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Telford, Thomas

(Encyclopedia)Telford, Thomas, 1757–1834, Scottish civil engineer. He greatly improved road building in England and Scotland. He introduced the use of a base of large stones surfaced with compacted layers of smal...

emerald

(Encyclopedia)emerald, the green variety of beryl, of which aquamarine is the blue variety. Chemically, it is a beryllium-aluminum silicate whose color is due to small quantities of chromium compounds. The emerald ...

Deucalion

(Encyclopedia)Deucalion dyo͞okāˈlēən [key], in Greek mythology, son of Prometheus and father of Hellen. When Zeus, angered by humanity's irreverence, flooded the earth, Deucalion, warned by Prometheus, survive...

tonsils

(Encyclopedia)tonsils, name commonly referring to the palatine tonsils, two ovoid masses of lymphoid tissue situated on either side of the throat at the back of the tongue. The pharyngeal tonsils, or adenoids, are ...

topaz

(Encyclopedia)topaz tōˈpăz [key], aluminum silicate mineral with either hydroxyl radicals or fluorine, Al2SiO4(F,OH)2, used as a gem. It is commonly colorless or some shade of pale yellow to wine-yellow; pale bl...

gem, ornamental mineral or organic substance

(Encyclopedia)gem, commonly, a mineral or organic substance, cut and polished and used as an ornament. Gems also are used as seals (items of assurance) and as talismans (good-luck charms). For birthstones, see mont...

jewelry

(Encyclopedia)jewelry, personal adornments worn for ornament or utility, to show rank or wealth, or to follow superstitious custom or fashion. The most universal forms of jewelry are the necklace, bracelet, ring, p...

hail, in meteorology

(Encyclopedia)hail, precipitation in the form of pellets composed of ice or of ice and snow, occurring at any time of the year, usually during the passage of a cold front or during a thunderstorm. Small hailstones ...

earring

(Encyclopedia)earring, a personal adornment, sometimes an amulet, worn attached to the ear lobe. Since prehistoric times the ear has been pierced for the insertion of the earring; certain primitive tribes distort t...

cairn

(Encyclopedia)cairn, pile of stones, usually conical in shape, raised as a landmark or a memorial. In prehistoric times it was usually erected over a burial. A barrow is sometimes called a cairn. ...