12 PREFACE 



canic rock which so greatly hamper work on the 

 Panama Canal by bulging up the bottom of the 

 Culebra Cut, and I am now pursuing the study 

 of this kind of wave. 



My observations have been communicated from 

 time to time to the Royal Geographical Society, the 

 British Association, and the Royal Society of Arts, 

 and will be found in their Journals and Proceed- 

 ings from 1896 to 1913.^ My observations of 

 water waves, up to 1909, have also been published 

 in book form,^ and the present volume contains 

 those on waves of sand and snow. 



That waves, progressive transverse inequalities, 

 should be produced by wind in sand and snow is 

 a strange thing, which ought to excite our sur- 

 prise, for the familiar action of wind upon loose 

 bodies is of the opposite kind. First, it blows them 

 from salient to sheltered positions, thus tending to 

 obliterate transverse inequalities ; secondly, it finds 

 out weak places in materials which it is capable 

 of eroding, gouging out grooves, which it lengthens 

 until it has driven through a longitudinal furrow. 

 Thus the more familiar action of wind is to 



' See Appendix, catalogue of original papers by the author. 

 ' " Waves of the Sea and other Water Waves." By Vaughan 

 Cornish. PubHshed by Fisher Unwin, 1910. 



