THEORETICAL EFFECTS OF PRESSURE WAVES. 



223 



e= 90° 



(a) (b) 



Fig. 67. Modified pressure distribution. = 90°. 



e = 90°, figure 67. — The wave has travelled on an eighth of its length, but the change 

 in pressure has not been sufficient to affect nxaterially the pressure distribution. The wind 

 is still northerly at Cape Evans, but has become south-easterly at Framheim. 



