X. Preliminary Report on the Recent Changes of Level on the Coast of 

 Maine : vAth reference to their origin and relation to other similar changes} 

 By N. S. Siialer. 



introduction. 



X OR many years there have J^een frequent reports of changes in the level of rocks and 

 shoals on the coast of Maine. Generally these accounts have been of an untrustworthy 

 nature, inasmuch as they seemed framed in palliation of some blunder of seamanship. A 

 vessel being cast away in some well-known waters, it was natural enough for her captain to 

 claim that the rock was not there before ; or that the dejjth of water had greatly dimin- 

 ished Avithin recent times. Every sailor who had excused his own blunders in this fashion, 

 was naturally inclined to foster the opinion that the rocks were growing nearer the surface 

 year by year, and without any intended deception one can easily imagine that in time a 

 decided conviction might thus be reached. Experience in other regions has shown, how- 

 ever, that a prevailing opinion of this kind is apt to have some foundation. For some 

 centuries the popular belief of the inhabitants of the Scandinavian coast concerning the 

 changes of level of the shore, received no scientific examination ; when, however, these 

 questions were approached in a determinate fashion, it soon was made evident that the 

 popular opinion was smgularly correct, both as regards the extent and character of the 

 movement. The following considerations, and the facts upon which they are based, result 

 from a tolerably careful study of the record of changes along the New England coast, and 

 from several years of summer labor. 



Before giving a detailed account of the facts observable on the coast of Maine, it will be 

 well to consider the general nature of the changes of level which have been observed in 

 neighboring countries. I shall therefore give a brief resume of the facts concerning eleva- 

 tions and depressions of shore lines in the north Atlantic section of our own continent, and 

 those of the opposite continent of Europe. From the time that geology began to exist as 

 a science, it has been a well-accepted fact that the surface of the diy land has been con- 

 tinually changing its level with reference to the sea. It is, however, among the later inves- 

 tigations that we begin to find anything like a careful study of the last, and therefore the 

 most easily determinable, changes which our continents have vmdergone. Although by no 

 means complete, these investigations enable us to assert, with a precision -which can rarely 

 be obtained in the science, that a groat movement of elevation has taken place throughout 

 the whole northern section of the Atlantic coast line, in the most recent times. The 

 quantity of the vertical movement varies greatly in different places ; it seems, however, to 

 be quite certain that the elevation is generally greater as we advance towards the north. 



1 Published by permission of the Superintendent of the U. S. Coast Survey. 



MEMOIRS BOST. SOC. NAT. UIST. VOL. II. 81 



