1909] 



on Researches in Radiotelegrafhy . 



663 



ing such an oscillograph vacuum tube to the circuit of an inductively 

 coupled antenna, and examining in a revolving mirror the image of 



1800 



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1000 



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200 400 600 800 1000 1200 1400 1600 

 M Metres. 



Fig. 8. — Pierce's Experiments on Inductive Coupling. 



Fig. 9. — Oscillogram op Damped Oscillation (Antenna not connected 



TAKEN with THE GeHRCKE OSCILLOGRAPH VACUUM TUBE. 



the electrodes, they will be seen to present an appearance as in 

 Fig. 10, taken from photos^raphs kindly given me by Herr Hans Boas 

 Vol. XIX. (No. 103)^ 2 x 



