204 WAVES OF SAND AND SNOW 



time already in the Bay of Biscay. At 8 a.m., 

 when I began observations, the wind had still a 

 force 9-25 of Beaufort's scale,^ and therefore a 

 velocity of 465 statute miles per hour. The sea was 

 running perfectly true; /.^., there were no cross- 

 ing waves, neither did I notice any waves longer 

 or shorter than the great billows which followed 

 one another in a procession of regular ridges . The 

 ship being hove -to on account of the violence of 

 the waves, I was able to measure their size and 

 speed with greater accuracy than usual. Their 

 height was approximately uniform, being rather 

 more than 3 i feet from trough to crest, their length 

 was 933 feet from crest to crest, and their speed 

 47 statute miles per hour. The wind maintained 

 its direction unaltered throughout the morning, but 

 by noon its velocity had decreased to 3 5- 5 statute 

 miles per hour. The waves by this time had 

 considerably diminished in height, length, and 

 speed. 



The course of events is clear. When the wind 

 came on to blow strongly it went into eddies having 

 long horizontal axes, on the lee side of the level - 

 crested ridges of the swells, which were the only 

 waves running. As long as the velocity of the 



' The numbers are the average of those given by different 

 officers observing at the same time. 



