D 



PREFACE 



The object of this book is to introduce unprofessional 

 students of nature to certain interesting phenomena of the 

 sea-shore and of the depths of the ocean. In no other 

 fields are large and important truths which are distinctly 

 related to human interests so readily to be traced ; yet the 

 treatises which deal with these matters are few in number, 

 and generally of a recondite character. 



The aim of the writer in preparing the essays which are 



* here presented has been to separate from the great body 



E of technical knowledee concerninsf shores and seas those 



features which have value for the reason that they may 



g, serve to enlarge the reader's conception as to the methods 



i of nature. As commonly observed, or as learned from text- 



5 books, these truths appear to be fragmentary and lead to 



": no extended notions as to the workings of the earth's 



i machinery : thus the student is not led to form those con- 



i ceptions which it is most important that he should gain. 



I In part the matter presented in the following pages has 



- been printed in Scribner's Magazine. That especially relating 



' to harbors, which is contained in the three last chapters, is 



mainly extracted from a report on the Geological Mistory 



of Harbors, which was printed in the Thirteenth Annual 



Report of the Director of the United States Geological 



Survey. The author and publisher are alike indebted to 



that Survey for permission to use the text and the plates 



which appear in this part of the book. 



431733 N- ^"^^ s- 



