1908.] 



on Transatlantic Wireless Telegraphy. 



125 



By means of this apparatus, tests were carried out, but it was 

 found, as was to be expected, that the oscillations were too continuous 

 and of too high a frequency to affect a receiver, such as the magnetic 

 detector, unless an interrupter was inserted in one of the circuits of 

 the receiver. A syntonic coherer receiver would, however, work, in 

 consequence no doubt of the considerable rise of potential which 

 occurred at its terminals through the cumulative effect of resonance. 



The best results over long distances have, however, been obtained 

 by a disc as shown in Fig. 14, in which the active surface is not 

 smooth, but consists of a number of knobs or pegs, at the end of 

 which the discharges take place at regular intervals. In this case, of 



FIC.14. 



course, the oscillations are not continuous, but consist of a regular 

 succession of trains of undamped or slightly damped waves. 



In that manner it is possible to cause the groups of oscillations 

 radiated to reproduce a musical note in the receiver, distinguishable 

 in a telephone, and thereby it is easier to differentiate between the 

 signals emanating from the transmitting station and noises caused by 

 atmospheric electrical disturbances. By this method very efficient re- 

 sonance can moreover be obtained in appropriately designed receivers. 



A few tests with apparatus based on the principle described were 

 carried out between Glace Bay and Clifden, and on October 17 of 

 last year a limited service for press messages was commenced between 

 Great Britain and America. Difficulties were experienced, however, 



