What makes Viviano's installation into a viewing experience is the fine craftwork of the glass pendants, which also resemble the plumb bobs used in construction work.
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Chalk lines and plumb-bobs are often sold as a single tool.
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During subsequent triangulation, errors due to atmospheric refraction, deflection of plumb-bobs, temperature, and the spherical nature of the earth (meaning there were more than 180 degrees in a triangle) were all allowed for.
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On top of the beam, a groove or channel was carved. If the condition was too windy for the plumb bobs to work effectively, the surveyor could pour water into the groove and measure the plane by checking the water level.
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Mestayer's design was accepted, which lead to a construction contract being issued on 13 July 1903 to McWilliams and Andrews to build the scheme. The tunnel was dug from the outlet, from a side drive about 16 chains (322 metres) from the outlet, and from a deep shaft about 21 chains (422 metres) from the outlet. From the side drive and also from the shaft the tunnel was driven in both directions. The alignment of the tunnel was laid out on the surface by Sladden & Palmer, Civil Engineers and Surveyors, and then transferred to the bottom of the shaft by means of heavy plumb bobs suspended from the top by very fine wires, with the plumb bobs themselves hanging in buckets of water to dampen their movement.
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A trial well is then dug to determine the location of the water table and determine whether a sufficient flow is available to justify construction. If these prerequisites are met, the route is laid out aboveground. Equipment must be assembled. The equipment is straightforward: containers (usually leather bags), ropes, reels to raise the container to the surface at the shaft head, hatchets and shovels for excavation, lights, spirit levels or plumb bobs and string.
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The architect and engineer may look for signs of cracking of masonry wall or the settling of basement floors or upper floors which direct them to a problem in the foundation. These signs can also be detected from window sills and cornices. Appropriate survey instruments such as plumb bobs and spirit levels are recommended for use instead of a naked eye inspection. If the problem seems too severe, a test boring may reveal the cause of the problem.
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Until the modern age, plumb bobs were used on most tall structures to provide vertical datum lines for the building measurements. A section of the scaffolding would hold a plumb line, which was centered over a datum mark on the floor. As the building proceeded upward, the plumb line would also be taken higher, still centered on the datum. Many cathedral spires, domes and towers still have brass datum marks inlaid into their floors, which signify the center of the structure above.
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Before the invention of the pointing machine by Gatteaux, sculptors used several methods to measure and copy sculpture, such as grids,Cami/Santamera, Sculpture In Stone which were already in use in early Egyptian sculpture, plumb-bobs, measuring sticks and calipers. The main technique was to measure the model from three fixed points with calipers. Nowadays laser pointing machines are available. These have the advantages that the needle does not hinder carving and that the sculptor is given an audible warning when the right depth is reached.
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Ancient Egyptians were among the first to use minerals such as sulfur as cosmetic substances. The Egyptians worked deposits of the lead ore galena at Gebel Rosas to make net sinkers, plumb bobs, and small figurines. Copper was the most important metal for toolmaking in ancient Egypt and was smelted in furnaces from malachite ore mined in the Sinai. Workers collected gold by washing the nuggets out of sediment in alluvial deposits, or by the more labor-intensive process of grinding and washing gold- bearing quartzite.
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Plumb bob with scale as an inclinometer A plumb bob and line alone can determine only a vertical reference. However, if they are mounted on a suitable scale the instrument may also be used as an inclinometer to measure angles to the vertical. The early skyscrapers used heavy plumb bobs, hung on wire in their elevator shafts. A plumb bob may be in a container of water (when conditions are above freezing temperatures), molasses, very viscous oils or other liquids to dampen any swinging movement,Staley, W. W.. Introduction to mine surveying,.
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The line thus transferred was produced in both directions by means of a theodolite. The line was marked inside the tunnel by iron spikes driven into the roof, and from which plumb bobs were suspended to guide the excavation. The levels were transferred from, the surface to the bottom of the shaft using a long steel tape, and then maintained as the work progressed by means of an engineer's level. The power scheme received a licence from the government to generate electricity on 24 February 1905, and was completed in late 1905.
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A pointing 'machine' and its crosswood The pointing needle and stop Copying a plaster cast of a bust in red sandstone. Workshop of the Strasbourg cathedral router carving a sculpture from a block of marble 15th Century measuring device with plumb-bobs A pointing machine is a measuring tool used by stone sculptors and woodcarvers to accurately copy plaster, clay or wax sculpture models into wood or stone. In essence the device is a pointing needle that can be set to any position and then fixed. It further consists of brass or stainless steel rods and joints which can be placed into any position and then tightened.
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Apollo Belvedere, (350-325 BC) Vatican Museums Titian, Assumption of the Virgin (1516–1518) Sight-Size is a method of drawing and painting an object exactly as it appears to the artist, on a one- to-one scale. The artist first sets a vantage point where the subject and the drawing surface appear to be the same size. Then, using a variety of measuring tools—which can include levels, mirrors, plumb bobs, strings, and sticks—the artist draws the subject so that, when viewed from the set vantage point, the drawing and the subject have exactly the same dimensions. When properly done, sight-size drawing can result in extremely accurate and realistic drawings.
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