Mercury glass

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English mercury glass objects GroupMercuryCover3.JPG
English mercury glass objects

[1] Mercury glass (or silvered glass) is glass that was blown double walled, then silvered between the layers with a liquid silvering solution, and sealed. Although mercury was originally used to provide the reflective coating for mirrors, elemental mercury was never used to create tableware. Silvered glass was free-blown, then silvered with a solution containing silver nitrate and grape sugar in solution, heated, then closed. Sealing methods include metal discs covered with a glass round or a cork inserted into the unpolished pontil scar. "Mercury" silvered glass was produced originally around 1840 until at least 1930 in Bohemia (now the Czech Republic), Germany and was also manufactured in England from 1849 to 1855. Edward Varnish and Frederick Hale Thomson patented the technique for silvering glass vessels in 1849. The English examples were often cased with a layer of colored glass then cut to silver as illustrated in the photograph.

Glass amorphous solid that exhibits a glass transition when heated towards the liquid state

Glass is a non-crystalline, amorphous solid that is often transparent and has widespread practical, technological, and decorative uses in, for example, window panes, tableware, and optoelectronics. The most familiar, and historically the oldest, types of manufactured glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. The term glass, in popular usage, is often used to refer only to this type of material, which is familiar from use as window glass and in glass bottles. Of the many silica-based glasses that exist, ordinary glazing and container glass is formed from a specific type called soda-lime glass, composed of approximately 75% silicon dioxide (SiO2), sodium oxide (Na2O) from sodium carbonate (Na2CO3), calcium oxide (CaO), also called lime, and several minor additives.

Mercury (element) Chemical element with atomic number 80

Mercury is a chemical element with symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum. A heavy, silvery d-block element, mercury is the only metallic element that is liquid at standard conditions for temperature and pressure; the only other element that is liquid under these conditions is the halogen bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature.

Silver nitrate Chemical compound

Silver nitrate is an inorganic compound with chemical formula AgNO
3. This compound is a versatile precursor to many other silver compounds, such as those used in photography. It is far less sensitive to light than the halides. It was once called lunar caustic because silver was called luna by the ancient alchemists, who believed that silver was associated with the moon.

Blown glass is made utilizing a long metal blowpipe by the glass blower who shapes and heats the object. The piece is attached to a long, flat-topped iron called a pontil to the end of the piece, with a small piece of molten glass, and the blowpipe is now cracked off. The workman completes the object and then, the pontil rod or "punty" is cracked off leaving the familiar rough pontil scar.

Companies in the United States, including the Boston and Sandwich Glass Company, New England Glass Company, Union Glass Co., and the Boston Silver Glass Company, made silvered glass from about 1852–1880. The New England Glass Company displayed a variety of silvered glass articles including copper wheel engraved goblets, vases and other tableware at the 1853 New Crystal Palace Exhibition.

Boston and Sandwich Glass Company

The Boston and Sandwich Glass Company was incorporated in 1826 to hold the glass factory built a year earlier in Sandwich, Massachusetts, by Deming Jarves. The factory was closed in 1888 amid disputes with a newly formed glassmakers' labor union.

New England Glass Company

The New England Glass Company (1818–1878), originally founded in Cambridge, Massachusetts and subsequently relocated to Toledo, Ohio, was established by Amos Binney, Edmund Munroe, Daniel Hastings, and Deming Jarves on February 16, 1818. It was renamed the Libbey Glass Company in 1892, then was bought by Owens-Illinois Glass Company, which spun it off as an independent company in 1993. The company produced both blown and pressed glass objects in a variety of colors, which had engraved, cut, etched, and gilded decorations. The firm was one of the first glass companies to use a steam engine to operate its cutting machines, and it built the only oven in the country that could manufacture red lead, a key ingredient in the making of flint glass. By the middle of the nineteenth century, the New England Glass Company was considered one of the leading glasshouses in the United States, best known for its cut and engraved glass.

Silvered mercury glass from Bohemia was also decorated with a variety of techniques including painting, enameling, etching, and surface engraving.

Silvered "mercury" glass is considered one of the first true "art glass" types, that is, glass that was made for display and for its inherent artistic value rather than for utilitarian use.

Authentic antique silvered glass pieces are still available in a wide range of decorative items and usually sold as mercury glass.

There are many reproductions currently marketed as "mercury glass", in table form, ornaments and other objects. New "mercury glass" can be distinguished from antique silvered glass in several ways, including lack of a double wall, and solid bottoms that are different from true antique silvered glass. [2] [3]

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Mirror object that reflects light or sound

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Pewter is a malleable metal alloy. It is traditionally composed of 85–99% tin, mixed with copper, antimony, bismuth, and sometimes silver. Copper and antimony act as hardeners while lead is more common in the lower grades of pewter, which have a bluish tint. Pewter has a low melting point, around 170–230 °C (338–446 °F), depending on the exact mixture of metals. The word pewter is probably a variation of the word spelter, a term for zinc alloys.

Glassblowing glassforming technique that involves inflating molten glass into a bubble, with the aid of a blowpipe

Glassblowing is a glassforming technique that involves inflating molten glass into a bubble with the aid of a blowpipe. A person who blows glass is called a glassblower, glassmith, or gaffer. A lampworker manipulates glass with the use of a torch on a smaller scale, such as in producing precision laboratory glassware out of borosilicate glass.

Gilding covering object with layer of gold

Gilding is any decorative technique for applying a very thin coating of gold to solid surfaces such as metal, wood, porcelain, or stone. A gilded object is also described as "gilt". Where metal is gilded, it was traditionally silver in the West, to make silver-gilt objects, but gilt-bronze is commonly used in China, and also called ormolu if it is Western. Methods of gilding include hand application and gluing, typically of gold leaf, chemical gilding, and electroplating, the last also called gold plating. Parcel-gilt objects are only gilded over part of their surfaces. This may mean that all of the inside, and none of the outside, of a chalice or similar vessel is gilded, or that patterns or images are made up by using a combination of gilt and ungilted areas.

Mercury silvering

Mercury silvering or fire gilding is a silvering technique for applying a thin layer of precious metal such as silver or gold to a base metal object. The process was invented during the Middle Ages and is documented in Vannoccio Biringuccio's 1540 book De la pirotechnia. An amalgam of mercury and the precious metal is prepared and applied to the object which is then heated, sometimes in oil, vaporizing most of the mercury. The technique is dangerous since mercury is highly toxic, especially in its vapor phase. Mercury silvering can be detected through a variety of methods.

Plating is a surface covering in which a metal is deposited on a conductive surface. Plating has been done for hundreds of years; it is also critical for modern technology. Plating is used to decorate objects, for corrosion inhibition, to improve solderability, to harden, to improve wearability, to reduce friction, to improve paint adhesion, to alter conductivity, to improve IR reflectivity, for radiation shielding, and for other purposes. Jewelry typically uses plating to give a silver or gold finish.

Lampworking ype of glasswork where a torch or lamp is primarily used to melt the glass

Lampworking is a type of glasswork where a torch or lamp is primarily used to melt the glass. Once in a molten state, the glass is formed by blowing and shaping with tools and hand movements. It is also known as flameworking or torchworking, as the modern practice no longer uses oil-fueled lamps. Although lack of a precise definition for lampworking makes it difficult to determine when this technique was first developed, the earliest verifiable lampworked glass is probably a collection of beads thought to date to the fifth century BC. Lampworking became widely practiced in Murano, Italy in the 14th century. In the mid 19th century lampwork technique was extended to the production of paperweights, primarily in France, where it became a popular art form, still collected today. Lampworking differs from glassblowing in that glassblowing uses a furnace as the primary heat source, although torches are also used.

Silvering is the chemical process of coating glass with a reflective substance. When glass mirrors first gained widespread usage in Europe during the 16th century, most were silvered with an amalgam of tin and mercury, but by the 19th century, mirrors were commonly made through a process by which silver was coated onto a glass surface. Today, sputtering aluminium or other compounds is more often used for this purpose, although the process may maintain the name "silvering".

The term "opaline" in current times refers to many forms of opaque and colored glass. In France the term opaline is used to refer to multiple types of glass and not specifically antique colored crystal or semi-crystal. The idea that the term opaline is strictly antique French crystal is incorrect. For instance when shopping in France you may see a piece of American slag glass for sale labeled opaline in reference to the color of glass and not the age, origin or content of the glass.

Blenko Glass Company American glassmakers

Blenko Glass Company, located in Milton, West Virginia, is known for its artistic hand-blown glass.

Distressing treating theatrical, film or television costumes to make them look worn, damaged, or lived in

Distressing in the decorative arts is the activity of making a piece of furniture or object appear aged and older, giving it a "weathered look", and there are many methods to produce an appearance of age and wear. Distressing is viewed as a refinishing technique although it is the opposite of finishing in a traditional sense. In distressing, the object's finish is intentionally destroyed or manipulated to look less than perfect, such as with sandpaper or paint stripper. For example, the artisan often removes some but not all of the paint, leaving proof of several layers of paint speckled over wood grain underneath. This becomes the "finished" piece.

Caneworking

In glassblowing, cane refers to rods of glass with color; these rods can be simple, containing a single color, or they can be complex and contain strands of one or several colors in pattern. Caneworking refers to the process of making cane, and also to the use of pieces of cane, lengthwise, in the blowing process to add intricate, often spiral, patterns and stripes to vessels or other blown glass objects. Cane is also used to make murrine, thin discs cut from the cane in cross-section that are also added to blown or hot-worked objects. A particular form of murrine glasswork is millefiori, in which many murrine with a flower-like or star-shaped cross-section are included in a blown glass piece.

The firm of James Powell and Sons, also known as Whitefriars Glass, were English glassmakers, leadlighters and stained glass window manufacturers. As Whitefriars Glass, the company existed from the 17th century, but became well known as a result of the 19th century Gothic Revival and the demand for stained glass windows.

Plane mirror

A plane mirror is a mirror with a flat (planar) reflective surface. For light rays striking a plane mirror, the angle of reflection equals the angle of incidence. The angle of the incidence is the angle between the incident ray and the surface normal. Therefore, the angle of reflection is the angle between the reflected ray and the normal and a collimated beam of light does not spread out after reflection from a plane mirror, except for diffraction effects.

Glass-to-metal seal

Glass-to-metal seals are a very important element of the construction of vacuum tubes, electric discharge tubes, incandescent light bulbs, glass encapsulated semiconductor diodes, reed switches, pressure tight glass windows in metal cases, and metal or ceramic packages of electronic components.

The Fostoria Glass Company manufactured pressed, blown and hand-molded glassware and tableware for almost 100 years. It began operations in Fostoria, Ohio, on December 15, 1887, on land donated by the townspeople. The new company was formed by men from West Virginia, who were experienced in the glassmaking business. They started their company in northwest Ohio to take advantage of newly discovered natural gas that was an ideal fuel for glassmaking. Numerous other businesses were started in the area, and the supply of natural gas began to diminish. Fuel shortages caused the company to move to Moundsville, West Virginia in 1891.

A glossary of terms used in glass art

Early American molded glass refers to functional and decorative objects, such as bottles and dishware, that were manufactured in the United States in the 19th century. The objects were produced by blowing molten glass into a mold, thereby causing the glass to assume the shape and pattern design of the mold. Common blown molded tableware items bearing designs include salt dishes, sugar bowls, creamers, celery stands, decanters, and drinking glasses. Household items, other than dishware, made using the three-mold method include inkwells, oil lamps, birdcage fountains, hats, medicine and perfume bottles, and witch balls. Whiskey flasks bearing unique designs were made in two part molds. Undecorated bottles used as containers for a variety of liquids were blown into square molds to give them corners so they could be packed into compartments of wooden cases.

Conservation and restoration of silver objects

The conservation and restoration of silver objects is an activity dedicated to the preservation and protection of objects of historical and personal value made from silver. When applied to cultural heritage this activity is generally undertaken by a conservator-restorer.

Pairpoint Glass

Pairpoint Glass Company is an American glass manufacturer based in Sagamore, Massachusetts. It is currently the oldest operating glass company in the United States.

References

  1. ↑ PICTORIAL GUIDE TO SILVERED MERCURY GLASS
  2. ↑ Pictorial Guide To Silvered Mercury Glass
  3. ↑ "Pictorial Guide To Silvered Mercury Glass," Lytwyn, Diane. Collector Books 2006
  1. ↑ "Pictorial Guide to Silvered Mercury Glass", 2007
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