CAR-BUILDING
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CARDIFF
Enormous quantities of it are poured into the air by the breathing of animals and the burning of fuel, but plants absorb it by their leaves to get carbon for the formation of wood, and in this way the proportion is kept quite constant. Carbonic acid contains by weight 12 parts of carbon and ?2 of oxygen. It is a dense gas, heavier than air, and can be poured from one vessel to another like a liquid. In vats in which it is being given off by fermentation, it remains at the bottom for some time, even when freely exposed to the air, so that fatal accidents have resulted from workmen carelessly entering them. Under a pressure of about 600 pounds to the square inch it becomes a liquid. When this liquid is allowed to escape through a small jet, it rapidly evaporates and causes intense cold, so that a certain portion becomes frozen into a solid resembling snow. This solid passes back into a gas without becoming a liquid. Carbonic acid can be easily dissolved in water. The sparkling appearance of soda and seltzer waters, etc. is produced by the carbonic acid which has been dissolved under pressure, and so passes out when exposed to the air. Champagne and fermented ginger beer contain carbonic acid by a natural process of fermentation. The pure gas, or air containing considerable quantities of it, causes suffocation when breathed, because the lungs do not get the necessary oxygen. It does not support burning. If a lighted taper is thrust into a vessel of it, it is immediately put out. Carbonic acid may be readily prepared from chips of marble and hydrochloric acid.
Car = Building. While the term car strictly means any wheeled vehicle, in America it has been applied only to railway cars, in the first instance, but has been extended recently to automobiles or motor-cars. Automobile building will receive separate treatment. The most distinctive feature of the car is the truck, which consists of a frame, one at each end of the car, with two, four, six or even eight wheels underneath, and on the top a swivel, on which the car-body rests, so that it can move freely on the trucks under all the varying conditions of the road. The wheels are of many kinds, agreeing, however, in rejecting the spoke and axle arrangement which most wheels have. Moreover, the wheels do not turn on the axle, but are fixed firmly upon it, by shrinking or other means, and the axle turns in the axle box. The wheels have flanges to keep them on the rails. The car rests on two sets of springs, one vertical, which supports a frame, from which the other, an elliptical spring, is suspended. The car rests immediately on the latter. The car-body is of many types. The finest is the Pullman car. This was first built about 1867 by George Mortimer Pullman; they are for
the most part built at the Pullman works near Chicago. The latest modifications are cars in which the berths are put under the floor, when not in use, and the car itself turned into a parlor-car. The pressed-steel car is built at Pittsburg; in it every part of the car is built of steel. Pullman cars commonly have a steel framework which embraces the platform, so as to form what is called a solid vestibule-train. Their strength has saved many lives in our numerous accidents. American cars differ from those of other countries in their greater size and in having the aisle run up the middle of the car. Among freight-cars the most noteworthy are the refrigerator-cars, which are largely built and owned by private companies, such as the Armour Company and the Swift Refrigerator Company of Chicago. Special cars are used to carry enormous loads of coal from the mountains of Pennsylvania to the coast cities. The Standard Oil has built special tank-cars for its oil. Most of the regular freight and passenger-cars are now built at the shops of the several railroad companies. There are special features, such as automatic couplers, now compulsory on all cars, air-brakes, gas-lighting and heating from the steam of the engine. In most countries of Europe they still employ foot-warmers which can be filled with hot water at certain stations.
Cardenas (kdr'da-nas), Cuba, a seaport in the province of Matanzas, situated on the north side of the island, 78 miles east of Havana, with which it is connected by rail, as well as with Santa Clara, Cien-fuegos and Matanzas. It is the chief port for the export of sugar, and has besides a considerable local commercial trade. It is an attractive city, with many fine plazas and public buildings. In our war with Spain, Cardenas Bay was the scene of a sharp engagement between our blockading vessels and the :; Spanish batteries, in which the first American officer to lose his life in the war (Ensign Worth Bagley) was killed. Population, 28,576.
Car'diff, a seaport town in southern Wales, on Bristol Channel. It is noted for its magnificent docks, from which several millions of tons of iron and coal are exported yearly. Cardiff is well known in history. The Arthurian legend of the sparrow-hawk refers to Cardiff. King Henry I imprisoned, for 26 years, until his death, his brother, Duke Robert, in the old castle, which still stands. The castle was once of enormous strength, and is now the mansion of the Bute family, to whom the present prosperity of Cardiff is largely due. At Cardiff there is a branch of the University of Wales, with a teaching staff of 55 and with 661 students. Population, 182,280,
