66 AN OUTLINE OF THE 



Desert range exposes a large surface of bare rock. In 

 many parts of New England, the till is accumulated in 

 large rounded hills, of oval outline and smoothly rounded 

 profile, called by the Irish name, drumlins. These are 

 common in the neighborhood of Boston, and further inland 

 about Brookfield and Pomfret; but with half an exception 

 they are absent on Mount Desert. This half exception is 

 the long smooth northern slope of Beech Hill, southwest 

 of Somesville; apparently a deposit of till simulating a 

 half-drumlin form, extending only northward from the 

 rocky knob of the hill summit ; while to the south, where 

 a completed drumlin would descend symmetrically, there 

 is a rocky slope. 



Under the ice and in its lower part many blocks were 

 moved from their native ledges ; the preglacial soil was 

 scraped off, and the rock beneath was rubbed down. Val- 

 leys were deepened and hills were degraded ; but by com- 

 paring regions inside and outside of the glaciated area, it is 

 plain that as a rule no great erosion of hard rocks must be 

 attributed to glacial action. The excavation of our valleys 

 in the uplifted peneplain was a large piece of work com- 

 pared to the scraping of the surface by the ice sheet ; and 

 the time required for the valley making was much longer 

 than the duration of the ice invasion. Yet on Mount 

 Desert there are certain considerable topographic features 

 whose origin has no other explanation than excavation by 

 the rough-shod ice. These are the deep transverse valleys 

 by which the mountain range is so curiously divided. In 

 its moderate length of twelve miles, it is notched almost 

 down to or beneath sea level no less than nine times. 

 Instead of a mountain ridge as continuous as the granite 

 of the central belt, we have a beautifully diversified succes- 

 sion of rounded domes, separated by deep gorges ; and in 

 nearly every gorge there is a lake or an arm of the sea, 

 almost directly in the axis of the range. There is no 



