Misplaced Pages

#434565

74-605: The earliest predecessor to Holyoke's canals dates to 1827, when the Hadley Falls Company was established to manufacture cotton cloth. Its water-powered looms were fed from a wing dam along the Connecticut River 's Great Rapids. Today's canals began in 1848, after river measurements indicated an available water power of 6,000 cubic feet per second (170 m/s), the equivalent of 30,000 horsepower (22,000 kW), or enough to power 450 mills. That year

148-695: A combination hydro and steam electric power plant on the First Level Canal. Today the canal system is owned by the City of Holyoke and operated by its municipal Gas and Electric Department which bought out the assets of Holyoke Water Power in December 2001. As early as 1995, plans were proposed to create a "canal walk" as part of a "necklace park plan." Styled after the Emerald Necklace , this proposal called for linking Olmsted-designed parks to

222-503: A darning egg and a separate comb-like piece with teeth to hook the warp over; these are used for repairing knitted garments and are like a linear knitting spool . Darning looms were sold during World War Two clothing rationing in the United Kingdom and Canada, and some are homemade. Circular looms are used to create seamless tubes of fabric for products such as hosiery, sacks, clothing, fabric hoses (such as fire hoses) and

296-512: A deck arch bridge. Any part supported from arch below may have spandrels that are closed or open. The Sydney Harbour Bridge and the Bayonne Bridge are a through arch bridge which uses a truss type arch. Also known as a bowstring arch, this type of arch bridge incorporates a tie between two opposite ends of the arch. The tie is usually the deck and is capable of withstanding the horizontal thrust forces which would normally be exerted on

370-462: A greater passage for flood waters. Bridges with perforated spandrels can be found worldwide, such as in China ( Zhaozhou Bridge , 7th century). Greece ( Bridge of Arta , 17th century) and Wales ( Cenarth Bridge , 18th century). In more modern times, stone and brick arches continued to be built by many civil engineers, including Thomas Telford , Isambard Kingdom Brunel and John Rennie . A key pioneer

444-477: A loom that folds into a narrow space when not in use. Loom frames can be roughly divided, by the orientation of the warp threads, into horizontal looms and vertical looms. There are many finer divisions. Most handloom frame designs can be constructed fairly simply. The back-strap loom (also known as belt loom) is a simple loom with ancient roots, still used in many cultures around the world (such as Andean textiles ). It consists of two sticks or bars between which

518-441: A lot of floor space, and full-time professional weavers are unlikely to use them as they are unergonomic. Their cheapness and portability is less valuable to urban professional weavers. In a treadle loom, the shedding is controlled by the feet, which tread on the treadles . The earliest evidence of a horizontal loom is found on a pottery dish in ancient Egypt , dated to 4400 BC. It was a frame loom, equipped with treadles to lift

592-453: A lot of yarn, so the weaver does not need to refill them too often; and to be an ergonomic size and shape for the particular weaver, loom, and yarn. They may also be designed for low friction. At their simplest, these are just sticks wrapped with yarn. They may be specially shaped, as with the bobbins and bones used in tapestry-making (bobbins are used on vertical warps, and bones on horizontal ones). Deck arch bridge An arch bridge

666-448: A quantity of fill material (typically compacted rubble) above the arch in order to increase this dead-weight on the bridge and prevent tension from occurring in the arch ring as loads move across the bridge. Other materials that were used to build this type of bridge were brick and unreinforced concrete. When masonry (cut stone) is used the angles of the faces are cut to minimize shear forces. Where random masonry (uncut and unprepared stones)

740-415: A result, masonry arch bridges are designed to be constantly under compression, so far as is possible. Each arch is constructed over a temporary falsework frame, known as a centring . In the first compression arch bridges, a keystone in the middle of the bridge bore the weight of the rest of the bridge. The more weight that was put onto the bridge, the stronger its structure became. Masonry arch bridges use

814-418: A shed. To create the counter-shed, a heddle-bar is usually used. A heddle-bar is simply a stick placed across the warp and tied to individual warp threads. When it is lifted, it pulls the warp threads it is tied to out of position, creating a shed. A warp-weighted loom (see diagram) typically uses a heddle-bar. It has two upright posts (C); they support a horizontal beam (D), which is cylindrical so that

SECTION 10

#1732775709435

888-591: A single-shaft loom. The different shafts (also called harnesses) must be controlled by some mechanism. While non-rigid heddles generally mean that two shafts are needed even for a plain tabby weave , twill weaves require three or more (depending on the type of twill), and more complex figured weaves require still more harnesses. Treadle looms can control multiple harnessess with multiple treadles. The weaver selects which harnesses are engaged with their feet. One treadle may be connected to more than one harness, and any number of treadles can be engaged at once, meaning that

962-482: A tabletop. others are backstraps looms with a rigid heddle , and very portable. There exist very small hand-held looms known as darning looms. They are made to fit under the fabric being mended, and are often held in place by an elastic band on one side of the cloth and a groove around the loom's darning-egg portion on the other. They may have heddles made of flip-flopping rotating hooks (see Loom#Rotating-hook heddles ) . Other devices sold as darning looms are just

1036-430: A three-hinged bridge has hinged in all three locations. Most modern arch bridges are made from reinforced concrete . This type of bridge is suitable where a temporary centring may be erected to support the forms, reinforcing steel, and uncured concrete. When the concrete is sufficiently set the forms and falseworks are then removed. It is also possible to construct a reinforced concrete arch from precast concrete , where

1110-489: A water wheel. At its origin the canal is 140 feet (43 m) wide with 22 feet (6.7 m) of water depth. It extends eastward about a thousand feet and then sweeps south for more than one mile (1.6 km) to supply the upper tier of mills. The Second Level Canal runs parallel to the First but about 400 feet (120 m) east. It begins at its south end, and runs north for over a mile. For its first 2,000 feet (600 m), it

1184-488: Is 140 feet (43 m) wide, then gradually narrows to 100 feet (30 m). Its average water depth is 15 feet (5 m). The Third Level Canal begins at the south end of the Second Level, but some 12 feet (4 m) lower, and extends 3,550 feet (1,082 m). It is about 100 feet (30 m) wide and 10 feet (3 m) deep, with an average height above the river varying between 23–28 feet (7–9 m). Throughout

1258-424: Is 4.5 miles (7.2 km) in length on three levels. The canals are now used for electrical power generation as the water descends level by level to the river. The First Level Canal contains 12 large gates regulating water coming into the system, each 15 feet (5 m) long by 9 feet (3 m) wide, and weighing more than four tons, and two smaller gates at 11 feet (3 m) by 4.5 feet (1.4 m), all powered by

1332-422: Is a bridge with abutments at each end shaped as a curved arch . Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side, and partially into a vertical load on the arch supports. A viaduct (a long bridge) may be made from a series of arches, although other more economical structures are typically used today. Possibly

1406-399: Is a device that replaces the drawboy, the weaver's helper who used to control the warp threads by pulling on draw threads. "Dobby" is a corruption of "draw boy". Mechanical dobbies pull on the draw threads using pegs in bars to lift a set of levers. The placement of the pegs determines which levers are lifted. The sequence of bars (they are strung together) effectively remembers the sequence for

1480-428: Is a masonry, or stone, bridge where each successively higher course (layer) cantilevers slightly more than the previous course. The steps of the masonry may be trimmed to make the arch have a rounded shape. The corbel arch does not produce thrust, or outward pressure at the bottom of the arch, and is not considered a true arch . It is more stable than a true arch because it does not have this thrust. The disadvantage

1554-432: Is that this type of arch is not suitable for large spans. In some locations it is necessary to span a wide gap at a relatively high elevation, such as when a canal or water supply must span a valley. Rather than building extremely large arches, or very tall supporting columns (difficult using stone), a series of arched structures are built one atop another, with wider structures at the base. Roman civil engineers developed

SECTION 20

#1732775709435

1628-546: Is the same. The word "loom" derives from the Old English geloma , formed from ge- (perfective prefix) and loma , a root of unknown origin; the whole word geloma meant a utensil, tool, or machine of any kind. In 1404 "lome" was used to mean a machine to enable weaving thread into cloth. By 1838 "loom" had gained the additional meaning of a machine for interlacing thread. Weaving is done on two sets of threads or yarns, which cross one another. The warp threads are

1702-409: Is used for narrow work . It is also used to finish edges, weaving decorative selvage bands instead of hemming. There are heddles made of flip-flopping rotating hooks, which raise and lower the warp, creating sheds . The hooks, when vertical, have the weft threads looped around them horizontally. If the hooks are flopped over on side or another, the loop of weft twists, raising one or the other side of

1776-402: Is used they are mortared together and the mortar is allowed to set before the falsework is removed. Traditional masonry arches are generally durable, and somewhat resistant to settlement or undermining. However, relative to modern alternatives, such bridges are very heavy, requiring extensive foundations . They are also expensive to build wherever labor costs are high. The corbel arch bridge

1850-563: Is used to control each warp thread separately, allowing very complex patterns. A drawloom requires two operators, the weaver, and an assistant called a "drawboy" to manage the figure harness. The earliest confirmed drawloom fabrics come from the State of Chu and date c. 400 BC. Some scholars speculate an independent invention in ancient Syria , since drawloom fabrics found in Dura-Europas are thought to date before 256 AD. The draw loom

1924-464: The Romans were – as with the vault and the dome – the first to fully realize the potential of arches for bridge construction. A list of Roman bridges compiled by the engineer Colin O'Connor features 330 Roman stone bridges for traffic, 34 Roman timber bridges and 54 Roman aqueduct bridges , a substantial part still standing and even used to carry vehicles. A more complete survey by

1998-414: The 20th century. 42°12′31″N 72°36′01″W  /  42.2086°N 72.6002°W  / 42.2086; -72.6002 Loom A loom is a device used to weave cloth and tapestry . The basic purpose of any loom is to hold the warp threads under tension to facilitate the interweaving of the weft threads. The precise shape of the loom and its mechanics may vary, but the basic function

2072-601: The Canal District, parks already along the canal, and the historical downtown. By 2015, the Massachusetts Department of Transportation completed a new phase of sidewalk construction alongside the canals, opening the Canal Walk that linked the downtown to the then-new Holyoke station . The canals are drained twice every year, in the spring and fall, to allow for maintenance. Today's canal system

2146-522: The Italian scholar Vittorio Galliazzo found 931 Roman bridges, mostly of stone, in as many as 26 countries (including former Yugoslavia ). Roman arch bridges were usually semicircular , although a number were segmental arch bridges (such as Alconétar Bridge ), a bridge which has a curved arch that is less than a semicircle. The advantages of the segmental arch bridge were that it allowed great amounts of flood water to pass under it, which would prevent

2220-436: The abutments of an arch bridge. The deck is suspended from the arch. The arch is in compression, in contrast to a suspension bridge where the catenary is in tension. A tied-arch bridge can also be a through arch bridge. An arch bridge with hinges incorporated to allow movement between structural elements. A single-hinged bridge has a hinge at the crown of the arch , a two-hinged bridge has hinges at both springing points and

2294-793: The acclaimed Florentine segmental arch bridge Ponte Vecchio (1345) combined sound engineering (span-to-rise ratio of over 5.3 to 1) with aesthetical appeal. The three elegant arches of the Renaissance Ponte Santa Trinita (1569) constitute the oldest elliptic arch bridge worldwide. Such low rising structures required massive abutments , which at the Venetian Rialto bridge and the Fleischbrücke in Nuremberg (span-to-rise ratio 6.4:1) were founded on thousands of wooden piles, partly rammed obliquely into

Holyoke Canal System - Misplaced Pages Continue

2368-416: The arch and the deck is known as the spandrel . If the spandrel is solid, usually the case in a masonry or stone arch bridge, the bridge is called a closed-spandrel deck arch bridge . If the deck is supported by a number of vertical columns rising from the arch, the bridge is known as an open-spandrel deck arch bridge . The Alexander Hamilton Bridge is an example of an open-spandrel arch bridge. Finally, if

2442-400: The arch is built in two halves which are then leaned against each other. Many modern bridges, made of steel or reinforced concrete, often bear some of their load by tension within their structure. This reduces or eliminates the horizontal thrust against the abutments and allows their construction on weaker ground. Structurally and analytically they are not true arches but rather a beam with

2516-422: The arch supports the deck only at the top of the arch, the bridge is called a cathedral arch bridge . This type of bridge has an arch whose base is at or below the deck, but whose top rises above it, so the deck passes through the arch. The central part of the deck is supported by the arch via suspension cables or tie bars, as with a tied-arch bridge . The ends of the bridge may be supported from below, as with

2590-505: The backstrap loom. The warp-weighted loom is a vertical loom that may have originated in the Neolithic period. Its defining characteristic is hanging weights (loom weights) which keep bundles of the warp threads taut. Frequently, extra warp thread is wound around the weights. When a weaver has woven far enough down, the completed section (fell) can be rolled around the top beam, and additional lengths of warp threads can be unwound from

2664-477: The beams can be simply held apart by hooking them behind pegs driven into the ground, with wedges or lashings used to adjust the tension. Pegged looms may, however, also have horizontal sidepieces holding the beams apart. Such looms are easy to set up and dismantle, and are easy to transport, so they are popular with nomadic weavers. They are generally only used for comparatively small woven articles. Urbanites are unlikely to use horizontal floor looms as they take up

2738-625: The bridge an unusually flat profile unsurpassed for more than a millennium. Trajan's bridge over the Danube featured open- spandrel segmental arches made of wood (standing on 40 m-high (130 ft) concrete piers). This was to be the longest arch bridge for a thousand years both in terms of overall and individual span length, while the longest extant Roman bridge is the 790 m-long (2,590 ft) long Puente Romano at Mérida . The late Roman Karamagara Bridge in Cappadocia may represent

2812-451: The bridge from being swept away during floods and the bridge itself could be more lightweight. Generally, Roman bridges featured wedge-shaped primary arch stones ( voussoirs ) of the same in size and shape. The Romans built both single spans and lengthy multiple arch aqueducts , such as the Pont du Gard and Segovia Aqueduct . Their bridges featured from an early time onwards flood openings in

2886-600: The company had failed and had passed into receivership, Alfred Smith purchased at auction its hydraulic system, consisting of the dam, its gate houses, and 2.5 miles (4.0 km) of power canals with a boat lock; some 1,100 acres (445 ha) of land in Holyoke containing mills and other buildings; and the public water supply reservoir and gas plant, each with a distribution system. He formed the Holyoke Water Power Company and sold stock to investors. Over

2960-459: The company was reconstituted, with a capital stock of $ 4,000,000, to create a new manufacturing center based on local river power. Over the next 10 years it would build the area's dam and canal system, lay out industrial, commercial, and residential areas on its 1,100 acres (445 ha) of land, and construct and operate two cotton mills and a factory making textile machinery. In 1848 the first timber crib dam, about 1,000 feet (300 m) in length,

3034-414: The design and constructed highly refined structures using only simple materials, equipment, and mathematics. This type is still used in canal viaducts and roadways as it has a pleasing shape, particularly when spanning water, as the reflections of the arches form a visual impression of circles or ellipses. This type of bridge comprises an arch where the deck is completely above the arch. The area between

Holyoke Canal System - Misplaced Pages Continue

3108-499: The design. Multiple rows of holes are punched on each card and the many cards that compose the design of the textile are strung together in order. It is based on earlier inventions by the Frenchmen Basile Bouchon (1725), Jean Baptiste Falcon (1728), and Jacques Vaucanson (1740). To call it a loom is a misnomer. A Jacquard head could be attached to a power loom or a handloom, the head controlling which warp thread

3182-554: The earliest surviving bridge featuring a pointed arch. In medieval Europe, bridge builders improved on the Roman structures by using narrower piers , thinner arch barrels and higher span-to-rise ratios on bridges. Gothic pointed arches were also introduced, reducing lateral thrust, and spans increased as with the eccentric Puente del Diablo (1282). The 14th century in particular saw bridge building reaching new heights. Span lengths of 40 m (130 ft), previously unheard of in

3256-415: The fell. The nature of the loom frame and the shedding, picking, and battening devices vary. Looms come in a wide variety of types, many of them specialized for specific types of weaving. They are also specialized for the lifestyle of the weaver. For instance, nomadic weavers tend to use lighter, more portable looms, while weavers living in cramped city dwellings are more likely to use a tall upright loom, or

3330-422: The finished cloth can be rolled around it, allowing the loom to be used to weave a piece of cloth taller than the loom, and preserving an ergonomic working height. The warp threads (F, and A and B) hang from the beam and rest against the shed rod (E). The heddle-bar (G) is tied to some of the warp threads (A, but not B), using loops of string called leashes (H). So when the heddle rod is pulled out and placed in

3404-466: The forked sticks protruding from the posts (not lettered, no technical term given in citation), the shed (1) is replaced by the counter-shed (2). By passing the weft through the shed and the counter-shed, alternately, cloth is woven. Heddle-rods are used on modern tapestry looms. Tablet weaving uses cards punched with holes. The warp threads pass through the holes, and the cards are twisted and shifted to created varied sheds. This shedding technique

3478-499: The grounds to counteract more effectively the lateral thrust. In China, the oldest existing arch bridge is the Zhaozhou Bridge of 605 AD, which combined a very low span-to-rise ratio of 5.2:1, with the use of spandrel arches (buttressed with iron brackets). The Zhaozhou Bridge, with a length of 167 feet (51 m) and span of 123 feet (37 m), is the world's first wholly stone open-spandrel segmental arch bridge, allowing

3552-443: The history of masonry arch construction, were now reached in places as diverse as Spain ( Puente de San Martín ), Italy ( Castelvecchio Bridge ) and France ( Devil's bridge and Pont Grand ) and with arch types as different as semi-circular, pointed and segmental arches. The bridge at Trezzo sull'Adda , destroyed in the 15th century, even featured a span length of 72 m (236 ft), not matched until 1796. Constructions such as

3626-412: The intersections of Cabot and Canal Street. Five rail bridges remain operable, including three trusses , along with one defunct deck bridge and another converted into a pedestrian bridge for the Canal Walk. At least two pedestrian bridges, one by Hadley Thread Mill and another by Holyoke Die Cut Card remain closed; another one pedestrian bridge at the corner of Oliver St was demolished in the latter half of

3700-497: The like. Tablet weaving can be used to knit tubes, including tubes that split and join. Small jigs also used for circular knitting are also sometimes called circular looms, but they are used for knitting, not weaving. It is possible to weave by manually threading the weft over and under the warp threads, but this is slow. Some tapestry techniques use manual shedding. Pin looms and peg looms also generally have no shedding devices. Pile carpets generally do not use shedding for

3774-436: The loop, which creates the shed and countershed. Rigid heddles are generally used on single-shaft looms. Odd warp threads go through the slots, and even ones through the circular holes, or vice-versa. The shed is formed by lifting the heddle, and the countershed by depressing it. The warp threads in the slots stay where they are, and the ones in the circular holes are pulled back and forth. A single rigid heddle can hold all

SECTION 50

#1732775709435

3848-636: The newly constructed fabric must be wound onto cloth beam. This process is called taking up. At the same time, the warp yarns must be let off or released from the warp beam, unwinding from it. To become fully automatic, a loom needs a tertiary motion , the filling stop motion. This will brake the loom if the weft thread breaks. An automatic loom requires 0.125 hp to 0.5 hp to operate (100W to 400W). A loom, then, usually needs two beams, and some way to hold them apart. It generally has additional components to make shedding, picking, and battening faster and easier. There are also often components to help take up

3922-404: The next 30 years the company flourished, as a number of large mills were built in the area. Energy was transmitted from the waterwheels to mills via a distribution system of gears, shafts, pulleys, and belts. The canals first produced municipal electricity on October 14, 1884, from an electric generator connected to a water wheel–driven shafting in an industrial building. In 1888 this was replaced by

3996-417: The number of different sheds that can be selected is two to the power of the number of treadles. Eight is a large but reasonable number of treadles, giving a maximum of 2 =256 sheds (some of which will not have enough threads on one side to be useful). The weaver must remember the sequence of treadling needed to produce the pattern. A drawloom is for weaving figured cloth. In a drawloom, a "figure harness"

4070-598: The oldest existing arch bridge is the Mycenaean Arkadiko Bridge in Greece from about 1300 BC. The stone corbel arch bridge is still used by the local populace. The well-preserved Hellenistic Eleutherna Bridge has a triangular corbel arch. The 4th century BC Rhodes Footbridge rests on an early voussoir arch. Although true arches were already known by the Etruscans and ancient Greeks ,

4144-505: The ones stretched on the loom (from the Proto-Indo-European * werp , "to bend" ). Each thread of the weft (i.e. "that which is woven") is inserted so that it passes over and under the warp threads. The ends of the warp threads are usually fastened to beams. One end is fastened to one beam, the other end to a second beam, so that the warp threads all lie parallel and are all the same length. The beams are held apart to keep

4218-586: The pattern. Speed is lower, and shedding and picking devices may be simpler. Looms used for weaving traditional tapestry are called not as "vertical-warp" and "horizontal-warp", but as "high-warp" or "low-warp" (the French terms haute-lisse and basse-lisse are also used in English). Inkle looms are narrow looms used for narrow work . They are used to make narrow warp-faced strips such as ribbons, bands, or tape. They are often quite small; some are used on

4292-849: The piers, e.g. in the Pons Fabricius in Rome (62 BC), one of the world's oldest major bridges still standing. Roman engineers were the first and until the Industrial Revolution the only ones to construct bridges with concrete , which they called Opus caementicium . The outside was usually covered with brick or ashlar , as in the Alcántara Bridge . The Romans also introduced segmental arch bridges into bridge construction. The 330 m-long (1,080 ft) Limyra Bridge in southwestern Turkey features 26 segmental arches with an average span-to-rise ratio of 5.3:1, giving

4366-409: The pile, because each pile thread is individually knotted onto the warps, but there may be shedding for the weft holding the carpet together. Usually weaving uses shedding devices. These devices pull some of the warp threads to each side, so that a shed is formed between them, and the weft is passed through the shed. There are a variety of methods for forming the shed. At least two sheds must be formed,

4440-455: The shape of an arch. See truss arch bridge for more on this type. A modern evolution of the arch bridge is the long-span through arch bridge . This has been made possible by the use of light materials that are strong in tension such as steel and prestressed concrete. "The Romans were the first builders in Europe, perhaps the first in the world, fully to appreciate the advantages of the arch,

4514-408: The shed and the countershed. Two sheds is enough for tabby weave ; more complex weaves, such as twill weaves , satin weaves , diaper weaves , and figured (picture-forming) weaves, require more sheds. A shed-rod (shedding stick, shed roll) is simply a stick woven through the warp threads. When pulled perpendicular to the threads (or rotated to stand on edge, for wide, flat shedding rods), it creates

SECTION 60

#1732775709435

4588-477: The threads (those passing through the heddles), and lowering the shaft lowers the same threads — the threads passing through the spaces between the heddles remain in place. A treadle loom for figured weaving may have a large number of harnesses or a control head. It can, for instance, have a Jacquard machine attached to it (see Loom#Shedding methods) . Tapestry can have extremely complex wefts, as different strands of wefts of different colours are used to form

4662-550: The three canals there are 28 bridges carrying cars, pedestrians, and parts of the former Holyoke & Westfield Railroad, today operated by the Pioneer Valley Railroad . Of these, in total 21 remain operable. Five single lane bridges, all on the Third Canal, are closed, with one similar remaining in operation at Gatehouse Road. The oldest bridge in the system is the stone deck arch bridge , built in 1894, at

4736-578: The warp beam, and the woven portion of the cloth is rolled up onto the cloth beam (which is also called the takeup roll ). The portion of the fabric that has already been formed but not yet rolled up on the takeup roll is called the fell . Not all looms have two beams. For instance, warp-weighted looms have only one beam; the warp yarns hang from this beam. The bottom ends of the warp yarns are tied to dangling loom weights. A loom has to perform three principal motions : shedding, picking, and battening. There are also usually two secondary motions , because

4810-400: The warp threads taut. The textile is woven starting at one end of the warp threads, and progressing towards the other end. The beam on the finished-fabric end is called the cloth beam . The other beam is called the warp beam . Beams may be used as rollers to allow the weaver to weave a piece of cloth longer than the loom. As the cloth is woven, the warp threads are gradually unrolled from

4884-416: The warp threads, leaving the weaver's hands free to pass and beat the weft thread. A pit loom has a pit for the treadles, reducing the stress transmitted through the much shorter frame. In a wooden vertical-shaft loom, the heddles are fixed in place in the shaft. The warp threads pass alternately through a heddle, and through a space between the heddles (the shed ), so that raising the shaft raises half

4958-450: The warp threads, though sometimes multiple rigid heddles are used. Treadles may be used to drive the rigid heddle up and down. Rigid heddles (above) are called "rigid" to distinguish them from string and metal heddles, where each warp thread has its own heddle, which has an eye at each end and one in the middle for the warp thread. The eyes in the ends are fastened to a shaft, all in a row. This requires multiple shafts; it cannot be done on

5032-563: The warps are stretched. One bar is attached to a fixed object and the other to the weaver, usually by means of a strap around the weaver's back. The weaver leans back and uses their body weight to tension the loom. Both simple and complex textiles can be woven on backstrap looms. They produce narrowcloth : width is limited to the weaver's armspan. They can readily produce warp-faced textiles, often decorated with intricate pick-up patterns woven in complementary and supplementary warp techniques, and brocading. Balanced weaves are also possible on

5106-400: The weaver. Computer-controlled dobbies use solenoids instead of pegs. The Jacquard loom is a mechanical loom, invented by Joseph Marie Jacquard in 1801, which simplifies the process of manufacturing figured textiles with complex patterns such as brocade , damask , and matelasse . The loom is controlled by punched cards with punched holes, each row of which corresponds to one row of

5180-408: The weights to continue. This frees the weaver from vertical size constraint. Horizontally, breadth is limited by armspan; making broadwoven cloth requires two weavers, standing side by side at the loom. Simple weaves, and complex weaves that need more than two different sheds, can both be woven on a warp-weighted loom. They can also be used to produce tapestries. [REDACTED] In pegged looms,

5254-402: Was Jean-Rodolphe Perronet , who used much narrower piers, revised calculation methods and exceptionally low span-to-rise ratios. Different materials, such as cast iron , steel and concrete have been increasingly used in the construction of arch bridges. Stone, brick and other such materials are strong in compression and somewhat so in shear , but cannot resist much force in tension . As

5328-421: Was constructed across the Connecticut River to divert water into the canals. It failed within hours, and was replaced by a second timber dam, which in turn was replaced in 1900 by a granite-faced dam about 150 feet (46 m) downstream from its predecessor. The early canals were dug by men with picks and shovels, together with horse-drawn teams. Canal construction continued on and off until 1892. In 1859, after

5402-510: Was invented in China during the Han dynasty ( State of Liu ?); foot-powered multi-harness looms and jacquard looms were used for silk weaving and embroidery, both of which were cottage industries with imperial workshops. The drawloom enhanced and sped up the production of silk and played a significant role in Chinese silk weaving. The loom was introduced to Persia, India, and Europe. A dobby head

5476-402: Was raised during shedding. Multiple shuttles could be used to control the colour of the weft during picking. The Jacquard loom is the predecessor to the computer punched card readers of the 19th and 20th centuries. The weft may be passed across the shed as a ball of yarn, but usually this is too bulky and unergonomic. Shuttles are designed to be slim, so they pass through the shed; to carry

#434565