan Denisovich, the title character, the long-running British childrens TV series Look and Read featured Bill the Brickie, who would build words with bricks to demonstrate the use of morphemes, such as -ed or -ing. Brick hod Construction Construction worker Guild Stonemasonry
14.
Rebar
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Rebars surface is often patterned to form a better bond with the concrete. Rebar has been used in construction since at least the 15th century, more recently, during the 18th century, rebar was used to form the carcass of the Leaning Tower of Nevyansk in Russia, built on the orders of the industrialist Akinfiy Demidov. The cast iron used for the rebar was of high quality, the carcass of the tower was connected to its cast iron tented roof, crowned with one of the first known lightning rods. More recently these techniques have been refined by embedding the steel bars in the concrete, concrete is a material that is very strong in compression, but relatively weak in tension. To compensate for this imbalance in concretes behavior, rebar is cast into it to carry the tensile loads, rebar is also employed to confer resistance to concentrated loads by providing enough localized resistance and stiffness for a load to spread through a wider area. Rebar may also be used to other steel bars in the correct position to accommodate their loads. External steel tie bars can constrain and reinforce masonry structures, as illustrated by the Nevyansk Tower or ancient structures in Rome, masonry structures and the mortar holding them together have similar properties to concrete and also have a limited ability to carry tensile loads. Some standard masonry units like blocks and bricks are made with voids to accommodate rebar and this combination is known as reinforced masonry. Steel has a thermal expansion coefficient nearly equal to that of modern concrete, if this were not so, it would cause problems through additional longitudinal and perpendicular stresses at temperatures different from the temperature of the setting. To prevent such a failure, rebar is either deeply embedded into adjacent structural members, or bent and hooked at the ends to lock it around the concrete and other rebar. This first approach increases the friction locking the bar into place, common rebar is made of unfinished tempered steel, making it susceptible to rusting. Normally the concrete cover is able to provide a pH value higher than 12 avoiding the corrosion reaction, too little concrete cover can compromise this guard through carbonation from the surface, and salt penetration. Too much concrete cover can cause bigger crack widths which also compromises the local guard and this phenomenon is known as oxide jacking. This is a problem where the concrete is exposed to salt water, as in bridges where salt is applied to roadways in winter. Even damaged bars have shown better performance than uncoated reinforcing bars, though issues from debonding of the coating from the bars. These bars are used in over 70,000 bridge decks in the USA, fiber-reinforced polymer rebar is also used in high-corrosion environments. It is available in forms, such as spirals for reinforcing columns, common rods. Most commercially available rebar is made from glass fibre reinforced thermoset resins
15.
Framing (construction)
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Framing, in construction, is the fitting together of pieces to give a structure support and shape. Framing materials are wood, engineered wood, or structural steel. Light-frame construction using standardized dimensional lumber has become the dominant construction method in North America, use of minimal structural material allows builders to enclose a large area with minimal cost, while achieving a wide variety of architectural styles. Historically mankind fitted naturally shaped wooden poles together as framework and then began using joints to connect the timbers, the studs in a balloon frame extend two stories from sill to plate. Platform framing superseded balloon framing and is the wooden framing method today. The name comes from each level being framed as a separate unit or platform. Modern light-frame structures usually gain strength from rigid panels but until recently carpenters employed various forms of diagonal bracing to stabilize walls. Diagonal bracing remains a vital part of many roof systems. Special framed shear walls are becoming common to help buildings meet the requirements of earthquake engineering. The alternative to framed construction is called mass wall construction which is made from horizontal layers of stacked materials such as log building, masonry, rammed earth, adobe. Wall framing in house construction includes the vertical and horizontal members of exterior walls and interior partitions, the platforms may be the boxed structure of a ceiling and roof, or the ceiling and floor joists of the story above. The platform also provides the support against wind and holds the stick walls true. Any lower platform supports the weight of the platforms and walls above the level of its component headers, framing lumber should be grade-stamped, and have a moisture content not exceeding 19%. There are three common methods of framing a house. Post and beam, which is now used predominantly in barn construction, balloon framing using a technique suspending floors from the walls was common until the late 1940s, but since that time, platform framing has become the predominant form of house construction. Platform framing often forms wall sections horizontally on the prior to erection, easing positioning of studs. The top and bottom plates are end-nailed to each stud with two nails at least 3.25 in in length, studs are at least doubled at openings, the jack stud being cut to receive the lintels that are placed and end-nailed through the outer studs. Others, such as rigid glass-fiber, asphalt-coated fiberboard, polystyrene or polyurethane board, in this latter case, the wall should be reinforced with a diagonal wood or metal bracing inset into the studs
16.
Tar paper
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Tar paper is a heavy-duty paper used in construction. Tar paper is made by impregnating paper or fiberglass mat with tar, tar paper is distinguished from roofing felt which is impregnated with asphalt instead of tar, but these two products are used the same way, and sometimes are informally used as synonyms. Tar paper has been in use for centuries, originally felt was made from recycled rags but today felts are made of recycled paper products and sawdust. The most common product is the so-called #15 felt, before the oil crisis felt weighed about 15 pounds per square and hence the asphalt-impregnated felt was called 15# or 15 pound felt. Modern, inorganic mats no longer weigh 0.73 kg/m2, in fact, #15 mats can weigh from 7.5 to 12.5 pounds/sq depending on the manufacturer and the standard to which felt is made. Thirty pound felt, of 30# felt, is now #30 felt, tar paper is more accurately a Grade D building paper which is widely used in the west. Building paper is manufactured from virgin kraft paper, unlike felts, the longer fibres in the kraft paper allow for a lighter weight product with similar and often better mechanical properties than felt. Grade papers are rated in minutes—the amount of time it takes for a sensitive chemical indicator to change colour when a small boat-like sample is floated on water. Common grades include 10,20,30, and 60 minute, the higher the rating the more moisture resistant and the heavier. A typical 20 minute paper will weigh about 3.3 lbs per square, a 30-minute paper 3.75, the smaller volume of material however does tend to make these papers less resistant to moisture than heavier felts. Tar paper is far less common than asphalt felt paper and is used, among other things, for waterproofing roofs to prevent ingress of moisture. It is used in a percentage of built-up roofs, as underlayment with asphalt, wood, shake. It can be installed in several ways, such as staples or roofing nails, but it is also sometimes applied in several layers with hot asphalt, cold asphalt, or non-asphaltic adhesives
17.
Weep
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A weep, a weep hole, or a weep-brick is a small opening that allows water to drain from within an assembly. Weeps are located at the bottom of the object to allow for drainage, weeps may also be necessary in a retaining wall, so water can escape from the retained earth, thus lessening the hydrostatic load on the wall and preventing moisture damage from freeze/thaw cycles. In such cases the weeps consist of plastic, clay or metal pipes extending through the wall to a layer of porous backfill. Typically, weeps are arranged to direct water which may have entered an assembly from outside back to the outside, weeps may also be found in metal windows and glazed curtain walls to permit interstitial condensation to escape. In building construction, weeps are typically found in a masonry veneer or cavity wall, the cavity serves as a way to drain this water back out through the weep holes. The weep holes allow wind to create an air stream through the cavity, the stream removes evaporated water from the cavity to the outside. Weep holes are placed above windows to prevent dry rot of a wooden window frame. The open head joint process is done by leaving out mortar from the joints and this create open holes of the same size of the typical spacing of the joints. This is the most common method and most effective way to water from the cavity. The spacing between open head joints can be done at every 24 inches, one of the problems with this method is that the open head joints create large holes which may not be appealing. Some maintenance workers may also inadvertently patch those holes up without realizing they are weep holes, there are some products such as aluminum vent and plastic grid that can be inserted into the weep holes to make them less conspicuous. Cotton wicks can be used to form weeps, a rope of up to 12 inches in length is placed in the joints. The other end of the rope is extended up into the cavity wall, the process of evaporation is slower than with weep holes. Also, the cotton could catch fire, another type of weeps is a tube that can be made formed by using hollow plastic or metal. The spacing between the tubes is about 16 inches apart, the installation of the tubes are done at angle to allow water to drip out. If the angle is too steep, the hole inside the wall cavity will be too high for water to come out. If the angle is too flat, the used in laying the bricks may drop into cavity. Sometime a shallow layer of gravel is laid to prevent mortar dropping from blocking the tubes, the thickness of the plastic tube, however small, will create a small dam that allows water to pool inside the wall cavity
18.
Thermal insulation
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Thermal insulation is the reduction of heat transfer between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes, heat flow is an inevitable consequence of contact between objects of differing temperature. Thermal insulation provides a region of insulation in which thermal conduction is reduced or thermal radiation is reflected rather than absorbed by the lower-temperature body, the insulating capability of a material is measured with thermal conductivity. Low thermal conductivity is equivalent to high insulating capability, in thermal engineering, other important properties of insulating materials are product density and specific heat capacity. Solid materials chosen for insulation have a low thermal conductivity k, as the thickness of insulation is increased, the thermal resistance also increases. For insulated cylinders, a critical radius must be reached, before the critical radius is reached any added insulation increases heat transfer. If the outside radius of a cylinder is increased by applying insulation, however, at the same time, the convective resistance is reduced. This implies that adding insulation below a critical radius actually increases the heat transfer. If the radius of the cylinder is smaller than the critical radius for insulation. Gases possess poor thermal conduction properties compared to liquids and solids, in order to further augment the effectiveness of a gas it may be disrupted into small cells which cannot effectively transfer heat by natural convection. Convection involves a larger flow of gas driven by buoyancy and temperature differences. In order to accomplish gas cell formation in man-made thermal insulation, glass and this principle is used industrially in building and piping insulation such as, cellulose, rock wool, polystyrene foam, urethane foam, vermiculite, perlite, and cork. Trapping air is also the principle in all highly insulating clothing materials such as wool, down feathers, the air-trapping property is also the insulation principle employed by homeothermic animals to stay warm, for example down feathers, and insulating hair such as natural sheeps wool. In both cases the primary insulating material is air, and the used for trapping the air is natural keratin protein. Maintaining acceptable temperatures in buildings uses a proportion of global energy consumption. For a period of time, Asbestos was also used, however, when well insulated, a building, is energy-efficient, thus saving the owner money. Provides more uniform throughout the space. Unlike heating and cooling equipment, insulation is permanent and does not require maintenance, upkeep, lowers the carbon footprint of a building
19.
Glass wool
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Glass wool is an insulating material made from fibres of glass arranged using a binder into a texture similar to wool. The process traps many small pockets of air between the glass, and these air pockets result in high thermal insulation properties. Glass wool is produced in rolls or in slabs, with different thermal and mechanical properties and it may also be produced as a material that can be sprayed or applied in place, on the surface to be insulated. The modern method for producing glass wool is the invention of Games Slayter working at the Owens-Illinois Glass Co and he first applied for a patent for a new process to make glass wool in 1933. Gases possess good thermal conduction properties compared to liquids and solids, in order to further augment the effectiveness of a gas it may be disrupted into small cells which cannot effectively transfer heat by natural convection. Convection involves a larger flow of gas driven by buoyancy and temperature differences. In order to accomplish formation of gas cells in man-made thermal insulation, glass. The same principle used in glass wool is used in other man-made insulators such as wool, styrofoam, wet suit neoprene foam fabrics. The air-trapping property is also the principle used in nature in down feathers. Natural sand and recycled glass are mixed and heated to 1,450 °C, the fiberglass is usually produced by a method similar to making cotton candy, by forcing it through a fine mesh by centripetal force, cooling on contact with the air. Cohesion and mechanical strength are obtained by the presence of a binder that “cements” the fibers together, a drop of bonder is placed at each fiber intersection. The fiber mat is then heated to around 200 °C to polymerize the resin and is calendered to give it strength, finally, the wool mat is cut and packed in rolls or panels, palletized, and stored for use. It is also used to insulate piping and for soundproofing, batts are precut, whereas blankets are available in continuous rolls. Compressing the material reduces its effectiveness, cutting it to accommodate electrical boxes and other obstructions allows air a free path to cross through the wall cavity. One can install batts in two layers across an unfinished attic floor, perpendicular to other, for increased effectiveness at preventing heat bridging. Blankets can cover joists and studs as well as the space between them, batts can be challenging and unpleasant to hang under floors between joists, straps, or staple cloth or wire mesh across joists, can hold it up. Gaps between batts can become sites of air infiltration or condensation and requires strict attention during the installation, by the same token careful weatherization and installation of vapour barriers is required to ensure that the batts perform optimally. Air infiltration can be reduced by adding a layer of cellulose loose-fill on top of the material
20.
Plaster
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Plaster is a building material used for the protective and/or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English plaster usually means a material used for the interiors of buildings, another imprecise term used for the material is stucco, which is also often used for plasterwork that is worked in some way to produce relief decoration, rather than flat surfaces. The most common types of plaster mainly contain either gypsum, lime, or cement, the plaster is manufactured as a dry powder and is mixed with water to form a stiff but workable paste immediately before it is applied to the surface. The reaction with water liberates heat through crystallization and the hydrated plaster then hardens, plaster can be relatively easily worked with metal tools or even sandpaper, and can be moulded, either on site or to make pre-formed sections in advance, which are put in place with adhesive. Plaster is not a material, it is suitable for finishing, rather than load-bearing. Forms of plaster have several other uses, in medicine plaster orthopedic casts are still often used for supporting set broken bones. In dentistry plaster is used to make dental models, various types of models and moulds are made with plaster. In art, lime plaster is the matrix for fresco painting. Gypsum plaster, or plaster of Paris, is produced by heating gypsum to about 300 °F, when the dry plaster powder is mixed with water, it re-forms into gypsum. The setting of unmodified plaster starts about 10 minutes after mixing and is complete in about 45 minutes, if plaster or gypsum is heated above 266 °F, hemihydrate is formed, which will also re-form as gypsum if mixed with water. On heating to 180 °C, the nearly water-free form, called γ-anhydrite is produced, γ-Anhydrite reacts slowly with water to return to the dihydrate state, a property exploited in some commercial desiccants. On heating above 250 °C, the anhydrous form called β-anhydrite or dead burned plaster is formed. A large gypsum deposit at Montmartre in Paris led calcined gypsum to be known as plaster of Paris. Plasterers often use gypsum to simulate the appearance of surfaces of wood, stone, or metal, on movie, nowadays, theatrical plasterers often use expanded polystyrene, although the job title remains unchanged. Plaster of Paris can be used to impregnate gauze bandages to make a material called plaster bandages. It is used similarly to clay, as it is shaped when wet, yet sets into a resilient. This is the material that was used to make classic plaster orthopedic casts to protect limbs with broken bones, set Modroc is an early example of a composite material. The hydration of plaster of Paris relies on the reaction of water with the dehydrated or partially hydrated calcium sulfate present in the plaster, lime plaster is a mixture of calcium hydroxide and sand
21.
Drywall
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Drywall is a panel made of calcium sulfate dihydrate with or without additives and normally pressed between a facer and a backer. It is used to make walls and ceilings. The plaster is mixed with fibre, plasticizer, foaming agent, and various additives that can decrease mildew, increase fire resistance, drywall construction became prevalent in North America as a speedier alternative to traditional lath and plaster. The first plasterboard plant in the UK was opened in 1888 in Rochester, Sackett Board was invented in 1894 by Augustine Sackett and Fred Kane. It was made by layering plaster within four plies of wool felt paper, sheets were 36 ×36 × 1/4 thick with open edges. Gypsum board evolved between 1910 and 1930 beginning with wrapped board edges and elimination of the two layers of felt paper in favor of paper-based facings. In 1910 United States Gypsum Corporation bought Sackett Plaster Board Company, providing efficiency of installation, it was developed additionally as a measure of fire resistance. Later air entrainment technology made boards lighter and less brittle, then joint treatment materials, rock lath was an early substrate for plaster. As it evolved, it was faced with paper impregnated with gypsum crystals that bonded with the applied facing layer of plaster, a wallboard panel consists of a layer of gypsum plaster sandwiched between two layers of paper. The raw gypsum, CaSO4·2 H2O, is heated to drive off the water then slightly rehydrated to produce the hemihydrate of calcium sulfate, the board is then formed by sandwiching a core of the wet mixture between two sheets of heavy paper or fibreglass mats. When the core sets it is dried in a large drying chamber. Drying chambers typically use natural gas today, to dry 1 MSF of wallboard, between 1,750,000 and 2,490,000 BTU is required. Organic dispersants/plasticisers are used so the slurry will flow during manufacture, coal-fired power stations include devices called scrubbers to remove sulphur from their exhaust emissions. The sulphur is absorbed by powdered limestone in a process called flue-gas desulphurization and this is commonly used in drywall construction in the United States and elsewhere. Drywall panels in the United States are manufactured in 48-inch, 54-inch and 96-inch wide panels in varying lengths to suit the application, lengths up to 12-feet are commonly available, though the most common length is 8-feet. Common panel thicknesses are 1⁄2-inch and 5⁄8-inch, with panels also available in 1⁄4-inch, 3⁄8-inch, 3/4-inch and 1-inch for specific applications, in Europe plasterboard is manufactured in metric sizes, with the common sizes being corollaries of old imperial sizes. Most plasterboard is made in 120 cm-wide sheets, though 90 cm and 60 cm wide sheets are also made,120 cm wide plasterboard is most commonly made in 240 cm lengths, though 250,260,270,280,300 cm and even longer are commonly available. Thicknesses of plasterboard available are 9.5 mm to 25 mm, however four side chamfered drywall is not currently offered by major UK manufacturers for general use
22.
Dry stone
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Dry stone is a building method by which structures are constructed from stones without any mortar to bind them together. Dry stone structures are stable because of their construction method. Dry stone technology is best known in the context of wall construction, but dry stone artwork, buildings, bridges, Dry stone walls have been traditionally used in building construction as field boundaries and garden or churchyard walls, and on steep slopes as retaining walls for terracing. Some dry-stone wall constructions in north-west Europe have been dated back to the Neolithic Age, some Cornish hedges are believed by the Guild of Cornish Hedgers to date from 5000 BC, although there appears to be little dating evidence. In County Mayo, Ireland, a field system made from dry-stone walls. The cyclopean walls of the acropolis of Mycenae have been dated to 1350 BC, in Belize, the Mayan ruins at Lubaantun illustrate use of dry stone construction in architecture of the 8th and 9th centuries AD. When used as boundaries, dry stone structures often are known as dykes. Dry stone walls are characteristic of areas of Britain and Ireland where rock outcrops naturally or large stones exist in quantity in the soil. They are especially abundant in the West of Ireland, particularly Connemara and they may also be found throughout the Mediterranean, including retaining walls used for terracing. Such constructions are common where large stones are plentiful or conditions are too harsh for hedges capable of retaining livestock to be grown as field boundaries. Many thousands of miles of such walls exist, most of them centuries old, the technique of construction was brought to America primarily by English and Scots-Irish immigrants. The technique was taken to Australia and New Zealand. Similar walls also are found in the Swiss-Italian border region, where they are used to enclose the open space under large natural boulders or outcrops. The higher-lying rock-rich fields and pastures in Bohemias South-Western border range of Šumava are often lined by dry stone walls built of field-stones removed from the arable or cultural land and they serve both as cattle/sheep fences and the lots borders. Sometimes also the dry stone terracing is apparent, often combined with parts of masonry that are held together by a clay-cum-needles composite mortar. Great Zimbabwe is a city in the south-eastern hills of Zimbabwe, near Lake Mutirikwe. It was the capital of the Kingdom of Zimbabwe during the countrys Late Iron Age, construction on the monument began in the 11th century and continued until the 15th century. The exact identity of the Great Zimbabwe builders is at present unknown, the stone city spans an area of 722 hectares which, at its peak, could have housed up to 18,000 people
23.
Friction
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Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction, Dry friction resists relative lateral motion of two surfaces in contact. Dry friction is subdivided into static friction between non-moving surfaces, and kinetic friction between moving surfaces, fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces, skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body. Internal friction is the force resisting motion between the making up a solid material while it undergoes deformation. When surfaces in contact move relative to other, the friction between the two surfaces converts kinetic energy into thermal energy. This property can have consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire. Kinetic energy is converted to thermal energy whenever motion with friction occurs, another important consequence of many types of friction can be wear, which may lead to performance degradation and/or damage to components. Friction is a component of the science of tribology, Friction is not itself a fundamental force. Dry friction arises from a combination of adhesion, surface roughness, surface deformation. The complexity of interactions makes the calculation of friction from first principles impractical and necessitates the use of empirical methods for analysis. Friction is a non-conservative force - work done against friction is path dependent, in the presence of friction, some energy is always lost in the form of heat. Thus mechanical energy is not conserved, the Greeks, including Aristotle, Vitruvius, and Pliny the Elder, were interested in the cause and mitigation of friction. They were aware of differences between static and kinetic friction with Themistius stating in 350 A. D. that it is easier to further the motion of a moving body than to move a body at rest. The classic laws of sliding friction were discovered by Leonardo da Vinci in 1493, a pioneer in tribology and these laws were rediscovered by Guillaume Amontons in 1699. Amontons presented the nature of friction in terms of surface irregularities, the understanding of friction was further developed by Charles-Augustin de Coulomb. Coulomb further considered the influence of sliding velocity, temperature and humidity, the distinction between static and dynamic friction is made in Coulombs friction law, although this distinction was already drawn by Johann Andreas von Segner in 1758. Leslie was equally skeptical about the role of adhesion proposed by Desaguliers, in Leslies view, friction should be seen as a time-dependent process of flattening, pressing down asperities, which creates new obstacles in what were cavities before
