TK.ixs.ii I..IMIC A'.//)/() ii:i.i:i'ii(>.\i: i r.ixsmissiox .w 



- {ITmi I fW\ 1 1 'T!"; ! 1 1 '^^ 1 1 ! !Th 1 1 !?f ' j 1 1 tlTi ! 1 1 rf^^'' I p'''^| [^'^ • I jT'H'f I fl^i t'° 



Mimllilv .\vir.i>;r of Diurnal X'ariation of Noise 

 Belfast, Maim- 52,000 Cycles 



1924 



secruoen ocnxtR Novc««efl acnen 



Monlhlv Average of Diurnal Variation of Noise 

 Riverhead, L. I. 15,000 Cycles 



1924 



