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216 



IJULLKTIN OF THE 



marked, is to bo ascribed 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 accounl for the existence of a great piano 

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

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

 one, provided the weight of proof in support of such an hypothesis is 

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

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

 a brief piper like this, whoso 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 mateilal. The present Soutliwest Slide proper ~ the loose slide 

 begins a little above the point where the old avalanclie 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 ahout 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 course 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 ^S[) feet (mean of two observations) higher tlian its foot, 

 the inclination of the slopes between tlic terraces varies upwards from 

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

 rock-pilod surface, from the head of the slide to the brow of the Tabl^e 

 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. 



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

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

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

 c»f the iq.per fourth, 30°. Its foot lies about 200 feet lower than tlio 

 level of the I5asin Pond, and its head is 1,000 feet above the same level, 



-*■ A landinurk coasi.iciious for miles down llu; VcmUc.ni, and vecoginzablc i.i 

 pliotograpliH. 



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