VARIETY m TIDES — MAHMEB 



183 



effects of wind or weather. Heavy winds and rapid variations in 

 barometric pressure do bring about very marked changes in the 

 rise and fall of the tide. But the last 4 days of May 1931 were pur- 

 posely chosen because weather conditions then were relatively uni- 

 form. The features exhibited by the tides shown in figure 1 are 

 characteristic features of the tide at the three places. 



Figure 2. — Tide curves, Seattle, Honolulu, and San Diego, May 28-31, 1931. 



If we go to other places we find yet other varieties of tides. In 

 figure 2 are shown the actual records of the tide for the same 4 

 days of May 1931 at Seattle, Wash., Honolulu, Hawaii, and San 

 Diego, Calif. At each of these places it is seen that there are 2 

 high and 2 low waters in a day. At Seattle, however, morning and 

 afternoon high waters do not differ much, while the morning and 

 afternoon low waters differ strikingly. On the last day shown in 

 fiffure 2 the afternoon low water was 10.5 feet higher than the 



