140 



RECENT ADVANCES IN WIRELESS TELEGRAPHY. 



tion in the distances over which it is possible to communicate; this 

 result being due, no doubt, to the much greater length of wave radi- 

 ated by the big elevated conductor of the long-distance stations, 

 compared with the shorter wave-length radiated by the smaller and 

 less powerful installations. Thus messages were received from Polclhu 

 at the positions marked on the map (fig. 13), which is a copy of the 

 map accompanying the official report of the experiments. These posi- 

 tions, at which signals were received direct from Poldhu, are in the 

 Baltic near Sweden, at Kiel, the North Sea, the Bay of Biscay, also 

 Ferrol, Cadiz, Gibraltar, Sardinia, and Spezia. Messages were re- 

 ceived distinctly in these places from Cornwall, although, in the Baltic, 



TRACK OF 

 R.N. CARLO 

 ALBERTO 



Naples to Kromtait 



Kronstadt to Spezia 



Fl«. Va 



the whole of England, the Netherlands, and part of Germany and 

 Scandinavia lay between Poldhu and the Carlo Alberto. Also, at 

 Cadiz and Gibraltar the whole of Spain intervened ; and at Spezia and 

 Cagliari, in the Mediterranean, the whole of France, including the 

 Alps, lay in a direct line between the two stations. 



After these ex^Deriments the Ca7'lo Alberto was sent back from the 

 Mediterranean to Plymouth, and thence conveyed the author to Can- 

 ada ; and in October, 1902, signals from Poldhu were received on 

 board ship throughout the voyage up to a distance of 2,300 miles. 



In December, 1902, messages were exchanged between the stations 

 at Poldhu and Cape Breton, but it was found that communication 

 was better from Canada to England than in the opposite direction. 



