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Non Polarizing Cube
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52mm Circular Polarizing Filter CPL
$79.99
52mm Circular Polarizing Filter CPL By reducing the light reflected from non-metallic surfaces, polarizing filters allow direct shooting through glass windows and reduce the effect of glare from water surfaces and sunlit trees and grass. In outdoor shooting, the filter can even deal effectively with light reflected on steam or airborne dust particles to enhance the sky's blue color.
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Rokinon 67mm HD Circular Polarizing Filter
$36.35
Rokinon Circular Polarizing (CPL) filters remove unwanted reflections from non-metallic surfaces such as water and glass Photo filter does not affect overall color balanceCamera accessory makes images appear clearerBetter contrast and improved color saturation, such as with blue skies and white cloudsFilters also provide protection from the lens and are ideal for digital and traditional 35mm cameras, including for black and white photographySize: 67 mm
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Cube
$19.99
Cube - Poster
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BasAcc 58mm Circular Polarizing Lens Filter
$18.69
This 58mm Circular Polarizing Lens (CPL) provides color and contrast enhancement.Removes unwanted reflections from non-metallic surfacesIncreases color saturation, creating deep, rich scenic imagesAdds contrast to blue skies and water shotsFits SLR camera, digital camera, camcorder DVMinimizes hazeFilter can be rotatedDiameter: 58mmColor: BlackThis is an accessory only. The camera is not included.Warning: California residents only, please note per Proposition 65 that this product may contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.
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Black 52mm Circular Polarizing Lens Filter
$16.62
This 52mm circular polarizing lens (CPL) filter provides color and contrast enhancement. This len filter removes unwanted reflections from non-metallic surfaces such as water or glass.Increases color saturation, creating deep, rich scenic imagesAdds contrast to blue skies and water shotsIdeal for outdoor photographyMinimizes hazeFilter can be rotated to determine the amount of reflection to be removedCan be used with both auto focus and manual focus cameras and lensesColor: BlackDiameter: 52mmWarning: California residents only, please note per Proposition 65 that this product may contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.
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Black 55mm Circular Polarizing Lens Filter
$19.24
This 55mm circular polarizing lens (CPL) filter provides color and contrast enhancement. This lens filter removes unwanted reflections from non-metallic surfaces such as water or glass.Increases color saturation, creating deep, rich scenic imagesAdds contrast to blue skies and water shotsIdeal for outdoor photographyMinimizes hazeFilter can be rotated to determine the amount of reflection to be removedCan be used with both auto focus and manual focus cameras and lensesColor: BlackDiameter: 55mmWarning: California residents only, please note per Proposition 65 that this product may contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.
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Fairy Cube 2
$18.5
Ian has become a fairy and must now use the Fairy Cube to stop the lizard-spirit Tokage from controlling his life and preventing any chance of his returning to the non-spirit world.
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Renewable Energy
Renewable energy
Renewable energy is energy generated from natural resources—such as sunlight, wind, rain, tides, and geothermal heat—which are renewable (naturally replenished). In 2006, about 18% of global final energy consumption came from renewables, with 13% coming from traditional biomass, such as wood-burning. Hydroelectricity was the next largest renewable source, providing 3% of global energy consumption and 15% of global electricity generation.
Wind power is growing at the rate of 30 percent annually, with a worldwide installed capacity of 121,000 megawatts (MW) in 2008, and is widely used in European countries and the United States. The annual manufacturing output of the photovoltaics industry reached 6,900 MW in 2008, and photovoltaic (PV) power stations are popular in Germany and Spain. Solar thermal power stations operate in the USA and Spain, and the largest of these is the 354 MW SEGS power plant in the Mojave Desert. The world's largest geothermal power installation is The Geysers in California, with a rated capacity of 750 MW. Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18 percent of the country's automotive fuel. Ethanol fuel is also widely available in the USA.
While most renewable energy projects and production is large-scale, renewable technologies are also suited to small off-grid applications, sometimes in rural and remote areas, where energy is often crucial in human development. Kenya has the world's highest household solar ownership rate with roughly 30,000 small (20–100 watt) solar power systems sold per year.
Some renewable-energy technologies are criticized for being intermittent or unsightly, yet the renewable-energy market continues to grow. Climate-change concerns, coupled with high oil prices, peak oil, and increasing government support, are driving increasing renewable-energy legislation, incentives and commercialization. New government spending, regulation and policies should help the industry weather the 2009 economic crisis better than many other sectors.
Main forms/sources of renewable energy
The majority of renewable energy technologies are powered by the sun. The Earth-Atmosphere system is in equilibrium such that heat radiation into space is equal to incoming solar radiation, the resulting level of energy within the Earth-Atmosphere system can roughly be described as the Earth's "climate." The hydrosphere (water) absorbs a major fraction of the incoming radiation. Most radiation is absorbed at low latitudes around the equator, but this energy is dissipated around the globe in the form of winds and ocean currents. Wave motion may play a role in the process of transferring mechanical energy between the atmosphere and the ocean through wind stress. Solar energy is also responsible for the distribution of precipitation which is tapped by hydroelectric projects, and for the growth of plants used to create biofuels.
Renewable energy flows involve natural phenomena such as sunlight, wind, tides and geothermal heat, as the International Energy Agency explains:
Renewable energy is derived from natural processes that are replenished constantly. In its various forms, it derives directly from the sun, or from heat generated deep within the earth. Included in the definition is electricity and heat generated from solar, wind, ocean, hydropower, biomass, geothermal resources, and biofuels and hydrogen derived from renewable resources.
Each of these sources has unique characteristics which influence how and where they are used.
Wind power
Vestas V80 wind turbines
Airflows can be used to run wind turbines. Modern wind turbines range from around 600 kW to 5 MW of rated power, although turbines with rated output of 1.5–3 MW have become the most common for commercial use; the power output of a turbine is a function of the cube of the wind speed, so as wind speed increases, power output increases dramatically. Areas where winds are stronger and more constant, such as offshore and high altitude sites, are preferred locations for wind farms. Typical capacity factors are 20-40%, with values at the upper end of the range in particularly favourable sites.
Globally, the long-term technical potential of wind energy is believed to be five times total current global energy production, or 40 times current electricity demand. This could require large amounts of land to be used for wind turbines, particularly in areas of higher wind resources. Offshore resources experience mean wind speeds of ~90% greater than that of land, so offshore resources could contribute substantially more energy. This number could also increase with higher altitude ground-based or airborne wind turbines.
Wind power is renewable and produces no greenhouse gases during operation, such as carbon dioxide and methane.
Water power
Energy in water (in the form of kinetic energy, temperature differences or salinity gradients) can be harnessed and used. Since water is about 800 times denser than air, even a slow flowing stream of water, or moderate sea swell, can yield considerable amounts of energy.
One of 3 Pelamis P-750 Ocean Wave Power machines in the harbor of Peniche, Portugal
There are many forms of water energy:
- Hydroelectric energy is a term usually reserved for large-scale hydroelectric dams. Examples are the Grand Coulee Dam in Washington State and the Akosombo Dam in Ghana.
- Micro hydro systems are hydroelectric power installations that typically produce up to 100 kW of power. They are often used in water rich areas as a Remote Area Power Supply (RAPS). There are many of these installations around the world, including several delivering around 50 kW in the Solomon Islands.
- Damless hydro systems derive kinetic energy from rivers and oceans without using a dam.
- Ocean energy describes all the technologies to harness energy from the ocean and the sea:
- Marine current power. Similar to tidal stream power, uses the kinetic energy of marine currents
- Ocean thermal energy conversion (OTEC) uses the temperature difference between the warmer surface of the ocean and the colder lower recesses. To this end, it employs a cyclic heat engine. OTEC has not been field-tested on a large scale.
- Tidal power captures energy from the tides.
- Wave power uses the energy in waves. Wave power machines usually take the form of floating or neutrally buoyant structures which move relative to one another or to a fixed point.
- Osmotic power or salinity gradient power, is the energy retrieved from the difference in the salt concentration between seawater and river water. Reverse electrodialysis (PRO) is in the research and testing phase.
- Vortex power is generated by placing obstacles in rivers in order to cause the formation of vortices which can then be tapped for energy.
Solar energy
Monocrystalline solar cell
In this context, "solar energy" refers to energy that is collected from sunlight. Solar energy can be applied in many ways, including to:
- Generate electricity using photovoltaic solar cells.
- Generate electricity using concentrating solar power.
- Generate electricity by heating trapped air which rotates turbines in a Solar updraft tower.
- Generate hydrogen using photoelectrochemical cells.
- Heat water or air for domestic hot water and space heating needs using solar-thermal panels.
- Heat buildings, directly, through passive solar building design.
- Heat foodstuffs, through solar ovens.
- Solar air conditioning
Biofuel
Plants use photosynthesis to grow and produce biomass. Also known as biomatter, biomass can be used directly as fuel or to produce biofuels. Agriculturally produced biomass fuels, such as biodiesel, ethanol and bagasse (often a by-product of sugar cane cultivation) can be burned in internal combustion engines or boilers. Typically biofuel is burned to release its stored chemical energy. Research into more efficient methods of converting biofuels and other fuels into electricity utilizing fuel cells is an area of very active work.
Liquid biofuel Information on pump, California.
Liquid biofuel is usually either a bioalcohol such as ethanol fuel or an oil such as biodiesel or straight vegetable oil. Biodiesel can be used in modern diesel vehicles with little or no modification to the engine. It can be made from waste and virgin vegetable and animal oils and fats (lipids). Virgin vegetable oils can be used in modified diesel engines. In fact the diesel engine was originally designed to run on vegetable oil rather than fossil fuel. A major benefit of biodiesel use is the reduction in net CO2 emissions, since all the carbon emitted was recently captured during the growing phase of the biomass. The use of biodiesel also reduces emission of carbon monoxide and other pollutants by 20 to 40%.
In some areas corn, cornstalks, sugarbeets, sugar cane, and switchgrasses are grown specifically to produce ethanol (also known as grain alcohol) a liquid which can be used in internal combustion engines and fuel cells. Ethanol is being phased into the current energy infrastructure. E85 is a fuel composed of 85% ethanol and 15% gasoline that is sold to consumers. Biobutanol is being developed as an alternative to bioethanol.
Another source of biofuel is sweet sorghum. It produces both food and fuel from the same crop. Some studies have shown that the crop is net energy positive ie. it produces more energy than is consumed in its production and utilization.
Solid biomass Sugar cane residue can be used as a biofuel
Solid biomass is most commonly used directly as a combustible fuel, producing 10-20 MJ/kg of heat. Its forms and sources include wood fuel, the biogenic portion of municipal solid waste, or the unused portion of field crops. Field crops may or may not be grown intentionally as an energy crop, and the remaining plant byproduct used as a fuel. Most types of biomass contain energy. Even cow manure still contains two-thirds of the original energy consumed by the cow. Energy harvesting via a bioreactor is a cost-effective solution to the waste disposal issues faced by the dairy farmer, and can produce enough biogas to run a farm.
With current technology, it is not ideally suited for use as a transportation fuel. Most transportation vehicles require power sources with high power density, such as that provided by internal combustion engines. These engines generally require clean burning fuels, which are generally in liquid form, and to a lesser extent, compressed gaseous phase. Liquids are more portable because they can have a high energy density, and they can be pumped, which makes handling easier.
Non-transportation applications can usually tolerate the low power-density of external combustion engines, that can run directly on less-expensive solid biomass fuel, for combined heat and power. One type of biomass is wood, which has been used for millennia. Two billion people currently cook every day, and heat their homes in the winter by burning biomass, which is a major contributor to man-made climate change global warming. The black soot that is being carried from Asia to polar ice caps is causing them to melt faster in the summer. In the 19th century, wood-fired steam engines were common, contributing significantly to industrial revolution unhealthy air pollution. Coal is a form of biomass that has been compressed over millennia to produce a non-renewable, highly-polluting fossil fuel.
Wood and its byproducts can now be converted through processes such as gasification into biofuels such as woodgas, biogas, methanol or ethanol fuel; although further development may be required to make these methods affordable and practical. Sugar cane residue, wheat chaff, corn cobs and other plant matter can be, and are, burned quite successfully. The net carbon dioxide emissions that are added to the atmosphere by this process are only from the fossil fuel that was consumed to plant, fertilize, harvest and transport the biomass.
Processes to harvest biomass from short-rotation trees like poplars and willows and perennial grasses such as switchgrass, phalaris, and miscanthus, require less frequent cultivation and less nitrogen than do typical annual crops. Pelletizing miscanthus and burning it to generate electricity is being studied and may be economically viable.
Biogas
Biogas can easily be produced from current waste streams, such as paper production, sugar production, sewage, animal waste and so forth. These various waste streams have to be slurried together and allowed to naturally ferment, producing methane gas. This can be done by converting current sewage plants into biogas plants. When a biogas plant has extracted all the methane it can, the remains are sometimes more suitable as fertilizer than the original biomass.
Alternatively biogas can be produced via advanced waste processing systems such as mechanical biological treatment. These systems recover the recyclable elements of household waste and process the biodegradable fraction in anaerobic digesters.
Renewable natural gas is a biogas which has been upgraded to a quality similar to natural gas. By upgrading the quality to that of natural gas, it becomes possible to distribute the gas to the mass market via the existing gas grid.
Geothermal energy
Krafla Geothermal Station in northeast Iceland
Geothermal energy is energy obtained by tapping the heat of the earth itself, both from kilometers deep into the Earth's crust in some places of the globe or from some meters in geothermal heat pump in all the places of the planet . It is expensive to build a power station but operating costs are low resulting in low energy costs for suitable sites. Ultimately, this energy derives from heat in the Earth's core.
Three types of power plants are used to generate power from geothermal energy: dry steam, flash, and binary. Dry steam plants take steam out of fractures in the ground and use it to directly drive a turbine that spins a generator. Flash plants take hot water, usually at temperatures over 200 °C, out of the ground, and allows it to boil as it rises to the surface then separates the steam phase in steam/water separators and then runs the steam through a turbine. In binary plants, the hot water flows through heat exchangers, boiling an organic fluid that spins the turbine. The condensed steam and remaining geothermal fluid from all three types of plants are injected back into the hot rock to pick up more heat.
The geothermal energy from the core of the Earth is closer to the surface in some areas than in others. Where hot underground steam or water can be tapped and brought to the surface it may be used to generate electricity. Such geothermal power sources exist in certain geologically unstable parts of the world such as Chile, Iceland, New Zealand, United States, the Philippines and Italy. The two most prominent areas for this in the United States are in the Yellowstone basin and in northern California. Iceland produced 170 MW geothermal power and heated 86% of all houses in the year 2000 through geothermal energy. Some 8000 MW of capacity is operational in total.
There is also the potential to generate geothermal energy from hot dry rocks. Holes at least 3 km deep are drilled into the earth. Some of these holes pump water into the earth, while other holes pump hot water out. The heat resource consists of hot underground radiogenic granite rocks, which heat up when there is enough sediment between the rock and the earths surface. Several companies in Australia are exploring this technology.
About the Author
S. Rajkumar belongs to Madurai, Tamil nadu, India. He is a post graduate in Computer Science and Information Technology. Now he is working as a web designer and PHP programmer in AJ Square Inc. Vilacherry, Madurai.
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Fused Silica Mirror
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Fused Quartz
$76.47
High Quality Content by WIKIPEDIA articles Fused quartz and fused silica are types of glass containing primarily silica in amorphous (noncrystalline) form. They are manufactured using several different processes. Note that glasses formed by the traditional meltquench methods, are often referred to as vitreous, as in vitreous silica. The term vitreous is synonymous with glass, when used in the meltquench context. Fused quartz is manufactured by melting naturally occurring quartz crystals of high purity at approximately 2000C, using either an electrically heated furnace (electrically fused) or a gas/oxygenfuelled furnace. Fused quartz is normally transparent. Author: Surhone, Lambert M./ Timpledon, Miriam T./ Marseken, Susan F. Binding Type: Paperback Number of Pages: 104 Publication Date: 2010/05/19 Language: English Dimensions: 5.98 x 9.01 x 0.24 inches
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Rational Design of Cellular Silica Composites
$149.76
This book provides a comprehensive study on the design throughout processstructureproperty correlation of the cellular silica constructs with an emphasis on the influence of the porous architecture on intended foam properties with following features: i) Provides a technology featuring 118 figures and 22 tables aiding towards the design and fabrication of cellular ceramics with manual solution available; ii) Slurry based processing route involving the use of hydrophobized fused silica with two different foam stabilization routes, in amalgamation with direct foaming method (to generate porous architecture) has been optimized; iii) As a major accomplishment,random dispersion of quartz fibers (aspect ratio >1000) up to 10 wt has been achieved in the silica based composite foams, through a novel dispersion route, and (iv) Porous composite foams (100 x 100 x 25 mm) have been fabricated successfully through direct foaming route with negligible fiber entanglement and internal defects. It can be an ideal reference text for technologists involved in research and development of cellular ceramic architectures for high temperature thermal protection system applications. Author: Mishra, Sarika Binding Type: Paperback Number of Pages: 212 Publication Date: 2010/06/08 Language: English Dimensions: 5.98 x 9.01 x 0.48 inches
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Silica Gel
$79.66
High Quality Content by WIKIPEDIA articles High Quality Content by WIKIPEDIA articles Silica gel is a granular, vitreous, highly porous form of silica made synthetically from sodium silicate. Despite its name, silica gel is a solid. It is a naturally occurring mineral that is purified and processed into either granular or beaded form. As a desiccant, it has an average pore size of 24 angstroms and has a strong affinity for moisture molecules. Silica gel is most commonly encountered in everyday life as beads packed in a vaporpermeable plastic. In this form, it is used as a desiccant to control local humidity in order to avoid spoilage or degradation of some goods. Because of poisonous dopants (see below) and their very high absorption of moisture, silica gel packets usually bear warnings for the user not to eat the contents. Author: Surhone, Lambert M./ Tennoe, Mariam T./ Henssonow, Susan F. Binding Type: Paperback Number of Pages: 18 Publication Date: 2010/08/22 Language: English Dimensions: 6.00 x 9.02 x 0.04 inches
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Garden of Silica
$30.03
Garden of Silica is the first poetry anthology of the Uruguayan Ida Vitale to appear in English, spanning eight books published from 1960 to the present. Her work seeks a balance between subjectivity and objectivity, privileges intellectual capacity above that of sentimentality, and requires an active reader. Placing the intellectual subject at the forefront, Vitales poetry offers one of the most provocative representations of womens subjectivity in the Spanish language. Author: Vitale, Ida/ Hedeen, Katherine M./ Rodrguez Nez, Vctor Binding Type: Paperback Number of Pages: 140 Publication Date: 2010/01/06 Language: English Dimensions: 8.50 x 5.51 x 0.33 inches
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Mas Epoxies Colloidal Silica Silica, .5 Gallon
$23.99
Mas Epoxies Colloidal Silica Silica, .5 Gallon . Fumed Colloidal Silica (also known as CAB-0-SIL) Use when an extremely hard solid with high density is needed, i.e. structural bonding, filling and filleting. Add strength to a top coat by using a small amount of Colloidal Silica ( about a tablespoon per 4 ounces). This will add strength and finish absolutely clear. The white color in the mixing cup will disappear when it cures.
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About Roman glass jewelry from Israel. Sterling silver and roman glass designs
Roman Glass is an ancient glass, discovered in archaeological excavation sites in Israel and in other Mediterranean countries.The fine Sterling Silver Roman Glass Jewelry is one of the most popular types and styles originated from Israel enabling to wear an entirely unique piece of 2,000-year-old history.
The glass in this aqua-hued jewelry began life as a vase, jug, or vessel. Uncovered from ancient Roman archaeological sites in modern-day Israel, each fragment has been textured and colored by centuries of wind and weather. Each bears the marks of not only its past life as a household or temple object but also the very earth in which it rested until being transformed into a unique accent. Each piece of Roman glass is framed by a sterling silver bezel to create a unique roman glass jewel.
The designs for the jewels are based on artifacts and drawings also discovered on the archeological digs. The Roman Glass is a beautiful piece of history dating back 2,000 years to the time of the Roman Empire. The Roman Glass used for jewel today in Israel is found in archeological digs throughout the land of Israel.
The natural phenomenon which the glass has undergone over the many years it has been buried have given it the unique and beautiful aqua shades we enjoy today in earrings , necklaces and bracelets. Initially, in the Roman empire, glass was mainly used for vessels and available only for the wealthy.
At that time, glass was manufactured by core forming, casting, cutting and grinding. However, since the invention of the glass blowing, glass was available to the public in vast numbers, mass produced in a large variety of shapes and forms. Due to the great popularity of glass during those ancient times, we today are priviliged to make use of these gorgeous historical pieces with which we enhance the beauty of our roman glass jewelry. Ancient Israel, due to its large stretches of sandy dunes and beaches, was one of the largest glass producers of the Roman Empire.
These same sands helped preserve the glass through the centuries, shaping and tempering it into the jewelry-quality pieces being excavated today. Today the fragments of the 2000 years old roman glass that were once part of the lip of a goblet, jar, or other vessel are used in Israel to create beautiful jewelry that mixes the typical blue and green old glass excavated from archaeological digs with silver or gold creating a piece of art and history to wear with love. A certificate of authenticity is available for the Roman Glass jewelry.
It is interesting to know some facts about the glass history and the Roman Glass history, collected from several sources. The History of Glass Glass is formed when sand (silica), soda (alkali), and lime are fused at high temperatures. The color of the glass can be altered by adjusting the atmosphere in the furnace and by adding specific metal oxides to the glass "batch" (such as cobalt for dark blue, tin for opaque white, antimony and manganese for colorless glass).
A venerable legend perpetuated as late as the seventh century A.D. in the writings of Isidore of Seville gives a suitable miraculous explanation for the discovery of this elemental--yet truly wondrous--material - This was its origin: in a part of Syria which is called Phoenicia, there is a swamp close to Judaea, around the base of Mt. Carmel, from which the Bellus River arises . . . whose sands are purified from contamination by the torrent's flow. The story is that here a ship of natron [sodium carbonate] merchants had been shipwrecked; when they were scattered about on the shore preparing food and no stones were at hand for propping up their pots, they brought lumps of natron from the ship.
The sand of the shore became mixed with the burning natron and translucent streams of a new liquid flowed forth: and this was the origin of glass.(Isidore of Seville, Etymologies XVI.16. Translation by Charles Witke.) It is not surprising that the ancient authorities thought of Phoenicia as the birthplace of glass, for the Syro-Palestine region did indeed become a major center of glass production in antiquity, along with Egypt. However, glass seems actually to have been "discovered" not in Phoenicia, but in Mesopotamia. Archaeological research now places the first evidence of true glass there at around 2500 B.C.
At first it was used for beads, seals, and architectural decoration. Some 1,000 years elapsed before glass vessels are known to have been produced. Vessels of glass quickly became widespread in the second half of the second millennium B.C. They were popular not only in Mesopotamia but also in Egypt and the Aegean. The earliest vessels were core-formed. Opaque, dark glass in its molten state was wound around a clay core attached to a metal rod. The skin of hot glass was fashioned with tools in order to shape its external features. Lighter colored strands of hot glass were then trailed on the surface and often "dragged" to produce festoon patterns. The pot surface was marvered (that is, rolled on a smooth, flat surface to produce a level finish). Finally, it was cooled slowly before the clay core was scraped out of the hardened vessel.
This glassware typically imitated forms originally established for ceramic, metal, and stone vessels . Somewhat later, the molding technique was developed, whereby glass chips or molten glass were packed or forced into a mold and then fused. After a molded vessel was annealed (cooled slowly in a special chamber of the glass furnace), it was often ground and polished in order to refine the rim and any other rough edges. One typical shape for molded vessels of the late Hellenistic and early Roman periods (c. 150 -50 B.C.) was the so-called pillar-molded bowl. Here exterior ribs radiate up from the base, stopping abruptly near the rim to allow a smooth margin around the circumference.
This type is ubiquitous; and it attests to the free and rapid exchange of ideas in glass-making throughout the Greater Mediterranean sphere. The site of Tel Anafa in Israel is a small settlement in the Upper Galilee. During ten seasons of fieldwork between 1968 and 1986, Saul Weinberg and his successor Sharon Herbert oversaw the uncovering of part of a small settlement of the Hellenistic and early Roman periods. In Tel Anafa I, Herbert presents the architecture and the stratigraphic sequence (text and some illustrations in fasc. i, locus summary and plates to Chs. 1 and 2 in fasc. ii). The volume also includes studies by other scholars of the geological setting of the site, the stamped amphora handles, coins, vertebrate fauna, and a single Tyrian sealing. Tel Anafa II, i is devoted to the Hellenistic and Roman pottery.
A future volume (II, ii) will complete the series with publication of the pre-Hellenistic and Islamic pottery, lamps, glass, metalware, stucco, stone tools, and the palaeobotanical remains. Tel Anafa (recently excavated jointly by the Universities of Michigan and Missouri) has provided critical information on the chronological limits of these bowls within the Roman period. Glass vessels were initially available only to the very wealthy and only in rather diminutive sizes.
They were manufactured by core forming, casting, cutting and grinding. The invention of glass blowing around 50 BC brought glass vessels to the general public in vast numbers, mass produced in great variety of forms and hence brought ancient glass into the reach of the modern collector of even modest means. One can nowadays own a Roman glass bowl, or drink from a Roman glass beaker, or wear ancient jewellery where glass was used widely. In 63 BC, the Romans conquered the Syro-Palestine area.
They brought back with them glassmakers to Rome.Soon after, the first transparent glass sheets were produced in Rome. The word vitrum, meaning glass, entered the Latin language.Rome's political, military, and economic dominanace in the Mediterranean world was a major factor in attracting skilled craftsmen to set up workshops in the city, but equally important was the fact that the establishment of the Roman industry roughly coincided with the invention of glassblowing. The new technique led craftsmen to create novel and unique shapes; examples exist of flasks and bottles shaped like foot sandals, wine barrels, fruits, and even helmets and animals. Some combined blowing with glass-casting and pottery-molding technologies to create the so-called mold-blowing process.
Further innovations and stylistic changes saw the continued use of casting and free-blowing to create a variety of open and closed forms that could then be engraved or facet-cut in any number of patterns and designs. Core-formed and cast glass vessels were first produced in Egypt and Mesopotamia as early as the fifteenth century B.C., but only began to be imported and, to a lesser extent, made on the Italian peninsula in the mid-first millennium B.C.
By the time of the Roman Republic (509-27 B.C.), such vessels, used as tableware or as containers for expensive oils, perfumes, and medicines, were common in Etruria (modern Tuscany) and Magna Graecia (areas of southern Italy including modern Campania, Apulia, Calabria, and Sicily). However, there is very little evidence for similar glass objects in central Italian and Roman contexts until the mid-first century B.C. The reasons for this are unclear, but it suggests that the Roman glass industry sprang from almost nothing and developed to full maturity over a couple of generations during the first half of the first century A.D. Doubtless Rome's emergence as the dominant political, military, and economic power in the Mediterranean world was a major factor in attracting skilled craftsmen to set up workshops in the city, but equally important was the fact that the establishment of the Roman industry roughly coincided with the invention of glassblowing.
This invention revolutionized ancient glass production, putting it on a par with the other major industries, such as that of pottery and metalwares (as 20.49.2-12). Likewise, glassblowing allowed craftsmen to make a much greater variety of shapes than before. Combined with the inherent attractiveness of glass-it is nonporous, translucent (if not transparent), and odorless-this adaptability encouraged people to change their tastes and habits, so that, for example, glass drinking cups rapidly supplanted pottery equivalents. In fact, the production of certain types of native Italian clay cups, bowls, and beakers declined through the Augustan period, and by the mid-first century A.D. had ceased altogether.However, although blown glass came to dominate Roman glass production, it did not altogether supplant cast glass. Especially in the first half of the first century A.D., much Roman glass was made by casting, and the forms and decoration of early Roman cast vessels demonstrate a strong Hellenistic influence.
The Roman glass industry owed a great deal to eastern Mediterranean glassmakers, who first developed the skills and techniques that made glass so popular that it can be found on every archaeological site, not only throughout the Roman empire but also in lands far beyond its frontiers. Cast Glass Although the core-formed industry dominated glass manufacture in the Greek world, casting techniques also played an important role in the development of glass in the ninth to fourth centuries B.C. Cast glass was produced in two basic ways-through the lost-wax method and with various open and plunger molds.
The most common method used by Roman glassmakers for most of the open-form cups and bowls in the first century B.C. was the Hellenistic technique of sagging glass (81.10.243) over a convex "former" mold. However, various casting and cutting methods were continuously utilized as style and popular preference demanded. The Romans also adopted and adapted various color and design schemes from the Hellenistic glass traditions, applying such designs as network glass and gold-band glass to novel shapes and forms. Distinctly Roman innovations in fabric styles and colors include marbled mosaic glass, short-strip mosaic glass, and the crisp, lathe-cut profiles of a new breed of fine as monochrome and colorless tablewares of the early empire, introduced around 20 A.D.
This class of glassware became one of the most prized styles because it closely resembled luxury items such as the highly valued rock crystal objects, Augustan Arretine ceramics (as 10.210.37), and bronze and silver tablewares (as 20.49.2-12) so favored by the aristocratic and prosperous classes of Roman society. In fact, these fine wares were the only glass objects continually formed via casting, even up to the as Late Flavian, Trajanic, and Hadrianic periods (96-138 A.D.), after glassblowing superceded casting as the dominant method of glassware manufacture in the early first century A.D. Blown Glass SOMETIME AROUND 70 B.C., in Jerusalem, someone realized that, if you took a glass tube -- then the stock for mass production of beads -- sealed one end and blew into the other, you could create a glass bulb. Blow hard enough and long enough, and you could make a small bottle.
This was glassblowing at its most primitive. It is quite possible that, without further refinement, this moment of experimentation might have passed unnoticed. A couple of decades later, however, the introduction of a separate blowpipe, together with a tool-kit of variously-sized pincers and paddles, made it possible to blow and shape glass with much greater control, and with much greater novelty.
The new technology revolutionized the Italian glass industry, stimulating an enormous increase in the range of shapes and designs that glassworkers could produce. A glassworker's creativity was no longer bound by the technical restrictions of the laborious casting process, as blowing allowed for previously unparalleled versatility and speed of manufacture. These advantages spurred a rapid evolution of style and form, and experimentation with the new technique led craftsmen to create novel and unique shapes; examples exist of flasks and bottles shaped like foot sandals, wine barrels, fruits, and even helmets and animals.
Some combined blowing with glass-casting and pottery-molding technologies to create the so-called mold-blowing process. Further innovations and stylistic changes saw the continued use of casting and free-blowing to create a variety of open and closed forms that could then be engraved or facet-cut in any number of patterns and designs. But the potential of a technological idea will only come to fruition if its seed is planted in an encouraging cultural environment. During Rome's Republican Era, in the dictatorial times of Sulla and Julius Caesar, such encouragement seems to have been lacking. In the Hellenistic world, the firmly established traditions of working glass -- either by blending threads of it into closed vessel forms or by slumping glass over a pre-shaped model for open ones -- were producing fine wares with which the infant technique of free-blowing could not yet compete.
In the Roman world, however, pottery was still the material of choice for everything domestic, from fish platters to perfume bottles, and no one seemed to be in any hurry to change that situation. Enter the Emperor Augustus. It is said that he had no love of foreigners; he viewed the appreciable numbers of them living in Rome around 10 B.C. as a potential source for the corruption of traditional Roman values. If I interpret his subsequent actions correctly, he wanted the Italian mainland to be far more self-sufficient wherever possible. So it was that Italian businesses in certain crafts -- most obviously, pottery- and cloth-making -- were encouraged to expand. The craft of glassworking now was adopted from the Hellenistic world with much energy and skill. An ancient Industrial Revolution was underway.
To get things moving, the Romans simply enslaved hundreds of skilled craftsmen in the eastern provinces, uprooting them from their homes and resettling them in the outskirts of rapidly-growing Roman cities. Pottery-makers were imported from Asia Minor, particularly from around Pergamum, and put to work at Arretium; Greek craftsmen were moved from Athens to Lyons and other cities in central Gaul; glassworkers were brought in from the provinces of Syria, Judaea, and Aegyptus -- most likely from the cities of Sidon, Jerusalem, and Alexandria -- and put to work in shops at Naples, Aquileia, and just outside Rome itself. There was an immediate market niche for glassware in Augustan times.
Like many ancient peoples, the Romans believed in an afterlife that was an idealized form of their worldly experience. According to its means, the family of each dead Roman was obliged to provide furnishings for the grave. Such furnishings always included regular domestic items -- plates of food, flasks of wine, and so on -- but it was also a tradition to include offerings of perfume. The Roman wealthy would put these offerings in bottles (unguentaria) made of silver or alabaster. The eastern craftsmen who brought with them the skill of glassblowing now offered the rest of the population an alternative in glass; to be sure, not something as elegant or colorful as might have been wished, but which everyone could afford. The free-blown unguentarium was one of the immediate and long-term successes of the newly emerging industry. Modern excavations have revealed many instances where a grave contains not just one or two but a couple of dozen of these, all mass-produced, each in a matter of minutes at most.
At the same time, glass captured the popular imagination by virtue of its translucency. You could see the color of wine in a beaker, or how well a bottle was filled even if it was sealed -- which could not be said for items made of pottery, or indeed of bronze, silver, or gold. The production of wine glasses soared in the Augustan era, actually causing the demise of some of the pottery workshops that specialized in traditional beaker types. It was glass's distinctive property of transparency that stimulated the Emperor Nero's tutor, Lucius Seneca to observe that " ... Apples seem more beautiful if they are floating in a glass." (Investigations in Natural Science I.6).
And, from the middle of the first century A.D. onward, squared-sided glass bottles -- typically with capacities in the half- to one-liter range -- were used for a great deal of the short-range movement of liquids such as olive oil and the popular fish sauce known as garum. Thus the industrialization of glassworking in the Augustan era came about through the influence of three distinct forces: First, by virtue of certain historical events (Augustus's rise to power and his promotion of craft-centralization on the Italian mainland); second, because of a technical innovation (the invention of glassblowing in one of Rome's eastern provinces); and third, the social pressure related to fashion or taste (a traditional link between perfumery and Roman funerary ritual). Change in the Roman glassworking industry was always most dramatic whenever all three of these forces came together at one time.
Uses
At the height of its popularity and usefulness in Rome, glass was present in nearly every aspect of daily life-from a lady's morning toilette to a merchant's afternoon business dealings to the evening cena, or dinner. Glass alabastra , unguentaria, and other small bottles and boxes held the various oils, perfumes, and cosmetics used by nearly every member of Roman society. Pyxides often contained jewelry with glass elements such as beads, cameos, and intaglios , made to imitate semi-precious stone like carnelian, emerald, rock crystal, sapphire, garnet, sardonyx, and amethyst. Merchants and traders routinely packed, shipped, and sold all manner of foodstuffs and other goods across the Mediterranean in glass bottles and jars of all shapes and sizes, supplying Rome with a great variety of exotic materials from far-off parts of the empire. Other applications of glass included multicolored tesserae used in elaborate floor and wall mosaics, and mirrors containing colorless glass with wax, plaster, or metal backing that provided a reflective surface. Glass windowpanes were first made in the early imperial period, and used most prominently in the public baths to prevent drafts. Because window glass in Rome was intended to provide insulation and security, rather than illumination or as a way of viewing the world outside, little, if any, attention was paid to making it perfectly transparent or of even thickness.
Window glass could be either cast or blown. Cast panes were poured and rolled over flat, usually wooden molds laden with a layer of sand, and then ground or polished on one side. Blown panes were created by cutting and flattening a long cylinder of blown glass.
AN INDUSTRY THOUGH Roman glassworking certainly was, it was one that maintained a remarkable degree of dynamism over the centuries. The shape and decoration of two of its main products -- the unguentarium and the wine beaker -- were being modified every few decades, sometimes quite sharply, and there were many new items of glassware introduced that expanded the glassworker's repertoire in significant ways. The way that the Romans committed themselves so heavily to the maintenance of good ports all around the Mediterranean coastline and of fine roads that criss-crossed the entire Empire on land was also critical for keeping the Roman glassmaking industry so dynamic.
Of course, the main purpose of such maintenance was to assure the easy movement of troops from one trouble spot to another, and of administrative information from one city to another. But these ports and roads also allowed the movement of people and their ideas. Signatures and inscriptions in Greek indicate clearly enough that eastern Mediterranean craftsmen settled at various places in northern Italy and central Gaul; that north African and Syrian soldiers were conscripted to serve in the army in northern England, thereafter to settle there as tradesmen; and that businessmen of every background and philosophical persuasion traded wherever it was to their advantage to do so. Thus, every Roman city became a social melting-pot where technical innovations could be passed on, blending with or displacing old ideas, sometimes in the space of just a decade or two.
The industrial activities of the Roman world responded accordingly, with a freshness of purpose and an ongoing rise in skill. Jewelry in the Roman Times Ancient Roman glass jewelry reached its height during the Augustan age, at the beginning of the Empire. This meant that in many ways the glass jewelry were deprived of much of the expressive freedom one might expect and hope for. The buyers of this fine artistic jewelry were the conservative political.
The period of peace achieved during the rule of Augustus and Augustus made this possible, especially after the vicious fighting of the Roman civil wars. Ancient Roman jewelry in earlier times was derived from both Hellenistic and Etruscan jewelry. In addition, as Roman jewelry designs freed itself of Hellenistic and Etruscan influences, greater use was made of colored stones such as: topazes, emeralds, rubies, sapphires, and pearls. Trojan and Cretan artisans of the Minoan period, although working at opposite ends of the Aegean region, crafted earrings, bracelets, and necklaces of a common type that persisted from about 2500 BC to the beginning of the Classical period of Greek art 479 BC - 323 BC. Roman jewelry was highly influenced by some of the designs of the places they conquered and established connections with. The creators spared no effort in making some of the most exquisite and ornamental compositions. Rings were a major symbol in the body of ancient Roman jewelry.
Ornamental Roman jewelry was worn by women of high status. They often wore jewelry on their ears, neck, arms and hands. Ancient Roman designs and fashion jewelry also included seal rings, amulets and talismans. The cameo and hoop earrings were introduced in ancient Roman times. Ancient Roman glass jewelry reached its height during the Augustan age, at the beginning of the Empire. This meant that in many ways the glass jewelry were deprived of much of the expressive freedom one might expect and hope for.
The buyers of this fine artistic jewelry were the conservative political. The period of peace achieved during the rule of Augustus and Augustus made this possible, especially after the vicious fighting of the Roman civil wars. The gold beads of ancient Rome were artfully shaped to create images of flowers and animals. The most common fact that is assumed by most is that the ancient Roman jewelry has a similar resembles to the Greek and Etruscan jewelry.
An assortment of Israeli handmade Roman glass jewelry at Bluenoemi Jewelry at the page.
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