INDEX 373 



WATERFALL 



Sounds of, 334 



Breaking of water in, 334-346 

 Waves of the sea 



Height of, in relation to length of fetch of wind, 67 



Height of " swell " during storms, 96 



Average height in relation to velocity of wind, no. See 



also under localities, as " Atlantic," " Pacific," &c. 

 Length of, discrepancy between wave-lengths determined 



by simultaneous and by successive observations of 



wave-crests, 78 



Length of swell which reaches the shore after storms, 85 

 Co-existence of waves of different lengths, 101 

 Calculation of wave-length. See under Formulae. See also 



under localities, as " Atlantic," " Pacific," &c. 

 Mountainous appearance of, 137 

 Number of, in a single series. See under localities, also 



pp. 88-96, 126-127 



Period of, mathematical relation to wave-length, 25 

 Periods of swells observed from near Bournemouth, 



87-93 



Periods of swells observed from north coast of Ireland, 

 93-96. See also under localities, as " Atlantic," 

 "Pacific," &c. 



Undertow of, 166 



Velocity of storm waves in relation to average velocity 

 of wind, in 



Velocity of swiftest swells in relation to highest wind- 

 velocity, 119 



Velocity of waves and swell in relation to rate of 

 advance of a cyclone, 121 



Velocity in relation to depth of water, 85 



On group-velocity, 94, 119 



Action of, to transport mud, 141 



Action of, to transport sand, 158 



Action of, to transport shingle, 146, 176 



