42 REPORTS ON THE STATE OP SCIENCE.— 1919. 



The most striking results were obtained at some of the stations in 

 France, Malta, and Teneriffe. At Meudon and at Eoussillon the signals 

 from Ascension were received practically only while the eclipse was in 

 progress. Both Malta and Teneriffe found that the eclipse produced a 

 great improvement in the strength of signals. On the other hand, 

 Durban was unable to pick up Cairo, though this is usually possible, 

 but Aden was picked up with greater intensity than normal. On the 

 whole, the records show that the improvement in signal strength 

 reached its highest value long before the umbra intervened between 

 the stations, and this value persisted after the umbra had passed; that 

 is to say, if ionising processes are the cause of the change in the 

 strength of signals, the results indicate that the processes are prac- 

 tically fully accomplished in a given region of the air before the a^Tival 

 of the umbra at that place, so that there appears to be nothing left for 

 the umbra to do in the few minutes of complete shadow it brings. 



The thanks of the Committee are due especially to the Admiralty 

 for arranging that their stations at Ascension and the Azores should 

 transmit the necessary signals, and also to the American Government 

 for making similar arrangements i-egarding Sayville and Darien. 

 Thanks are due also to the American, French, and Itahan Govern- 

 ments, the Admiralty, the War Office, the Air Ministry, and Marconi's 

 Wireless Telegi-aph Co., Ltd., for undertaking observations and record- 

 ing the variations in signal sti'ength. 



