m 



Portland and its Vicinity. 



345 



agency in the naked rocky islands and' shores, especially 



Marbl 



As we enter Boston har- 



banks of a river which the stream is wearincr away 



bor, a curious phenomenon presents itself. The outer- 

 most islands, as the Graves and the Outer Brewsters, are 

 composed of naked rock, or nearly so. But those more 

 within the harbor, are covered with a thick diluvial coat ; 

 except that on their northeasterly, northerly, and north- 

 westerly sides, the sea is encroaching upon this diluvium, 

 so that the shores are precipitous, appearing like the 



No 



such denudation is exhibited on those islands, which, by 

 being more within the harbor, are protected from the 

 fury of the waves ; nor, ^6 far as I have observed, does 

 any other than a northern or eastern shore present this 



w 



appearance ; showing clearly, tliat it results from north- 

 easterly storms. 'Nor can a doubt remain but that the 



t 



outermost islands have, by the same process, been swept 

 of their diluvial coat. Indeed, who can doubt but nearly 

 the whole coast of Essex county, and I might add, of a 

 great part of the coast of Maine, has been thus denuded. 

 Amid the rapidly changing scenery of Boston harbor, as 

 we pass through it in a 



moment the sketch below. But I am not sure whether 



steam 



the group of islands represented is that of Calf' Island, 

 the Great Brewster, &c. or Lovell's, Gallop's, &c. The 



VOL. I PART III. 



45 



■^ 



