CIRCE 507 GIRCtTLATION cassian stock remain. The Circassians, properly so called, have been estimated variously to number from 150,000 to 500,000. CIRCE (ser'se), a daughter of Sol and Perse, celebrated for her skill in magic and poisonous herbs. She mar- ried a Sarmatian prince of Colchis, whom she murdered to obtain the king- dom, but was expelled by her subjects, and carried, by her father, to an island called ^a, on the coast of Italy. Ulysses, on his return from the Trojan war, visited her coast ; and all his companions, who ran headlong into pleasure and voluptuousness, were changed by Circe's potions into swine. Ulysses, fortified against all enchantments by an herb called Tnoly, which he had received from Mercury, demanded from Circe the restoration of his companions to their former state. She complied, loading the hero with honors; and, for one whole year, he forgot his glory in his devotion to pleasure. CIRCLE, a plane figure contained by one line, which is called the circumfer- ence, and is such that all straight lines drawn from a certain point (the center) within the figure to the circumference are equal to one another. The proper- ties of the circle are investigated in books on geometry and trigonometry. Properly the curve belongs to the class of conic sections, and is a curve of the second order. A great circle of a sphere is one that has its center coinciding with that of the sphere. The celebrated prob- lem of "squaring the circle" is to find a square whose area shall be equal to the area of any given circle. It is not possible to do so. All that can be done is to express approximately the ratio of the length of the circumference of the circle to the diameter, and to deduce the area of the figure from this approxima- tion. If the diameter be called unity, the length of the circumference of the circle is 3.1415926535....; and the area of the circle is found by multiplying this num- ber by the square of the radius. Thus the area of a circle of 2 feet radius is 3.14159x4, or 12.56636 square feet ap- proximately. For trigonometrical cal- culations the circumference of the circle is divided into 360 equal parts called de- grees, each degree is divided into 60 min- utes, and each minute into 60 seconds. CIRCLEVILLE, a city and county- seat of Pickaway co., O. ; on the Scioto river, the Ohio and Erie canal, and the Cincinnati and Muskingum Valley and the Norfolk and Western railroads, 28 miles S. of Columbus. It derives its name from a circular earth work built by some ancient people, which is the site of the present city. It has strawboard works, canneries, and flour mills, numer- ous churches, a high school, graded pub- lic schools, several daily and weekly newspapers, 3 National banks, etc. Pop (1910) 6,744; (1920) 7,049. CIRCUIT COURT, a court in the United States next in rank to the United States Supreme Court. In 1920 there were nine circuits, each consisting of sev- eral States, and each is allotted to one of the nine justices of the Supreme Court, who must attend at least one term of court in each district of his circuit every two years. Courts may be held at the same time in different districts of the same circuit. These courts formerly had original jurisdiction, concurrently with those of the States, in civil suits in law or equity for more than $500 between citizens of different States, or where an alien is a party or the United States plaintiff, as well as in revenue cases and some in bankruptcy, and in some crim- inal cases concerning persons denied citi- zenship under State laws, or offenses against the United States. Their appel- late jurisdiction extended to admiralty and maritime cases, to civil actions re- ferred from the district courts, to patent cases, and some others. Since 1911 these courts, by an act of Congi'ess, have only an appellate jurisdiction. The judges of each circuit and the justices of the Su- preme Court for the circuit constitute a Circuit Court of Appeals. The First Cir- cuit consists of Maine, Massachusetts, New Hampshire, Rhode Island, Porto Rico. Second — Connecticut, New York, Vermont. Third — Delaware, New Jersey, Pennsylvania. Fourth — Maryland, North Carolina, South Carolina, Virginia, West Virginia. Fifth — Alabama, Florida, Geor- gia, Louisiana, Mississippi, Texas, Canal Zone. Sixth — Kentucky, Michigan, Ohio Tennessee. Seventh — Illinois, Indiana, Wisconsin. Eighth — Arkansas, Colorado, Oklahoma, Iowa, Kansas, Minnesota, Missouri, Nebraska, New Mexico, North Dakota, South Dakota, Utah. Wyoming. Ninth — Alaska, Arizona, Californi?, Ha- waii, Idaho, Montana, Nevada, Oregon, Washington. CIRCULAR NOTES. See Crepit, Letter of. CIRCULAR NUMBERS, numbers whose powers end on the same fign^"'e as they do themselves: such are numbers ending in 0, 1, 5, 6. CIRCULATING LIBRARY. See Library. CIRCULATION, in anatomy and physics, th«? term used to designate the
