1908.] on Transatlantic Wireless Telegraphy. Ill 



The facility with which distances of over 100 miles could be 

 covered prior to 1900, and the success of the methods for preventing 

 mutual interferences,* led me to advise that two large power stations 

 be constructed, one in Cornwall and the other in North America, in 

 order to test whether it was possible to transmit messages across the 

 Atlantic Ocean. 



I have often been asked why I did not first endeavour to establish 

 commercial communication between places situated at a shorter dis- 

 tance. The answer is very simple. The cables which connect England 

 to the Continent, and between most Continental nations, are Govern- 

 ment-owned, and these Governments would not, and will not, allow 

 the establishment of any system, wireless or otherwise, which might 

 in any way tamper with the revenue derived from these cables. 



As regards transatlantic communication, however, the conditions 

 were different. There was no law either here, in Canada, or in the 

 United States, to impede the working of wireless telegraphy across 

 the Atlantic. 



A further potent reason, moreover, an economical reason, prompted 

 me to attempt communication with America. Notwithstanding the 

 cost of high-power stations, I am convinced that it is more profitable 

 to transmit messages at 0^^. a word to America than at, say, \d. a word 

 across the Channel, and that the economical advantage of wireless 

 over cables and land-lines increases instead of diminishing with the 

 distance. 



A site suitable for a long-distance station was chosen at Poldhu, 

 in Cornwall, and here in 1900 work w^as commenced in earnest — work 

 in which I was ably assisted by Professor J. A. Fleming, of the 

 University of London. 



The transmitter at Poldhu was similar in principle to the one 

 I have already described, but it is obvious that the considerable 

 distance over which it was proposed to transmit signals necessitated 

 the employment of more powerful electro-magnetic waves than those 

 ever previously used. 



These were obtained by means of a generating plant consisting of 

 an alternator capable of an output of about 25 kilowatts, which, 

 through suitable transformers, charged a condenser having a glass 

 dielectric of great strength. 



Time does not permit me to describe in detail all the engineering 

 difficulties which were encountered in controlling electrical oscilla- 

 tions of a power which at that time was certainly unprecedented, and 

 as the tests were made possible by commercial organisation, the 

 objects of which do not consist solely in the advancement of science, 

 you will understand that a detailed description of the plant used 

 at the transatlantic stations cannot, for the present at least, be 

 made public. 



* Journ. Soc. Arts, xlix. No. 2530, 1901. 



