216 BULLETL\ OF THE 



marked, is to be asci'ibed ultimately to the high inclination of the con- 

 centric sheets of granite ; but there is absolutely nothing in the rock 

 structure that will help to account for the existence of a great plane 

 surface of above five hundred acres, like that of the Table Land. The 

 supposition that it is the work of moving ice is a natural and rational 

 one, provided the weight of proof in suppoi't of such an hypothesis is 

 greater than that of proof antagonistic with it. But to cite testimony 

 for, or against, any particular theory, does not come within the scope of 

 a brief paper like this, whose chief purpose is the presentation of facts. 



Material interesting from its relation to the transportation of drift, 

 whatever may have been the agent that moved it from the north, is 

 not wanting upon Ktaadn. The two slides furnish the chief amount of 

 such material. The present Southwest Slide proper — the loose slide 

 — begins a little above the point where the old avalanche started, a full 

 half-mile below the brow of the Table Land, and terminates at the foot 

 of the most abrupt portion of the mountain. The length between the 

 points indicated, as estimated after repeated ascents and descents, is one 

 mile and three fourths. The width at the bottom is about 100 feet, 

 narrowing very slowly upwards. The difference of elevation between 

 the top and bottom is 1,774 feet, — the mean of two observations. In 

 its cour.se the slide exhibits several terraces, at places doubtless where 

 it conforms to the varying slope of the solid surface of rock over which 

 it passes. The inclination, therefore, is variable. As tested with a 

 clinometer at several points, it appears to be as follows. From the foot 

 to the " Green Island," * a small bush-grown patch upon the surface of 

 the slide, and 985 feet (mean of two observations) higher than its foot, 

 the inclination of the slopes between the terraces varies upwards from 

 24° to 28° ; thence to the top it is 31°. The average inclination of the 

 rock-piled surface, from the head of the slide to the brow of the Table 

 Land, is 35°, but the last seven minutes' climb is upon a slope of 47°. 

 Along the lower two thirds of the slide, drift is distributed in consider- 

 able quantity, but on the upper third it is rarely seen, and disappears 

 entirely before the top is reached. 



The East Slide is less than a mile long, and is one continuous slope, 

 uninterrupted by terraces like those of the Southwest Slide. The in- 

 clination of the lower half was found to be 25° ; of the next fourth, 28°; 

 of the upper fourth, 30°. Its foot lies about 200 feet lower than the 

 level of the Basin Pond, and its head is 1,000 feet above the same level, 



* A landmark conspicuous for miles down the Penobscot, and recognizable in 

 photographs. 



