Wireless Telegraphy and Telephony

WIRELESS TELEGRAPHY 133 By connecting a telephone transmitter to the arc in the same manner that it is connected to the speaking arc, the oscillations can be varied in accordance with the vibrations of the voice. The apparatus is' connected to the aerial and the earth through the medium of a loose-coupled helix, formed by providing the helix in series with the arc and condenser, with a secondary winding. Fig. 148—The Majorana wireless telephone transmitter. The ordinary carbon transmitter, in its common form, is unsuited for wireless telephonic work, on account of its inability to handle large amounts of power. Many modifi- cations have been designed, the usual procedure being to make it on a larger scale. ’ One of the most interesting forms, and also probably the best, is that devised by an Italian inventor, Majorana. Its action will be clear from the illustration. T is a tube in which water or some other liquid is allowed to flow in the direction of the arrow. 3 he bottom of the tube is contracted so that the stream will issue in a fine jet. The tube is made of strong, rigid material, except at one point, D, where an opening is covered with a thin elastic dia- phragm. This diaphragm is connected by means of a short