SCIENTIFIC SURVEY. 



383 



age ; for the irruption of the trap of North Haven broke through 

 the granite and Taconic slates in a line corresponding to this trend, 

 as you and I agreed, I believe. 



We also find the hills not rounded and rough, but having an 

 elongated appearance, and a trend also north-south, as if their 

 sides had been subjected to a gigantic system of sculpturing, on 

 the design that thes-^, too, should be directed towards the south. 

 And furthermore, these hills, even where they attain an elevation 

 of one and two thousand feet, as those of Camden and Mount 

 Desert, present gradual slopes to the north and bold fronts to the 

 south ; and if of granite, they are broken down more or less into 

 step-like precipices of east-west parallels, the debris of which has 

 not been accumulated as tali, but has been transported south a 

 little distance, often more and more comminuted as we advance. 



The formation of the coast is syenitic granite, bordered here 

 and there with a margin of trap or of Taconic slates, highly alter- 

 ed in cases, and often converted into cherty flints as on Isle au 

 Haut — and furnishes from the general barrenness of the surface, a 

 good opportunity to study the boulder phenomena. And this sur- 

 face is everywhere ridged into furrows, often very deep and in the 

 usual direction of the valleys, &c., and present the finest examples 

 of embossed rocks as described by Charles H. Hitchcock, in his 

 Elements of Geology. This is so remakably the case that one 

 might in the foggiest weather, easily point out north, south, &c., 

 by looking at these rocks ; for they represent in miniature, the hills 

 and mountains of the coast as I have described them^ Transverse 

 indentations are everywhere common — lunoid fun^oivs, I have called 

 them — from an inch in length to four and five feet, having their 

 horns pointing towards the north-east and north-west, and their 

 steep walls facing the south. These furrows in all cases, are suffi- 

 cient to tell the cardinal points of the compass as one passes along 

 over them. 



Everywhere, too, the boulder strije may be found on the south 

 sides of these hills at their bases, and on their sides when dipping 

 at steep or lesser angl-es towards the east or west, in as finely de- 

 veloped examples as are found on their northern slopes. It is a 

 fact beyond controversion, that the boulder phenomena in the Pe- 

 nobscot bay are sui generis in character, and owe their existence 

 to one agent and the same period. 



I have found these boulder strife four hundred feet high on the 



