ARNOLD, BION JOSEPH (1861— ), American elec trical engineer, was born at Casanovia, near Grand Rapids, Mich., on Aug. 14, 1861. He studied at the University of Nebraska in 1879-80, graduated from Hillsdale college, Hillsdale, Mich., in 1884, and did graduate work at Cornell university in 1888-89. Establishing himself in Chicago as an independent consulting engi neer in 1893, and later in the Arnold Engineering Company, of which he was president, he became widely known as an expert on electric traction. Important undertakings in which he was en gaged as chief engineer or authoritative adviser include the electri fication of the New York Central Railroad's terminal in New York city, the construction of subways in New York and Chicago, and the rebuilding of the Chicago street railway system. He also acted at various times as advisory engineer on traction problems for Pittsburgh, San Francisco, Los Angeles, Cincinnati, Toronto and many other cities. During the World War he was a member of army and navy consulting boards and in 1917-19 served in the regular army in various engineering activities, especially in connection with aircraft production. He invented a magnetic clutch, various storage battery improvements and numerous devices and systems for electric railway operation, and was one of the first to make use of alternating current and single-phase electric traction systems.