360; venous, 359. Blower-plate, 393, _394_. Boat, sails of, 346. Boiler, Babcock and Wilcox; Messrs. Siebe, Gorman, and Co.; The Micrometer Engineering Co.; Messrs. Marshall and Sons; The Maignen Filter Co.; Messrs. Broadwood and Co. [Illustration: ON THE FOOTPLATE OF A TELEPHONE EXCHANGE.] DOUBLE-LINE CIRCUITS. The currents used in large clocks, such.