Preface xi 



provided at the end of each sub-chapter concerning the hterature sources used and can 

 be considered as unique in their completeness. 



A presentation of instruments and apparatus in use in oceanographic research, their 

 technical function and instrumental theory, was not intended to be included in the 

 textbook. Since the different nations engaged in oceanographic research mostly use 

 their own instruments and apparatus, it would be rather difficult in the frame of such a 

 textbook to deal with all instruments and explain their function. I beheved this to be 

 unnecessary since much has already been summarized by authoritative institutions and 

 also because a detailed textbook on oceanographic instrumentation has been com- 

 missioned from the international side. 



The contents of the book formed the basis, as already mentioned, for my lectures on 

 physical oceanography held at the University of Berlin Institute and Museum for 

 Oceanography (1927-1942); later on, until 1953, they were the basis for my lectures 

 held at the University of Innsbruck, Austria, Institute for Meteorology and Geophy- 

 sics and, after my retirement, lectures at the University of Hamburg and the Free 

 University of Berhn, where I was invited as an honorary professor. 



The internal structure of the text resembles the old text of the well-known and, in its 

 time, excellent Handbook of Oceanography by O. Kriimmel (E. Engelhorn, Stuttgart, 

 Vol. I, 1907, Vol. II, 1911). This two-volume work is outdated in all of its parts and 

 had to be replaced in time by a completely revised modem text corresponding to our 

 present knowledge of the oceans. In one respect the text under consideration differs 

 fundamentally from Kriimmel's book since no attempt was made to deal in the 

 present book with historical and older work about oceanic phenomena and with 

 attempts to explain them in such minuteness of detail. Most of Kriimmel's material, 

 as will be understood, deserves at present only historical interest and would have been 

 for my book only unnecessary ballast. The reader who has a special historical interest 

 may therefore be referred to the text of Kriimmel. 



Being fully aware that not aU the chapters of my work will perhaps be quite to the 

 taste of my oceanographic colleagues, I have always tried to present everything which 

 may still be of value for the further development of oceanography. I may best speed 

 this book to the reader with the words, splendid due to their simphcity, of the great 

 Newton : 



"Ut omnia candide legantur, defectus in materiam tam difficile non tam reprehen- 

 dantur, quam novis lectorum conatibus investigentur, benigne suppleantur, enixe 

 rogo." 



"I heartily beg that what I have here done may be read with forbearance ; and that my 

 labours in a subject so difficult may be examined, not so much with the view to censure, 

 as to remedy their defects." 



"Mogen Mangel in einer so schwierigen Materie den Leser weniger zum Tadel als zu 

 neuen Versuchen und gefalhger Erganzung veranlassen! Um das bitte ich denselben 

 recht dringend." 



A. Defant 



Innsbruck, 

 March 1960 



