With an increasing wind velocity, 

 the shorter, capillary waves de- 

 crease rapidly in contrast with 

 the increasing gravity waves, 

 until with wind velocities of about 

 90 to 100 cm par second they 

 practically disappear » It is 

 indicated that waves with the 

 maximum stable steepness ratio 

 (height to length) of 1 to 7 are 

 attained with a wind velocity 

 of about 122«7cra» par "nnnd . 

 The plot in Figure 

 itlal waves with th 

 Tables II a and b g 

 puted time required 

 itial wave to "matt.. 

 or to grow to a stationary con- 

 dition, for wind velocities of 80 

 and 122 »7 cm. oer second 



(cm) 



1.2-15 



a (crro 

 -25 



-20 



2c B i 



T&e 3rd sentence should read; "The plot in 

 Figure 1 shows graphically the variation of the 

 wave length and stationary height for initial 

 waves with the wind velocity." 



0.2- . 



Figure 1 - Wave length \ and wave 

 height 2 a with stationary in- 

 itial waves in their dependency on 

 the wind velocity v. 



Further computation has been 

 made by the author for the gen- 

 eration of waves by winds over 

 shallow water layers, or where 

 the wave length is greater than 

 the water depth . It is signifi- 

 cantly shown that as the water 

 depth because for a given wind velocity the length of the initial waves 



jGomes shorter, and the wind velocity necessary for the generation of 

 clearly recognizable wave trains becomes greater. The time required 

 for "mature** waves to be genarated in shallow water depths is essential- 

 ly less than that required for greater depths. Table III gives, for 

 several water depths, the lengths of initial waves with a steepness 

 (amplitude divided by wave length) of 0«07, and also the wind velocities 

 required to generate these waves. 



TABLE II a 



1) Principal Wave ( A' - 3.71 cm.) 



a cm. 0.01 0.02 0.03' 0.04 0.05 0.055 



18.6 



t sec. 1.7 4.0 6.9 11.1 



2) Secondary Wave ( A = 0.80 cm.) 

 a cm 0,0005 0.0010 0.0020 0.0027 



26.7 



sec, 







0.09 



0.205 0.59 



1.86 



28 



