20 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



Alaska, southeastward to Key West, Florida, and to Colon, Panama. 

 It is evident from the plot that the maxima and minima occur later 

 at southern stations, so that at'Williston, North Dakota (not shown 

 in fig. 12), the oscillations are opposite in phase to those at Nome; 



Fig. 13. — 14-day pressure wave. 



hut further southward at Key West they are in the same phase as 

 at Nome, although much diminished in intensity. 



Figure 13 shows an oscillation of 13.6 days averaged in overlap- 

 ping two-period intervals. The continuous lines were plotted from 



