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When an electrical spark was made in the air, the electrical 

 effect was propagated in all directions, — it was practically 

 making a splash in the ether, as a stone makes a splash in 

 water, and sends out concentric circles radiating from the splash. 

 The connection of this fact with the amazing phenomena of 

 " wireless " telegraphy is, as he very clearly explained, imme- 

 diate and all-important. One of the principal facts which the 

 clever young Italian, Marconi, was the outcome of the researches 

 of the German doctor Herz. It was found that if an electric 

 circuit, part of which was enclosed in a glass tube, were in- 

 terrupted in a special manner by a small space within the tube, 

 the current would over-leap that space, and continue its action, 

 while if this space were occupied by fine metal filings, the 

 current was stopped. If, however, the ether waves from an 

 electric spark fell upon this tube, the filings would become 

 arranged, and, in some mysterious way that is not yet under- 

 stood, the current would be re-established. Here was the secret 

 of wireless telegraphy. For if this " coherer," as the tube 

 with the filings was called, was connected with a bell battery 

 so that when the current was established the bell would 

 ring, and vice-versa, a method of signalling was at once 

 established. By making electric sparks of long or short 

 duration send their waves upon the coherer, long or 

 short rings would be produced, which could be interpreted, 

 as a sound alphabet, by the Morse code. In practice it was 

 found that unless the battery creating the sparks were close to 

 the coherer, a couple of long metal rods attached to the ends of 

 the latter were absolutely essential, their efiect being to seize a 

 greater length of the electric wave, in a way comparable to that 

 in which an ear trumpet gathers a greater length of sound waves 

 for a deaf person. It was this discovery of the efiect of the rods 

 in rendering the receipt of signals possible at a distance that was 

 Marconi's peculiar contribution to " wireless " telegraphy. Dr. 

 Fleming had got a coherer and rods, and a battery upon the 

 platform. He made a spark at one end, and the bell attached to 

 the coherer instantly rang from no visible cause in the wierdest 

 way. A smaller coherer was carried by the Lecturer's assistant 

 all round the room, and the bell was rung by the waves sent out 

 from sparks of the battery on the platform. It would make 

 no dift'erence, said Dr. Fleming, if they carried the coherer 

 out into the Pavilion grounds, for "stone walls do not a 

 prison make " for the ether waves. By means of high masts, 

 with wires running from a cross piece at the top to the earth 

 Signor Marconi had succeeded in sending a telegraphic message 

 34 miles through empty air. It was not really " wireless" tele- 

 graphy, for these wires on the masts were necessary, and the 

 longer the perpendicular length of wire, the further could the 



