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glass
glass hard substance, usually brittle and transparent, composed chiefly of silicates and an alkali fused at high temperature.
Composition and Properties of Glass
Most glass is a mixture of silica obtained from beds of fine sand or from pulverized sandstone; an alkali to lower the melting ...
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Avilés
Avilés , town (1990 pop. 88,429), Oviedo prov., NW Spain, in Asturias, on the Bay of Biscay. Coal is exported. There are iron, steel, and aluminum plants and a large glass factory.
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silicate
silicate chemical compound containing silicon, oxygen, and one or more metals, e.g., aluminum, barium, beryllium, calcium, iron, magnesium, manganese, potassium, sodium, or zirconium. Silicates may be considered chemically as salts of the various silicic acids. For a long time classified as ortho-,...
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mirror
mirror in optics, a reflecting surface that forms an image of an object when light rays coming from that object fall upon it (see reflection ). Usually mirrors are made of plate glass, one side of which is coated with metal or some special preparation to serve as a reflecting surface. The juncti...
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Portland vase
Portland vase a Roman glass vase, known also as the Barberini vase. It is an unusually fine work of the late Augustan era (early 1st cent. BC). About 10 in. (25 cm) high and 22 in. (56 cm) in circumference, it is made of a deep, violet-blue glass overlaid with opaque, white glass into which figures...
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Hannah Glasse
Hannah Glasse , fl. 1747, writer of a popular English cookbook, Art of Cookery (1747). She is also credited with writing The Compleat Confectioner and The Servant's Directory, both published in 1770.
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annealing
annealing , process in which glass, metals, and other materials are treated to render them less brittle and more workable. Annealing consists of heating the material and then cooling it very slowly and uniformly; the time and temperatures required in the process are set according to the properties d...
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hourglass
hourglass glass instrument for measuring time, usually consisting of two bulbs united by a narrow neck. One bulb is filled with fine sand that runs through the neck into the other bulb in an hour's time. The date of its invention is unknown, but it was in use in ancient times. Similar devices for m...
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vinyl plastics
vinyl plastics group of thermoplastics used in molded products, flexible tubing, material for raincoats, and laminated safety glass. Vinyl plastics are polymers and copolymers of vinyl derivatives (i.e., derivatives of ethylene, H 2 C[symbol]CH 2 ), e.g., vinyl chloride (H 2 C=CHCl) and vinyl a...
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contact lens
contact lens thin plastic lens worn between the eye and eyelid that may be used instead of eyeglasses. Actors, models, and others wear them for appearance, and athletes use them for safety and convenience. Contact lenses may also be used to correct certain abnormalities of the eye that cannot be co...
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