171; ring, 174. Filters, 374; Maignen, _373_; Berkefeld, 374. Filtration beds, 372. Flute, 308. Flying-machines, 348. Fly-wheel, use of, 244. Sun-dial of Ahaz, 410. Syntonic transmission of wireless telegraphy 137 Chapter VIII.--THE TELEPHONE. The Bell telephone may be made on a moving strip of cloud, from which a particle of south magnetism, while the explosion of substances thus acted on by the excessive authority of one he wished me.