Calcareous Tufa
a deposition from springs, streams, or underground water, from which it is precipitated partly by the escape of carbonic acid which acts as a solvent, and partly by evaporation of the water. It is usually white, creamy-white, yellowish, or brownish in color, but other hues occur, and variegated and mottled varieties are not uncommon. It is of variable texture kinds being and consistency; some rather soft, brittle, and friable, and porous or cellular. These cellular varieties have been deposited from the waters of springs, and often contain vegetable and animal remains, as leaves, twigs, nuts, moss, insects, land and fresh-water shells, etc. The so-called "petrifying springs" of Matlock afford a good example of the formation of calcareous tufa. In some regions the deposition from calcareous waters is on a very extensive scale, as along the river Anio, at Tivoli, near Rome, where calcareous tufa occurs in masses many feet in thickness. In that district the formation is harder and more compact, and under the name of travertino is used as a building stone at Rome. Calcareous tufa is abundantly deposited from thermal springs, as in the Yellowstone region of the United States. The calcareous incrustations so commonly seen in caverns in limestone rocks are varieties of calcareous tufa. They are known as stalactites and stalagmites.
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Calciferous Epoch
one of the subordinate divisions of the Lower Silurian System of North America. The division is characterized by the presence of calcareous sandstones and limestones. In Scotland a subdivision of the Carboniferous system is known as the Calciferous Sandstone group.
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Calcination
The process by which some bodies by the action of fire are reduced to the condition of a calx or cinder. Most of the metals can be reduced to this condition, which renders them easily reducible to powder. By subjecting ores to the action of the fire the volatile parts are driven off, and the water of crystallization dissipated. By this process marble is converted into lime by expelling the carbonic acid and water, and the same may be said of borax, gypsum, alum, and other saline substances which are deprived of their water of crystallization by the process of calcination. There is a difference between calcination and oxidation, fire being a necessary agent in the former case, while metals may be oxidated by acids, heat, or exposure to the atmosphere. See WEATHERING ORES; KILN. Calcium is a light yellow metal, somewhat harder than lead--very malleable; metals at a red heat and oxidizes in the air. It exists in abundance in limestone, fluor-spar, and gypsum. See LIME.
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Calcite
CALCAREOUS SPAR, or
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Calcium Carbide
chemical a compound of calcium and carbon, symbol CaC2. It is a hard, bluish-black, clear crystalline body, and is impervious to light, insoluble in all known solvents, and with a sp. gr. of 2.22. Although calcium carbide has been known for many years, it did not come into prominence until 1894, when Moissan produced it by heating 120 grains of oxide of calcium and 70 grains of sugar charcoal in an electric furnace. The furnace J was heated to 3,500° C. by an electrical current of 350 amperes and 70 volts for 20 minutes. This produced about 150 grains of carbide. Dry carbide is not affected by heat in an ordinary atmosphere, but when heated in an excess of oxygen it burns and forms calcium carbonate. When exposed to damp air for a short time it disintegrates and gives off a peculiar odor resembling garlic. When calcium carbide comes in contact with water, ACETYLENE GAS (q. v.) is produced and calcium hydroxide thrown down (CaC2+2H2O=C₂H₂+Ca (OH)2). It is used generally for the production of acetylene and the reduction of iron.
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Calcium Light
a brilliant light produced by directing the flame of an oxy-hydrogen blow-pipe against a block of compressed quicklime. It has been used on the stage for many years, and by the aid of colored glasses very charming effects are produced. More recently it was employed in lanterns for projecting photographic and biographic pictures on a screen. It has now been superseded by electric light.
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Caldecott
RANDOLPH, an English artist; born in Chester, England, artist: March 22, 1846. In 1882 he became a member of the Institute of Painters in Water-colors. He will chiefly be remembered by the admirable "Caldecott's Picture-books," which began in 1878, with "John Gilpin" and "The House that Jack Built." After vain attempts to restore his health by trips abroad, he died in St. Augustine, Fla., Feb. 12, 1886.
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Calder
WILLIAM M., an American senator, born in Brooklyn, N. Y., in 1869. He was elected in 1904 to represent the 6th New York district in the 59th Congress; was re-elected to the four succeeding Congresses. He was chosen delegate to the Republican National Conventions of 1908, 1912 and 1916. In 1916 he was elected United States Senator for the term beginning March 4, 1917.
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Calendar Clock
A clock which shows the progress of the calendar. In a simple calendar the mechanism has to be adjusted at the end of all months having less than thirty-one days. In a perpetual calendar the correct indications during short months and leap years are performed without adjustment.
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Calendula
a genus of plants, of which C. officinalis, the Garden Marigold, is a species. They are showy plants, and are in some places used in cookery.
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Caleton
HENRY GUY, an American journalist and dramatist, born in Fort Union, New Mexico, June 21, 1855. He pursued journalism in New Orleans and New York City, and has written several plays: "Memnon, a Tragedy"; and "The and "Victor Durand" (1884); Pembertons" (1890). He died Dec. 10, 1910.
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Calgary
a city in the Province of Alberta, Canada, with station on the Canadian Pacific Railway, 2,262 miles W. of Montreal. It stands 3,380 feet above sea-level, in a broad and level valley between the Bow and Elbow rivers, and is a trading center for a wide district, much of which is taken up by cattle ranches. It is the seat of the University of Calgary and of Mount Royal College (Methodist), and has numerous other educational institutions, churches, banks, etc. It is important as a milling center and its industrial establishments have greatly grown in recent years both in numbers and in importance, including now brickyards, cement mills, iron and metal works, packing houses, etc. Coal, lime, clay, and building stone are abundant in the vicinity. It dates from 1884. Pop. about 70,000.
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