26 WAVES OF THE SEA 



on smaller sheets of water. In a rock pool, 20 feet 

 in diameter, under High Peak, Sidmouth, Devon, 

 I have measured waves of i inch wave-length at the 

 windward end, and 4 inches at the leeward end, 

 the wind having the force of a gale. Thus if we 

 take the average length of the waves to be 2 J inches, 

 there was in this small pool a series of ninety 

 consecutive waves, the longest of which was i-6oth 

 of the length of the series. 



On the Round Pond in Kensington Gardens, 

 London, 670 feet in diameter, the water on an 

 absolutely still day has a glassy surface, but any 

 breath of air sufficient to be felt upon the cheek 

 is enough to ruffle its surface and to do away with 

 the mirror -like reflection. It will then be seen 

 that the area of ruffled water has been instan- 

 taneously covered with an almost uniform pattern 

 of little waves about an inch in length from crest 

 to crest. As the minutes pass during which the 

 breeze continues, the height and length of the waves 

 to leeward increases, but those on the windward 

 edge of the ruffled water remain of the original size. 

 Soon the whole pond, except a few feet at the 

 windward end, is covered with waves travelling 

 before the wind whose size increases regularly from 

 the windward to the leeward shore. The maximum 

 size attained at the latter place depends to some 



