The name "Wireless Telegraphy," however, is specifically applied to a system of signaling by means of ether-waves induced by electrical discharges of very high voltage. Ether-waves of a greater or less degree are always set up whenever there are sudden electrical disturbances, however slight. Ether-waves, electrically induced, are probably as old as the universe. When "there were thunders and lightnings" from the cloud that hovered over Mount Sinai in the time of Moses, ether-waves of great power were sent out through the camp of Israel. But the people of those days had no "coherer" or telephone or any other means of converting these waves into visual or audible signals. Thousands of years had to elapse before the intellect of man could grasp the meaning of these natural phenomena sufficiently to harness them and make them subservient to his will. Many people have been powerfully "shocked"--some even killed--by the impact of ether-waves set up by powerful discharges of lightning between the clouds and the earth--when they were not in the direct path of the lightning-stroke. The history of Electro-Wireless Telegraphy, like that of all inventions, is one of successive stages, and all the work was not done by one man. The one who gets the most credit is usually the one who puts on the finishing touches and brings it out before the public. He may have done much toward its development or he may have done but little. In the year 1842 Morse transmitted a battery current through the water of a canal eighty feet wide so as to affect a galvanometer on the opposite side from the battery. This was wireless telegraphy by _conduction_ through water. In 1835 Joseph Henry produced an effect on a galvanometer by ether-waves through a distance of twenty feet by an arrangement of batteries and circuits like that shown in Fig. 1, Chapter VI. This was called _induction_, and is still so called when electrical effects are produced from one wire to another through the ether for short distances. All induction-coils and transformers (see Chapter XXIV) are operated by effects produced through the ether from the primary to the secondary coil--but through very short distances.