240 THE' NEW WORLD OF SCIENCE 



to a single degree of arc. If the station is feeble, and far away, 

 he may not be able to tell the exact direction to perhaps 20 

 degrees. His observations do not tell him the distance of the 

 station whose direction he assigns, except as he may guess the 

 distance from the strength of the received signals. But if there 

 are two, or still better, three such houses equipped with radio 

 goniometers, and their positions are properly marked on the 

 map; then if they take simultaneous cross bearings of the same 

 sending radio station, the signals from which are tuned to by 

 all, these cross bearings will locate that sending station definitely 

 on the map. 



The Allied armies in Europe maintained a coordinated series 

 of goniostations at some kilometers distance behind the fighting 

 line and at intervals of about 15 kilometers along it. Radio 

 watch was kept in these stations, day and night, by skilled 

 observers, who thus patrolled the ether. Some of them directed 

 special attention to giving notice of the approach and direction 

 of hostile airplanes having radio equipment. Others listened 

 for radio messages from one hostile ground station to another 

 on the enemy's side of the line, striving to record both the 

 message and the direction of the station whence it came. 

 Again, others listened for and responded to orders from Allied 

 radio officers in charge. Each goniostation took up its assigned 

 duties in this coordinated patrol work. A regular code of radio 

 procedure was planned and executed, whereby all observers 

 regularly watched and recorded ; but emitted radio signals only 

 on order. The ordinary reports from each goniostation were 

 transmitted by wire, at regular intervals, to the intelligence 

 department of the general staff, and emergency reports upon 

 the instant. By dovetailing simultaneous directions and bear- 

 ings from adjacent goniostations, headquarters was able to plot 

 the positions of enemy radio stations at various distances behind 

 the opposing lines, to decipher the enemy's code messages, and 

 to keep statistics of his radio traffic. The imminence of a 

 threatened attack from the enemy could be predicted often days 

 in advance, by studying this collected material. These col- 



