vi PREFACE 



heard him discourse in glowing words of starfish and 

 nudibranchs at the Isle of Man, of the graceful medusae 

 of the Clyde sea-lochs and of dredging with Goodsir and 

 MacAndrew in the Hebrides — and so felt that I too had 

 dwelt in Arcady. 



The book is really based upon a course of about twenty 

 public lectures given in the winter of 1919-20 while I held, 

 for the first year, the newly established Chair of Oceano- 

 graphy in the University of Liverpool. The purpose of the 

 lectures was to put before my colleagues and students what 

 I regarded as the scope and nature of this new university 

 subject, and to interest the public of Liverpool in the deeper 

 knowledge of the seven seas that mean so much to that 

 great port, by giving examples of the phenomena and some 

 explanation of the methods of investigation of the problems 

 of the ocean. 



The book follows the same lines. The first half-dozen 

 chapters are in the main biographical, dealing with the 

 lives and work of some of the leading men who have made 

 our science ; and those were selected in regard to whom 

 I had something to say at first hand. The remaining 

 chapters treat of subjects rather than men, and here again 

 I have had to be eclectic and have deliberately limited 

 myself, in the almost science-wide as well as world-wide 

 range of Oceanography, to those matters in which I was 

 myself most interested, and about which, as one had found 

 in lectures and conversation, the intelligent non-specialist 

 inquirer for information in regard to the sea wanted to know 

 more. The treatment of the matter, then, is not intended 

 to be exhaustive even in the subjects chosen. The aim 

 is rather to show that the field of inquiry is wide and varied, 

 that the phenomena observed — many of them familiar to 

 ocean voyagers — are all matters requiring scientific in- 

 vestigation and are frequently interdependent, so that the 

 explanation of one requires a knowledge of another, as in 

 the case of the migratory fish and the distribution of 



