ELECTRIC WAVES, a motion or dis turbance of the ether or medium in which elec tricity manifests itself and appears to move, of a character similar to light waves, of varying length, according to the nature of the dis charge but with a velocity similar to that of light. The wave theory was early held by Clerk Maxwell, Lord Kelvin and others, but was first demonstrated by Heinrich Rudolph Hertz (q.v.), who began experimenting about 1883. He discovered that electric waves would produce a slight sparking between metals when very nearly in contact. About 1::7 he ex hibited a special form of condenser, which he termed a radiator, but which would now be called an oscillator, as it discharges across a spark gap with oscillations. In connection with this he employed what he termed a resonator, but which would now be styled a wave-detec tor. By radiating electricity at different oscil lations and detecting the waves at certain har monious distances, while demonstrating their non-appearance at intermediate points, Hertz proved, the theory of wave action and that electricity travels in the same way as light, and paved the way for the later invention of wire less transmission. Hertz also reflected and re
fracted and polarized the waves, thoroughly demonstrating their action under the same laws as light waves. For a time the waves were referred to as Hertzian waves in honor of his contribution to science. The study of the waves was at once taken up by numerous students of electrical phenomena, and Lodge, Kelvin, Poln care and others made investigations which in creased knowledge of the subject. Bose de signed an instrument for producing very short electrical waves so they should be more easily studied. Later Brady of Paris devised an im proved form of detector, and E. Rutherford brought out a magnetic detector. These were outclassed later by William Marconi's coherer, and that has yielded place to still more accurate i detectors now used in radiography. See TELE GRAPHY, WIRELESS.