PREFACE 9 



Most of Part III., relating to tidal bores and 

 other waves in rivers, was published in the 

 Geographical Journal and in Engineering in 1906, 

 but Parts I. and II., which relate to waves of the 

 sea, are new, and were written in 1909-10. 



Side by side with the observations of water 

 waves, I have during the same period (i.e., since 

 1895) been investigating the progressive transverse 

 ridges which are produced in sand and snow by 

 the action of water or wind, and I have made 

 observations upon earthquakes and other wave- 

 phenomena which come within the province of 

 physical geography. These I intend to publish 

 later. 



August, 1910. VAUGHAN CORNISH. 



