RIO NEGRO 58 RIPLEY were published in 1867, and additions in 1872. He died in Madrid, Aug. 8, 1659. RIO NEGRO ("black river"), the name of numerous streams, of which two are important: (1) A river of South America, and principal tributary of the Amazon. It rises in Colombia, and joins the Amazon after a course of about 1,000 miles at Manaos, Brazil. Through its affluent, the Cassiquiari, there is di- rect communication between the Amazon and Orinoco. (2) A river of South America forming the boundary between the Argentine Republic and Patagonia. It rises in the Andes in Chile, and is about 700 miles long. Its current is very rapid, and its bed obstructed with shoals and sand-banks. RIOT, a disturbance of the public peace, attended with circumstances of tumults and commotion, as where an assembly destroys, or in any manner damages, seizes, or invades private or public property, or does any injury what- ever by actual or threatened violence to the persons of individuals. By the com- mon law a riot is an unlawful assembly of three or more persons which has act- ually begun to execute the common pur- pose for which it assembled by a breach of the peace, and to the terror of the public. A lawful assembly may become a riot if the persons assembled form and proceed to execute an unlawful purpose to the terror of the people, though they had not that purpose when they assem- bled. In England, every person con- victed of riot is liable to be sentenced to hard labor. In Scotch law rioting is termed mobbing. A person may be guilty of mobbing who directs or excites a mob though he is not actually present in it. Mere presence without participation may constitute mobbing. By an act of George I., called the Riot Act, whenever 12 or more persons are unlawfully as- sembled to the disturbance of the peace, it is the duty of the justices of the peace, and the sheriff and under-sheriff of the county, or of the mayor or other head officers of a city or town corporate, to command them by proclamation to disperse. And all persons who continue unlawfully together for one hour after the proclamation was made, commit a felony and are liable to penal servitude or imprisonment. Most, if not all, of the States of the American Union have riot acts some- what similar to those of England, and the common law governs where no stat- utes have been enacted. RIO TEODORO, or RIO THEODORO, also known as Rio Duvida, or River of Doubt, a river in Brazil, in the state of Matto Grosso, and rising in the Corde Leira dos Parecis. It is a tributary of the Rio Madeira, flowing northward be- tween long. 59° and 61° W. and nearly a thousand miles in length. Theodore Roosevelt partly explored it in 1914 and its name was changed in his honor. RIO TINTO, a river in southern Spain in the Province of Huelva, near whose sources are rich copper mines; the annual output (copper and sulphur) reaches 1,400,000 tons; these minerals are exported from the port of Huelva (q. v.), 45 miles distant, near the mouth of the river. These mines were worked by the Romans — their Tharsis. During the years of Moorish supremacy they were unused, but they have been worked again since the middle of the 18th cen- tury. They were bought in 1872 by the Rio Tinto (London-Bremen) Syndicate for $20,000,000. RIPLEY, GEORGE, an American author; born in Greenfield, Mass., Oct. 3, 1802; educated at Harvard University and Cambridge Divinity School; became a Unitarian minister in Boston; lived some years in Europe; was one of the founders of the Transcendental maga- zine, the "Dial" (on which he had Em- erson and Margaret Fuller as coadju- tors) ; and the originator and conductor of the communistic experiment at Brook Farm. He became literary editor of the New York "Tribune" in 1849, and was joint-editor with Charles A. Dana of the "American Cyclopaedia" (1858-1863, 16 vols., also of the second edition). He died in New York City, July 4, 1880. RIPLEY, WILLIAM ZEBINA, an American economist, born at Medford, Mass., in 1867. He was educated at the Massachusetts Institute of Technology and at Columbia University. From 1895 to 1901 he was a professor of economics at the Massachusetts Institute of Tech- nology, and in 1901 he became professor of political economy at Harvard Univer- sity. He lectured on sociology at Colum- bia University from 1893 to 1901 ; served as expert agent on transportation with the United States Industrial Commission, in 1900-1 ; and was the Huxley memorial lecturer at the Royal Anthropological In- stitute, London, England, in 1908. He was a member of numerous American and foreign scientific societies and twice vice-president of the American Economic Association. During the World War he served in the War Department as ad- ministrator of labor standards for army clothing, and in 1919 was chairman of the National Adjustment Commission of the United States Shipping Board. He published, besides many articles in peri-
