PREFACE 



In different oceanographic investigations during recent years we 

 have been confronted by a series of important questions relating 

 to the reciprocal action between the sea and the atmosphere. We 

 have formed a plan of examining these relations more closely in 

 the hope that we may thereby make some contribution to the under- 

 standing of climatological variations. 



In the present work we have examined some of the purely 

 oceanographic relations which are important in the problem and 

 we have also made a series of investigations on the climatological 

 variations themselves. These studies, however, form only the first 

 and introductory part of a greater investigation, and we do not 

 now endeavor to give a final solution of the problem. In a later 

 continuation of the investigation we hope to penetrate deeper into 

 the question, which indeed for its thorough discussion demands 

 such an enormous mass of material that we have not as yet suc- 

 ceeded in collecting it. 



In our endeavor to gather information relating to the Atlantic 

 Ocean we have been so fortunate as to find in Herr Adolf H. 

 Schroer an interested and helpful colleague. He has repeatedly 

 made journeys to Hamburg in order personally to promote the 

 arrangement of the great quantity of observational material which 

 we have obtained at the Deutschen Seewarte there, as a starting 

 point for our investigation. We ofifer to him our best thanks for 

 this valuable help which he has given us. 



We also give our warmest thanks to the officials of the Deutschen 

 Seewarte for the willingness with which they have put their great 

 collection of ships' log-books at our disposal as well as for the 

 great kindness with which they have facilitated the extraction of 

 data from them. 



The Authors. 



June, 1917. 



VIII 



