HOMOGENEOUS BEAMS 159 



n* t^t^t-t^-t^l 



O5 1-1 CO * O O 

 O CO X O5 O -! (N 



,_, ,_, ,_, ,-1 frj W N .H <N <N <N CO CO CO * * 



<}< C * 00 O 01 CO 

 I>O5O'-"CO'*O 



' ,_i ,H' rH ^i r-i ' ' ^i i-i ,H r-i r-t rH rH r-J ^H (N (N N (N (N CO CO CO 



^, ^ ^ C^J (M (N JO rHrt 



Tft O <O t^ 00 O3 O * 



xxxxxxx xxxxxxxxx xxxxxxxxxx 



co co co eo eo co co g$gg$$g$$ nnnnnnnl 



