INTRODUCTION.
The Physical Geography of the Sea is a new department of human 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 diligent, too; and in proportion to that activity and that diligence has been the advancement of our knowledge concerning the PHYSICAL GEOGRAPHY OF THE SEA AND ITS METEOROLOGY. It may be doubted 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 amendments 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 really made a new work of it.
The present edition is not only greatly enlarged above its predecessors, 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 touching the sea and air, 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 and not to be found in any of its predecessors. Most, if not all
