Mortise and tenon
The mortise and tenon joint has been used for thousands of years by woodworkers around the world to join pieces of wood, mainly when the adjoining pieces connect at an angle of 90°. In its basic form it is simple and strong. Although there are many joint variations, the mortise and tenon comprises two components, the mortise hole and the tenon tongue. The tenon, formed on the end of a member generally referred to as a rail, is inserted into a square or rectangular hole cut into the corresponding member. The tenon is cut to fit the hole exactly and usually has shoulders that seat when the joint fully enters the mortise hole. The joint may be glued, pinned, or wedged to lock it in place and this joint is used with other materials. For example, it is a method for stonemasons and blacksmiths. A mortise is a cavity cut into a timber to receive a tenon, there are several kinds of mortise, Open mortise a mortise that has only three sides. Stub mortise a mortise, the depth of which depends on the size of the timber.
Through mortise a mortise that passes entirely through a piece, wedged half-dovetail a mortise in which the back is wider, or taller, than the front, or opening. The space for the wedge initially allows room for the tenon to be inserted and it is sometimes called a suicide joint, since it is a one-way trip. Through-wedged half-dovetail a wedged half-dovetail mortise that passes entirely through the piece, a tenon is a projection on the end of a timber for insertion into a mortise. Usually the tenon is taller than it is wide. There are several kinds of tenon, Stub tenon short, the depth of which depends on the size of the timber, through tenon a tenon that passes entirely through the piece of wood it is inserted into, being clearly visible on the back side. Loose tenon a tenon that is a part of the joint. Teasel tenon a term used for the tenon on top of a jowled or gunstock post, a common element of the English tying joint. Top tenon the tenon that occurs on top of a post, hammer-headed tenon a method of forming a tenon joint when the shoulders cannot be tightened with a clamp.
Half shoulder tenon An asymmetric tenon with a shoulder on one side only, a common use is in framed and braced doors
An ember is a glowing, hot coal made of greatly heated wood, coal, or other carbon-based material that remain after, or sometimes precede, a fire. Embers can glow very hot, sometimes as hot as the fire which created them, in order to avoid the danger of accidentally spreading a fire, many campers pour water on the embers or cover them in dirt. They are often used for cooking, such as in charcoal barbecues and this is because embers radiate a more constant form of heat, as opposed to an open fire which is constantly changing along with the heat it radiates. An ember is formed when a fire has only partially burnt a piece of fuel. Often this happens because the chemical energy is so deep into the center that air does not reach it. It continues to stay hot and does not lose its thermal energy quickly because combustion is still happening at a low level, the small yellow and red lights often seen among the embers are actually combustion. There just is not enough combustion happening at one time to create a flame, once the embers are completely burned through, they are not carbon as is commonly believed, but rather various other oxidized minerals like calcium and phosphorus.
At that point they are called ashes. See, Wood ash for more on the residue that is left, embers play a large role in forest fires. Since embers are typically burnt leaves and thus small and lightweight, during a large fire, with the right wind conditions, embers can be blown far ahead of the fire front, starting spot fires several kilometres away. A number of measures can be undertaken by homeowners to reduce the consequences of such an ember attack that bombards especially wooden structures
In its broadest sense mortar includes pitch 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, 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 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 Greek colony of Dicaearchia near Naples, the Romans 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, 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
The finest linoleum floors, known as inlaid, are extremely durable, they were made by joining and inlaying solid pieces of linoleum. Cheaper patterned linoleum came in different grades or gauges, and were printed with thinner layers which were prone to wear and tear. High quality linoleum is flexible and thus can be used in buildings where a more material would crack. Linoleum was invented by Englishman Frederick Walton, in 1855, Walton happened to notice the rubbery, flexible skin of solidified linseed oil that had formed on a can of oil-based paint, and thought that it might form a substitute for India rubber. Raw linseed oil oxidizes very slowly, Walton accelerated the process by heating it with lead acetate and this made the oil form a resinous mass into which lengths of cheap cotton cloth were dipped until a thick coating formed. The coating was scraped off and boiled with benzene or similar solvents to form a varnish, Walton initially planned to sell his varnish to the makers of water-repellent fabrics such as oilcloth, and patented the process in 1860.
However, his method had problems, the cotton cloth soon fell apart, little interest was shown in his varnish. In addition, his first factory burned down, and he had persistent, such surfaces being afterward printed, embossed, or otherwise ornamented. Waltons friend Jerimiah Clarke designed the linoleum patterns, typically with a Grecian urn decor around the borders, unlike Waltons process, which took weeks, Parnacott’s method took only a day or two, although the quality of the linoxyn was not as good. Despite this, many opted to use the less expensive Parnacott process. Corticine was mainly made of cork dust and linoxyn without a cloth backing, by 1869 Walton’s factory in Staines, England was exporting to Europe and the United States. Walton opened the American Linoleum Manufacturing Company in 1872 on Staten Island, in partnership with Joseph Wild, the company’s town being named Linoleumville. It was the first U. S. linoleum manufacturer, but was followed by the American Nairn Linoleum Company, established by Sir Michael Nairn in 1887, in Kearny.
Congoleum now manufactures sheet vinyl and no longer has a linoleum line, Walton was unhappy with Michael Nairn & Co’s use of the name Linoleum and brought a lawsuit against them for trademark infringement. It is considered to be the first product name to become a generic term, in the late nineteenth and early twentieth centuries, it was favoured in hallways and passages, and as a surround for carpet squares. However, most people associate linoleum with its common twentieth century use on kitchen floors and its water resistance enabled easy maintenance of sanitary conditions and its resilience made standing easier and reduced breakage of dropped china. Other products devised by Walton included Linoleum Muralis in 1877, which better known as Lincrusta. Essentially a highly durable linoleum wallcovering, Lincrusta could be manufactured to resemble carved plaster or wood and it was very successful, and inspired a much cheaper imitation, originally devised by one of Walton’s showroom managers
The handle and blade of some types of chisel are made of metal or of wood with a sharp edge in it. Chiselling use involves forcing the blade into some material to cut it, the driving force may be applied by pushing by hand, or by using a mallet or hammer. In industrial use, a ram or falling weight drives a chisel into the material. A gouge, one type of chisel, serves - particularly in woodworking, gouges most frequently produce concave surfaces. A gouge typically has a U-shaped cross-section, chisel comes from the Old French cisel, modern ciseau, Late Latin cisellum, a cutting tool, from caedere, to cut. Chisels have a variety of uses. Many types of chisel have been devised, each suited to its intended use. Different types of chisel may be constructed differently, in terms of blade width or length, as well as shape. They may have a wooden or plastic handle attached using a tang or socket, woodworking chisels range from small hand tools for tiny details, to large chisels used to remove big sections of wood, in roughing out the shape of a pattern or design.
Typically, in woodcarving, one starts with a larger tool, one of the largest types of chisel is the slick, used in timber frame construction and wooden shipbuilding. There are many types of woodworking chisels used for specific purposes, such as, Butt chisel, short chisel with beveled sides and straight edge for creating joints. Carving chisels, used for designs and sculpting, cutting edges are many, such as gouge, parting, paring. Corner chisel, resembles a punch and has an L-shaped cutting edge, cleans out square holes and corners with 90 degree angles. Bevel edge chisel, can get into acute angles with its bevelled edges, flooring chisel and lifts flooring materials for removal and repair, ideal for tongue-and-groove flooring. Framing chisel, usually used with mallet, similar to a chisel, except it has a longer. Slick, a large chisel driven by pressure, never struck. Mortise chisel, rigid blade with cutting edge and deep, slightly tapered sides to make mortises. Paring chisel, has a long blade ideal for cleaning grooves, skew chisel, has a 60 degree cutting angle and is used for trimming and finishing
The phrase may refer to the finished product, from individual sculptures to hand-worked mouldings composing part of a tracery. It therefore forms an important hidden element in the art history of many cultures, outdoor wood sculptures do not last long in most parts of the world, so it is still unknown how the totem pole tradition developed. Many of the most important sculptures of China and Japan in particular are in wood, and so are the majority of African sculpture. Wood is light and can take very fine detail so it is suitable for masks. It is easier to work on than stone. Some of the finest extant examples of early European wood carving are from the Middle Ages in Germany, Russia and France, in England, many complete examples remain from the 16th and 17th century, where oak was the preferred medium. The gouge, a tool with a cutting edge used in a variety of forms and sizes for carving hollows, rounds. The coping saw, a saw that is used to cut off chunks of wood at once. The chisel and small, whose straight cutting edge is used for lines, the V-tool, used for parting, and in certain classes of flat work for emphasizing lines.
The U-Gauge, a deep gouge with a U-shaped cutting edge. Sharpening equipment, such as stones and a strop, necessary for maintaining edges. The nature of the wood being carved limits the scope of the carver in wood is not equally strong in all directions. The direction in which wood is strongest is called grain and it is smart to arrange the more delicate parts of a design along the grain instead of across it. Less commonly, this principle is used in solid pieces of wood. Probably the two most common used for carving in North America are basswood and tupelo, both are hardwoods that are relatively easy to work with. Chestnut, oak, American walnut and teak are very good woods, while for fine work Italian walnut, sycamore maple, pear, box or plum, are usually chosen. Decoration that is to be painted and of not too delicate a nature is often carved in pine, the type of wood is important. Hardwoods are more difficult to shape but have greater luster and longevity, softer woods may be easier to carve but are more prone to damage
A sledgehammer is a tool with a large, often metal head, attached to a lever. The size of its head allows a sledgehammer to apply more force than other hammers of similar size, along with the mallet, it shares the ability to distribute force over a wide area. This is in contrast to other types of hammers, which concentrate force in a small area. The word sledgehammer is derived from the Anglo Saxon slægan, which, in its first sense, the English words slag and slog are cognates. The handle can range from 50 centimetres to a full 1 metre long, depending on the mass of the head, the head mass is usually 1 to 3 kilograms. Modern heavy duty sledgehammers come with 10 to 20 pounds heads, sledgehammers usually require two hands and a swinging motion involving the entire torso, in contrast to smaller hammers used for driving in nails. The combination of a long swinging range, and heavy head, sledgehammers are often used in destruction work, for breaking through drywall or masonry walls. Sledgehammers are seldom used in mining operations, particularly hand steel.
Sledgehammers are used when substantial force is necessary to dislodge a trapped object, another common use is for driving fence posts into the ground. Sledgehammers are used by forces in raids on property to gain entry by force. They were and still are used by blacksmiths to shape heavy sections of iron. The British SAS counter terrorist team used sledgehammers to gain access to rooms during the 1980 Iranian Embassy Siege, today they use a tool called a dynamic hammer. Another iconic use of sledgehammers is for driving railroad spikes into wooden sleepers during rail construction, when the two ends of the Union Pacific railroad were joined at Promontory, Leland Stanford hammered a golden spike into a tie with a silver hammer. Sledges used to drive spikes for rails had curved heads that came down to a beak that was only one inch across. The shape meant that drivers needed to be accurate, and spot where the hit was often not much larger than a dime. Anything larger would hit the plate or the tie, the curved head kept the handle away from the rail, as the spikes were driven with the rail between the spike and the driver.
These are often called spike mauls, a drilling hammer, club hammer, lump hammer, crack hammer, mini-sledge or thor hammer is a small sledgehammer whose relatively light weight and short handle allow single-handed use. It is useful for demolition work, driving masonry nails
A jackhammer is a pneumatic or electro-mechanical tool that combines a hammer directly with a chisel. It was invented by William Mcreavy, who sold the patent to Charles Brady King. Hand-held jackhammers are generally powered by compressed air, but some are powered by electric motors. Larger jackhammers, such as rig mounted hammers used on machinery, are usually hydraulically powered. They are typically used to break up rock, pavement, a jackhammer operates by driving an internal hammer up and down. The hammer is first driven down to strike the back and back up to return the hammer to the position to repeat the cycle. The effectiveness of the jackhammer is dependent on how much force is applied to the tool and it is generally used like a hammer to break the hard surface or rock in construction works and it is not consider under earth moving equipment, along with its accessories. In British English, electromechanical versions are known as Kangos. Pneumatic drills were developed in response to the needs of mining, excavating, in 1838 Isaac Singer invented a steam driven drill.
A pneumatic drill was proposed by a C, the first percussion drill was made in 1848 and patented in 1849 by Jonathan J. Couch of Philadelphia, Pennsylvania. In this drill, the drill bit passed through the piston of a steam engine, the piston snagged the drill bit and hurled it against the rock face. In 1849, Couchs assistant, Joseph W. Fowle, filed a patent caveat for a drill of his own design. In Fowle’s drill, the bit was connected directly to the piston in the steam cylinder, specifically. The drill had a mechanism for turning the drill bit around its axis between strokes and for advancing the drill as the hole deepened, by 1850 or 1851, Fowle was using compressed air to drive his drill, making it the first true pneumatic drill. By contrast, compressed air could be conveyed over distances without loss of its energy. The need for a rock drill was obvious and this sparked research on pneumatic rock drills in Europe. A Frenchman, Cavé, and in 1851 patented, a drill that used compressed air. In 1854, in England, Thomas Bartlett made and patented a rock drill whose drill bit was connected directly to the piston of a steam engine, in 1855 Bartlett demonstrated his drill, powered by compressed air, to officials of the Mt.
Fréjus tunnel project
Stone sculpture is the result of forming 3-dimensional visually interesting objects from stone. It is an ancient activity where pieces of natural stone are shaped by the controlled removal of stone. Petroglyphs are perhaps the earliest form, images created by removing part of a surface which remains in situ, by incising, carving. Monumental sculpture covers large works, and architectural sculpture, which is attached to buildings. Hardstone carving is the carving for artistic purposes of semi-precious stones such as jade, onyx, rock crystal, sard or carnelian, alabaster or mineral gypsum is a soft mineral that is easy to carve for smaller works and still relatively durable. Engraved gems are small carved gems, including cameos, originally used as seal rings, carving stone into sculpture is an activity older than civilization itself, beginning perhaps with incised images on cave walls. Prehistoric sculptures were usually human forms, such as the Venus of Willendorf, cultures devised animal, human-animal and abstract forms in stone.
The earliest cultures used abrasive techniques, and modern technology employs pneumatic hammers, but for most of human history, sculptors used hammer and chisel as the basic tools for carving stone. In the direct method of carving, the work usually begins with the selection of a stone for carving. The artist using the method may use sketches but eschews the use of a physical model. The fully dimensional form or figure is created for the first time in the stone itself, as the artist removes material, sketches on the block of stone, and develops the work along the way. On the other hand, is the method, when the sculptor begins with a clearly defined model to be copied in stone. The models, usually made of plaster or modeling clay, may be fully the size of the intended sculpture, once the model is complete, a suitable stone must be found to fit the intended design. The model is copied in stone by measuring with calipers or a pointing machine. This method is used when the carving is done by other sculptors.
Some artists use the stone itself as inspiration, the Renaissance artist Michelangelo claimed that his job was to free the human form hidden inside the block. When he or she is ready to carve, the carver usually begins by knocking off, or pitching, large portions of unwanted stone. For this task he may select a point chisel, which is a long, hefty piece of steel with a point at one end, a pitching tool may be used at this early stage, which is a wedge-shaped chisel with a broad, flat edge
Metalworking is the process of working with metals to create individual parts, assemblies, or large-scale structures. The term covers a range of work from large ships and bridges to precise engine parts. It therefore includes a wide range of skills, processes. Metalworking is a science, hobby and trade and its historical roots span cultures and millennia. Metalworking has evolved from the discovery of smelting various ores, producing malleable and ductile metal useful for tools, modern metalworking processes, though diverse and specialized, can be categorized as forming, cutting, or joining processes. Todays machine shop includes a number of machine tools capable of creating a precise, the oldest archaeological evidence of copper mining and working was the discovery of a copper pendant in northern Iraq from 8,700 BCE. The earliest substantiated and dated evidence of metalworking in the Americas was the processing of copper in Wisconsin, Copper was hammered until brittle heated so it could be worked some more.
This technology is dated to about 4000-5000 BCE, the oldest gold artifacts in the world come from the Bulgarian Varna Necropolis and date from 4450 BCE. Not all metal required fire to obtain it or work it, isaac Asimov speculated that gold was the first metal. His reasoning is that by its chemistry it is found in nature as nuggets of pure gold, in other words, gold, as rare as it is, is sometimes found in nature as the metal that it is. There are a few metals that sometimes occur natively. Almost all other metals are found in ores, a mineral-bearing rock, another feature of gold is that it is workable as it is found, meaning that no technology beyond a stone hammer and anvil to work the metal is needed. This is a result of properties of malleability and ductility. The earliest tools were stone, bone and sinew, at some unknown point the connection between heat and the liberation of metals from rock became clear, rocks rich in copper and lead came into demand. These ores were mined wherever they were recognized, remnants of such ancient mines have been found all over Southwestern Asia.
Metalworking was being carried out by the South Asian inhabitants of Mehrgarh between 7000–3300 BCE, the end of the beginning of metalworking occurs sometime around 6000 BCE when copper smelting became common in Southwestern Asia. Ancient civilisations knew of seven metals. Here they are arranged in order of their potential, Iron +0.44 V
Wood is a porous and fibrous structural tissue found in the stems and roots of trees, and other woody plants. It is a material, a natural composite of cellulose fibers which are strong in tension embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, in a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It conveys water and nutrients between the leaves, other growing tissues, and the roots, Wood may refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber. In 2005, the stock of forests worldwide was about 434 billion cubic meters. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy, in 1991 approximately 3.5 billion cubic meters of wood were harvested. Dominant uses were for furniture and building construction, a 2011 discovery in the Canadian province of New Brunswick discovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago.
Wood can be dated by carbon dating and in species by dendrochronology to make inferences about when a wooden object was created. People have used wood for millennia for many purposes, primarily as a fuel or as a material for making houses, weapons, packaging, artworks. Constructions using wood date back ten thousand years, buildings like the European Neolithic long house were made primarily of wood. Recent use of wood has changed by the addition of steel. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the climate at that time. This process is known as growth, it is the result of cell division in the vascular cambium, a lateral meristem. These cells go on to form thickened secondary cell walls, composed mainly of cellulose, hemicellulose, if the distinctiveness between seasons is annual, these growth rings are referred to as annual rings. Where there is little seasonal difference growth rings are likely to be indistinct or absent, if the bark of the tree has been removed in a particular area, the rings will likely be deformed as the plant overgrows the scar.
It is usually lighter in color than that near the portion of the ring. The outer portion formed in the season is known as the latewood or summerwood. However, there are differences, depending on the kind of wood