22 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



which would carry it from pole to Equator in one period of oscilla- 

 tion. This is evidently a law which applies to wavelike changes of 

 all lengths. 



Fig. 14. — Wave front showing speed of movement in a 7-day vi^ave. 



In Dr. Weickmann's ' able analysis of the 24-day wave of pres- 

 sure of the winter of 1923-24, it is shown that the wave originated 



^ Petermanns Mitteilungen, Erganzungsheft No. 191, 1927. 



