CENTEBVILLE 404 CENTBAL FABE radius of gyration of the body about an axis through B parallel to the fixed axis, then it is easily shown that (h^+k^) AC= . h From this there follows the important proposition that the centers of oscillation and suspension are convertible, a propo- sition which was taken advantage of by Kater for the practical determination of the force of gravity at any station. CENTEBVILLE, a city of Iowa, the county-seat of Appanoose co. It is on the Chicago, Burlington, and Quincy, the Chicago, Rock Island, and Pacific, and the Southern Iowa Traction Company railroads. The city is an important live- stock center. There are also mines of coal, gypsum, and limestone. Other in- dustries are railway shops and manu- factures of lumber, flour, iron, etc. Pop. (1910) 6,936; (1920) 8,486. CENTIGBADE THEBMOMETEB, a thermometer scaled to represent the in- terval between the freezing and the boil- ing point of water, divided into 100 equal parts, the freezing-point being taken as zero, and the boiling-point as 100°. 1° C. is equal to 1.8° F. CENTIME. See Cent. CENTIPEDE, a genus of Myriopoda, having a long, slender, depressed body, protected by coriaceous plates, 21 pairs of legs, distinct eyes, 4 on each side, and antennae with 17 joints. The name is, however, popularly extended to species of nearly allied genera. Centipedes run nimbly, feed on insects, and pursue them into their lurking places. They have not only a pair of horny jaws, like those of insects, but also another pair of organs closely connected with the mouth, and which are regarded as transformed legs, dilated and united at the base, termi- nated by a strong hook, and pierced be- neath the extremity for the emission of a venomous fluid, which makes their bite quickly fatal to insects, and, in the case of the larger species, very painful, and even dangerous to the larger ani- mals and to man. CENTBAL AMEBICA, a geographical division, including the stretch of terri- tory from the Isthmus of Panama to the Isthmus of Tehuantepec, but by political arrangements the limits most generally assigned to it include the Republics of Guatemala, Honduras, San Salvador, Nicaragua, Costa Rica, and Panama, with British Honduras. It thus has Mexico on the N. W., Colombia on the S. E., and the Pacific Ocean and Carib- bean Sea on either side. Its entire length may be about 800 miles, with a breadth varying from between 20 and 30 to 350 miles. It is generally mountain- ous, contains a number of active vol- canoes, and on the whole is a rich and fertile, but almost totally undeveloped region. The area is about 220,000 square miles; the pop., about 5,500,000. CENTBAL FALLS, a town in Prov- idence CO., R. I., on the Blackstone river, and the New York, New Haven, and Hartford railroad, 4^ miles N. of Provi- dence. It has large manufactories of cotton, woolen, silk, and hair cloth goods, and of machinery and leather, for which the river supplies excellent power. There are several churches, newspapers, and banks. Pop. (1910) 22,754; (1920) 24,174. CENTBALIA, a city of Marion CO., 111., 60 miles E. of St. Louis and 252 miles S. W. of Chicago, on the Illinois Central, the Chicago, Burlington and Quincy, the Southern, and the Southern Illinois railroads. It is located in the orchard section of southern Illinois, and its fruit trade is large. There are manu- factories of iron, steel, envelopes, knit goods, flour, and butter, and the ma- chine works of the Illinois Central railroad. There are three banks, ten churches, high schools, and public schools, and a Carnegie library. Cen- tralia was settled in 1853 and became a city in the following year. Pop. (1910) 9,680; (1920) 12,491. CENTBALIA, a city of Lewis co., Wash., midway between Portland and Seattle. The chief industries are lum- ber, coal, and canned goods. The water- works and electric lighting plant are municipally owned. There are two banks, excellent schools and a Carnegie library. Centralia was first settled in 1857 and became a city in 1890. It is under a commission form of government. A tragedy that startled the nation occurred there on Nov. 11, 1919, during a parade of war veterans to celebrate the first anniversary of the signing of the armi- stice. Concealed members of the I. W. W. opened fire on the procession and sev- eral of the soldiers were killed. One of the assailants was killed in the fighting that followed, another was lynched, and others charged with committing the crime were arrested and held for trial. Pop. (1910) 7,311; (1920) 7,549. CENTBAL PARK, the most noted park in New York City. It contains 840 acres and extends from 59th street to 110th street, and from Fifth avenue to Eighth avenue. It was laid out by Messrs. Olmsted and Vaux, and contains
