CHAPTER IV 



The velocity of the wind at sea The numerical relation 

 between velocity of wind and average height of waves 

 The relation between the velocity of the wind and the 

 velocity of the waves The connection between the rate of 

 progress of cyclones and the character of the waves The 

 effect of squalls and gusts upon waves On wave-fronts 

 in a veering wind, and on the irregularity of the waves in 

 the region of the Trade winds The observed profile of 

 waves at sea The mountainous appearance of waves. 



The Velocity of the Wind at Sea 



IN order to arrive at an opinion upon the rela- 

 tion between the velocity of the wind and the size 

 and speed of the waves of the sea, we have to rely 

 mainly upon the conventional numbers entered by 

 the navigating officer in the ship's log, by which 

 he expresses the force of the wind as he judges it 

 to be. The watch on the bridge being of four 

 hours' duration, the number generally represents 

 the average force of the wind throughout this time. 

 The connection between these conventional num- 

 bers and the velocity of the wind has been deter- 

 mined by experiments with anemometers. In the 



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