INTRODUCTION. 



The Physical Geography of the Sea is a new department of hnman 

 knowledge. It has resulted from that beautiful and admirable 

 system of physical research, in which all the maritime nations 

 have agreed to unite; and for the furtherance of which bureaux 

 have been established, especially in Holland, England, France, and 

 the United States. 



Consequently, research has become very active in this field ; it is 

 dihgent, too ; and in proportion to that activity and that diligence 

 has been the advancement of om^ knowledge concerning the physical. 



GEOGRAPHY OF THE SEA AND ITS METEOROLOGY. It may be doubtcd 



whether progress in any department of science has been more rapid 

 than it has been in this. 



The first treatise upon this subject appeared in America six 

 years ago. Since then such has been the richness of the harvest 

 of facts gathered, that the work has undergone frequent amend- 

 ments and improvements; indeed, within that time it has been 

 almost entirely re-written thrice. This re- writing was necessary 

 because it is a main motive with the author to have the work keep 

 pace with the science itself. The consequence has been, that each 

 re-cast has reaUy made a new work of it. 



The present edition is not only greatly enlarged above its pre- 

 decessors, but it is believed to be greatly enriched and improved 

 also. It may even be doubted whether in the variety, extent, and 

 value of the information now for the first time presented toucliing 

 the sea and an, this edition is not so far in advance of former 

 editions as really to make this a new work. Where error has 

 been found in previous editions, it has been corrected in this, — 

 where further research has confirmed opinions that in them were 

 ventured as such, the confirmation is here given. 



The present edition contains a number of chapters entirely new 



