124 WAVES OF THE SEA 



to the reinforcing action of the wind. The waves 

 whose speed is identical with that of the travelling 

 disturbance will be continually subject to the re- 

 inforcing action of the wind during the whole life- 

 time of the cyclone. I think, therefore, that the 

 wave-length of the principal, or dominant, or 

 storm-wave generated in Atlantic storms should 

 depend, not only upon the velocity of the wind, 

 but also upon the rate of advance of the cyclone. 

 It is, I believe, a matter of common remark that 

 in some storms a short, steep sea is soon formed 

 and in others a longer sea. 



The general rate of advance of Atlantic storms 

 towards our shores has been investigated, 1 and the 

 figures are worth examining in connection with our 

 subject. Storms advancing from points between 

 WSW. and WNW. to ENE. and ESE. travel at 

 an average speed of 28.9 statute miles per hour. 

 Of the 264 storms examined, only 60 travelled at 

 more than 35 statute miles per hour, and of these 

 only 10 travelled at more than 52^ statute miles 

 per hour. 



It appears, therefore, taking the average of a 

 large number of storms coming from the Atlantic, 

 that waves travelling about 30 statute miles per 



1 Q.y.R.M.S., 1902, he. oil 



