112 



Commendatore G. Marconi 



[March 13, 



My early tests on wireless transmission by means of the elevated 

 capacity method had convinced me that when endeavouring to extend 

 the distance of communication it was of little utility merely to increase 

 the power of the electrical energy applied to the transmitting circuits, 

 but that it was also necessary to increase the area or height of the 

 transmitting and receiving elevated conductors. 



As it was economically impracticable to use verticable wires of 

 very great height, the only alternative was to increase their size or 

 capacity, which, in view of the facts I had first noticed in 1<S95, 

 seemed likely to make possible the efficient utilisation of large amounts 

 of electrical energy.* 



The form of aerial which I first proposed to employ consisted of 

 a conical arrangement of wires insulated at the top and gathered 

 together at a lower point in the form of a funnel. This aerial was 



FIG. 5 



supported by a ring of 20 masts eacli 200 feet higli, arranged in a 

 circle of 200 feet in diameter. 



During the first tests an arrangement of circuits (Fig. 5) pro- 

 posed by Dr. Fleming, and consisting of a modification of the system 

 shown in Fig. o, was employed. In this arrangement, in place of one 

 high-frequency oscillation circuit two are employed, and the constants 

 of the two circuits are so arranged that very high tension discharges 

 can be obtained from one of the condensers — the one which is induc- 

 tively connected with the aerial — without danger of damage to the 

 circuits of the generator.! 



Simultaneously with the construction of the station at Poldhu, 

 the erection of another one on substantially the same plan was under- 

 taken at Cape Cod in the United States of America. 



The completion of the arrangements was delayed owing to a storm 



* Journ. Inst. Elec. Eng. xxviii. 1899, pp. 278-9. 



t ' The Principles of Electric Wave Telegraphy,' 190G, p. 506, 



