&Q Dr. J. W. Nicholson on the Bending of 



Table II. 



e. 



n° 



12° 

 13° 

 14° 

 15° 

 16° 

 17° 

 18° 

 19° 

 20° 



Amp. ratio. 



•0047 

 •0030 

 •0020 

 •0013 

 •0 3 81 

 •0 3 52 

 •0 3 32 

 ■0 3 20 

 •0 3 13 

 •0*78 



Terrestrial 



miles. 



759 



828 



897 



966 



1035 



1104 



1173 



1242 



1311 



1380 



0. 



Amp. ratio. 



21° 



•0 4 48 



22° 



.0*30 



23° 



•0 18 



24° 



■0*11 



25° 



•0 3 68 



26° 



•0 5 42 



27° 



•0 5 25 



28° 



•0 5 15 



29° 



•0 6 93 



30° 



•0 6 56 



Terrestrial 

 miles. 



1449 

 1518 

 1587 

 1656 

 1725 

 1794 

 1863 

 1932 

 2001 

 2070 



Table III. 



e. 



Amp. ratio. 



Terrestrial 

 miles. 



e. 



Amp. ratio. 



Terrestrial 

 miles. 



35° 



•0 T 44 



2415 



65° 



•0i 4 66 



4485 



40° 



•0 8 34 



2760 



70° 



•0 15 46 



4830 



45° 



•0 9 25 



3105 



75° 



•0 16 32 



5175 



50° 



•0 10 18 



3450 



80° 



7 22 



5520 



55° 



•0 U 13 



3795 



85° 



•0 l8 15 



5865 



60° 



•0 13 94 



4140 



90° 



•0 l9 10 



6210 



These tables are in the form which indicates most readily 

 the amount of shadowing due to the earth at any point of 

 its surface, without confusion with the ordinary fall of in- 

 tensity due to distance from the oscillator. The shadowing 

 soon becomes very complete, for the ratio of the mean 

 energies per unit volume in the two cases is given by the 

 square of the amplitude ratio. 



But in estimating the capacity of diffraction for giving an 

 explanation of the great success of experimenters, other 

 tables are required, for the degree of sensitiveness possible 

 to the receiver plays a determining part. Let us suppose 

 that a given receiver will function at a distance of about 

 seventy miles or one degree from the oscillator. Tben the 

 further degree of sensitiveness necessary, in order that it 

 shall detect radiation at an orientation 0, may be found by 

 comparing the two cases 6 = 0° and 0=1°, without reference 



