rK.i.\s.iri..t.\iic R.inio TEi.nriiosii ikassmissios 47.» 



(if ilu- Atl.uilir wi- fiiuiid tli.it ,ipi>r<>\iin.itcl\ it .()().") .uul .v=I.'J."i. 

 rill- tr.insmissinii fnrimil.i tlu-ii biTomcs 



,, Mini .^n 



or ill terms t)f powi-r radiated 



298X10' MM) 

 E = \/p j-^ e- jrs 



wluTC 



/{ = Field strength in microvolts per meter 

 P = Radiated power in kw. 

 /? = Distance in km. 

 X = Wave length in km. 



The table sh;)\vn on next page summarizes the data relative to 

 da\light transmission. 



C"(iRKi:i.ATi()N Iii:r\vi;i;N Radio Tkansmission and I-.akhi's 

 Magnetic Kikld 



In anaKzing the measurements we were impressctl h> the occa- 

 sional occurrence of marked deviations from the apparent normal 

 diurnal characteristic. A series of measurements which includes an 

 example of this condition is represented in the upper curves of Fig. 12. 

 The curves of the first four days exhibit the normal diurnal char- 

 acteristic as did the curves of the preceding measurements. The 

 next test of February 25-26 exhibits a marked contrast with that 

 of two days pre\ious. Such abnormality continues in greater or less 

 degree until partial recovery in the test of April 29-30. 



C"omj)arison of these data with that of the earth's magnetic field 

 for corresponding days shows a rather consistent correlation. This 

 will Im? evident from inspection of the magnetic data plotted below 

 in the .siime figure. Both the horizontal and vertical components 

 of the earth's field are shown. The first decided abnormality- occurs 

 February 25-2(5. The three succeeding periods shf)w a tendency to 

 recover followed by a second abnormality on March 25 26 and again 

 one on .April 22-23. It is of interest to note that within limitations 

 of the intervals at which measurements were taken, these periods 

 correspond roughly to the 27-da>' period of the sun. Coincidences 

 similar to those described above ha\e been found for other periods. 

 Kxcept for this coincidence of abnormal variations in earth's magnetic 

 field and radio transmission, exact correlation of the fluctuations 

 has not been found possible. 



