rK.IXS.lTLMXTlC R.iniO IT.I.F.rilOXn TR.IXS.UISSIOX 479 



riu- nirvi's of Fi^. 1() show also the substantial (litToroiirr in tlu' 

 noise li'Vfi whirli exists at the three receiving points. As has been 

 exix-riencx'il in practice, the New Southgate curve indicates that 

 Kngl.ind is less subject to interference tli.iti ikh llu-.i^icrii I'tiited 



hig. 16 — Frcquenry ilistrihution of noise, New Southgutc, Eng., Belfast, Maine 

 Riverhead, L. I. — Night time Day time Aug.-Dec, 1924 



States. In the I'nited States the superiority of Belfast over River- 

 head is also consistent with the better receiving results which in 

 general have Ijeen experienced in Maine. There should be noted also 

 the fact that the cur\es for these three locations lie one above the 

 other in the inverse order of the latitudes. This is in keeping with 

 other evidence which pf>ints towards the tropical belt as being a 

 general center of static disturbance on the longer wave lengths. 

 Further evidence on this point is presented below in connection with 

 the seasonal variations of noise. 



Seasonal Variation. Cur\es showing the diurnal \ariation in 

 noise level for each month of the year together with the \ariati(>n 



