110 WAVES OF THE SEA 



The Numerical Relation between Velocity of Wind 

 and Average Height of Waves 



The heights of waves discussed in detail in pre- 

 ceding chapters are those produced when the wind 

 has had opportunity to develop them fully, and most 

 attention was given to the size of the maximum 

 waves then produced. Circumstances frequently 

 prevent the waves from attaining the full size which 

 the velocity of the wind is capable of producing 1 , 

 of which fact examples were noted in my voyage 

 on the Ivernia (p. 53). The numerical relation 

 between the velocities of wind and average height 

 of wave, obtained from the records of daily obser- 

 vations on long cruises, depends in part on 

 cases where the velocity of wind has no physical 

 relation to the height of the waves. Such averages, 

 therefore, blur the truths, which the writer, as a 

 student of physical geography, desires to eluci- 

 date. There is, however, a practical point of view 

 from which these averages may be useful that, 

 viz., of the naval architect. As the ships which 

 he designs may have to sail on any seas and to 

 encounter all weathers, it is sometimes desirable 

 to eliminate local conditions. 



The tables given in my paper in the Geogra- 

 phical Journal, May, 1904, show how closely con- 



