as Radiators in Wireless lelegraphy. 691 



coils with their planes parallel to the earth's surface. These 

 observations are plotted in the curve shown in fig. 6. 



Fisr. 6. 



? 6 8 to 



freigfif of centre of cod in feet 



Exp. VI. The same measurement was made with the small 

 coils 2 feet square of 8 turns, placed at a distance of 60 feet. 

 The primary current was kept at 5*4 amperes. The receiver 

 was tuned to a frequency of 214,000 and the secondary 

 current was measured for various heights of the coils above 

 the ground, the coils being vertical and in positions (A.A.). 



Table VI. 



Height of centre of 



Coil above the ground, , 



in feet and inches. 



Secondary Current In 

 railli amperes. 



ft. ins. 

 1 



1 4 



1 8 



2 3 



3 2 

 5 3 

 7 2 



0166 

 0-460 

 452 

 0-515 

 0-570 

 0327 

 0-176 



