112 WAVES OF THE SEA 



a speed of 30 statute miles per hour. Thus, during 

 the first day the air blew over the travelling wave- 

 crests at 16 statute miles per hour, and during 

 the last day at 3 miles per hour. 



During the storm in the Southern Indian Ocean 

 (described on p. 73) Captain David, of the 

 S.S. Corinthic, estimated the average length of 

 the waves at about 675 feet, which corresponds 

 to a wave velocity of 40 statute miles per hour. 

 The wind was logged as 9 on Beaufort's scale, so 

 that its average velocity must be taken as 

 44 statute miles per hour. The air, therefore, 

 blew over the ridges of the travelling waves at 

 an average speed of 4 statute miles per hour. 



During the storm in the North Atlantic (de- 

 scribed on p. 42) the wind was recorded by 

 Scoresby on March 5th as a " hard gale," which 

 I take to be the same as a " strong gale," number 9 

 on Beaufort's scale, corresponding to an average 

 velocity of 44 statute miles per hour. Now, the 

 average length of the waves measured by Scoresby 

 on March 6th was 560 feet, corresponding to an 

 average velocity of 38 statute miles per hour. The 

 ship, which was running before the wind, had 

 then been exposed to the gale for about 40 hours, 

 but the force of the gale had by this time some- 

 what abated. When the gale was at its height 



