ISOSEISMALS: DISTRIBUTION OF APPARENT INTENSITY. ool 
respect to the car increased from the bottom to the top. That the whole upper surface of 
sand in the car did not move together with the same speed was quite plain to direct 
observation. When the sand was very soft and wet, it rose and fell near the ends in the 
form of incipient waves, which, however, were not propagated away from the ends, three- 
6 a 
oe Sonat Wet gravel 
wy ee = Te QOLDry gravel 
So] ere 0 Ot car 
3 Tie 
D © 9° nN N 
fi | Pall 
oat 7wo /a yers 
wet ‘underneath 
N Car 
BA AGA Lue 
= 
N 
Amplitude of oselilation in centimeters 
d ® n 4h 
e ca tee 
\ $ 

Fig. 62.— Graphic representation of results. 
