LONG-WAVE RADIO TELEPHONE TRANSMISSION 697 



For values of u from 0.0 to 0.6, Mi = 1007^ — 30. 

 For higher values/" 



0.6 to 1.6, wi = 30 + 100(u - 0.6) - 30(u - 0.6)% 

 1.6 to 3.6, Ml - 100 + 40(z^ - 1.6) - \0{u - 1.6)-, 

 3.6 to 00, Wi = 140, 



Wi increases less rapidly, approaching asymptotically the limiting value 

 140. The quantity Ui has been introduced in order to obtain a measure 

 of activity which has a frequency-distribution similar to that of the 

 relative sunspot-numbers, and therefore is more suitable for research on 

 correlations between terrestrial-magnetic activity and solar activity." '■^'* 



APPENDIX II 



Data for East-West transmission were combined with data for 

 West-East transmission for two illustrations, Figs. 4 and 5, given in 

 this paper. Two unpublished studies by the authors of this paper 

 showed that the correlation between transmission from Rugby to 

 Houlton on 68 kilocycles and transmission from Rocky Point to Cupar 

 on 60 kilocycles was very high, 0.80 ± 0.01. The scatter diagrams 

 for these studies were so similar that only one is shown here. Fig. 9. 

 For transmission on 60 kilocycles in both directions the correlation was 

 0.76 ± 0.02. These results are considered sufficient justification for 

 combining East-West and West-East radio transmission data to 

 obtain average curves. 



