44 WAVES OF THE SEA 



of the observer's eye . Sometimes a crest extending 

 in a ridge 100 yards long would be from 2 to 3 

 above the invisible horizon. This Dr. Scoresby 

 says would give a height from trough to crest of 

 more than 40 feet, but I confess I regard this 

 rather as a guess than a measurement. Sometimes, 

 he says, the crossing of two wave -crests would 

 send up a sharp peak of water to a height which 

 he believed to be 50 or 55 feet, or the crest of a 

 breaking wave would shoot up to a similar height. 

 The average height of the waves during the 

 observations on March 5th was more than 30 

 feet. 



On the following day, when, the wind being 

 less violent, the waves had subsided to an average 

 height of 26 feet and were more regular, Dr. 

 Scoresby determined the wave-length in the follow- 

 ing indirect manner. The waves overtook the ship 

 every 16.5 seconds and each wave took 6 seconds 

 to run the whole 220 feet of the ship's length. 

 Then the distance between two succeeding wave- 

 crests as thus observed was : 



220 x ^g-5 = 605 feet ; 



but the ship was not running in exactly the same 

 direction as the waves, and a line from crest to 



