







1 / ^^^ ' 













/§&s^ 1^-—--'"' 



RELATION BETWEEN / //°Jf^ 





WAVE VELOCITY, 



//y^ 







PERIOD, AND j^/V 



^ 0.6^- — ^""^ 







DE 



:pth 



l//v jr 



///As 



0.5' 











1/ 



/^ 





0.4' 

 0.3'. 



0.2' 











/ 







0.1' 







■Sy 



<o/ 



" / 



0/ 

















0.2 



0.4 



0.6 



0.8 

 T- SEC. 



PLATE 4 



1.0 



1.2 



1.4 



1.6 



