PREFACE TO FIRST EDITIOX. 



The present treatise is the outcome of special studies 

 upon glacial phenomena begun in the summer of 1874, in 

 the eastern part of Massachusetts, the results of which 

 were published in a communication to the Boston Society 

 of Natural History in December. 1S76. These first studies 

 pertained to the origin of the gravel-ridges described in 

 this volume under the name of ,, karues." Fortunately. 

 in the preparation of that paper, I was favored with an 

 interview with Mr. Clarence King, who then gave me the 

 information referred to in the following pages, concernino- 

 the terminal moraine south of Xew England, which has 

 been so fruitful of suggestion to other investigators as 

 well as to myself. Since that time the subject has never 

 been out of mind, and my summer months have all been 

 devoted, under favorable conditions, to the collection of 

 field notes regarding it. and so it has seemed to others, as 

 well as to myself, appropriate that I should endeavor to 

 bring the facts within the reach of the general public. 



After having become, during the four following sea- 

 sons, familiar with the glacial phenomena over the larger 

 part of Xew England. I was invited by Professor Lesley 

 to survey, in company with the late Professor II. Carvill 

 Lewis, the boundary of the glaciated area across Pennsyl- 



