a city and the county-seat of Pickaway county, Ohio, U.S.A., about 26 m. S. by E. of Columbus, on the Scioto river and the Ohio Canal. Pop. (1890) 6556; (1900) 6991, of whom 551 were negroes. It is served by the Cincinnati & Muskingum Valley (Pennsylvania lines) and the Norfolk & Western railways, and by the Scioto Valley electric line. Circleville is situated in a farming region, and its leading industries are the manufacture of straw boards and agricultural imple 1 On the calculations made before Shanks, see Lehmann, "Beitrag zur Berechnung der Zahl 7r," in Grunert's Archiv, xxi. 121-174.
See Montucla, Hist. des rech. sur la quad. du cercle (Paris, 1754, 2nd ed. 1831); de Morgan, Budget of Paradoxes (London, 1872).
"Sur la fonction exponentielle," Comptes rendus (Paris), lxxvii. 18, 74, 226, 285.
4 See Crelle's Journal, lxxvi. 342.
s See "Uber die Zahl 7r," in Math. Ann. xx. 213.
ments, and the canning of sweet corn and other produce. The city occupies the site of prehistoric earth-works, from one of which, built in the form of a circle, it derived its name. Circleville, first settled about 1806, was chosen as the county-seat in 1810. The court-house was built in the form of an octagon at the cen t re of the circle, and circular streets were laid out around it; but this arrangement proved to be inconvenient, the court-house was destroyed by fire in 1841, and at present no trace of the ancient landmarks remains. Circleville was incorporated as a village in 1814, and was chartered as a city in 1853.