PREFACE 



MOST of us have felt the fascination of a wave. 

 The waves of the sea, which are the prototype of 

 all the phenomena which we now call waves, are 

 perhaps the most fascinating of all. Great as is 

 the beauty of their form, the mystery of their 

 motion is the greater charm. For while they move 

 they live and have a being, which, like our own, 

 is but momentarily associated with the matter of 

 which they are formed. The wave preserves its 

 individuality, its recognisable though not unchang- 

 ing form, its energy, partly active, partly in reserve, 

 whilst its material substance is constantly rejected 

 and renewed. Of all manifestations of the inor- 

 ganic world it is most like a living being. Yet 

 when we watch it to its end we find none of the 

 sad accompaniments of the exhaustion of life. It 

 is most beautiful at the last, as it culminates to its 

 fall and breaks in seething foam. 



There are two aspects of sea waves which parti- 

 cularly attract our admiration. The first is that 



