INTRODUCTION. 



Norwegian seamen often speak of a strange phenomenon which they call 

 "dodvand" or dead-water, and which without any visible cause makes the 

 vessel lose her speed and refuse to answer her helm. Their only definite 

 knowledge of its origin is that it exists solely at places where the sea is co- 

 vered by fresh or brackish water. The same phenomenon is known by sea- 

 men in other countries although to a much smaller extent; but most people 

 have certainly never heard of it. The tales of dead-water have often been 

 regarded as mere fictions of the imagination. 



When the From made her way along the Siberian coast in the autumn 

 of 1903, she three times met with dead-water off Taimur Island. This occur- 

 ence made Prof. Nansen very desirous of having the causes of the pheno- 

 menon cleared up, and it led, as mentioned in the Preface, to Prof. V. Bjerk- 

 nes' explanation of the phenomenon and to the present investigation. If the 

 objective reality of dead-water may now he acknowledged as an undeniable 

 fact and if its causes are, in the main, known, they may certainly be reckoned 

 among the scientific results of the first Fraw-expedition. 



In addition to the collective description of the dead-water, which intro- 

 duces Chapter I, the original accounts are frequently inserted in detail, and 

 for two reasons: 



1) The narratives are not in every detail quite in accordance with one- 

 another, and it was not possible always to decide in what degree the features 

 of the phenomenon itself, are variable, or what descriptions are the most cor- 

 rect. They ought therefore to be accessible to the reader's criticism. 



