206 SURFACE GEOLOGY. 



tion of the Mt. Washington hotel. In laying the foundation of this edifice, — nearly 

 two hundred feet long, — the angular debris was first taken up and placed in the cellar 

 walls. When this had been used up, the workmen reached the same moraine mass 

 which occurs below, along the carriage-road. Some of the earth was sandy, and went 

 into the composition of the mortar used on the walls. There was scarcely any ledge 

 requiring removal. I examined such of the stones as remained in the cellar as well as 

 possible with a dim lantern, and found everything in agreement with the character of 

 the materials seen two hundred and fifty feet lower along the carriage-road. The stones 

 assumed the ordinary glaciated shapes, but I did not discover any material foreign to 

 the mountain. One of the quartz fragments seemed to show traces of smoothing or 

 incipient striation. 



Next, I examined the excavations made for the road between the house and stables, 

 and obtained several small boulders, four or five inches long, corresponding in mineral 

 structure with the ledges in Randolph and Jeff'erson, twelve or fifteen miles away. The 

 general color of the rock is so like that of the mountain that one would not perceive 

 the difference between them without close inspection. The mica is arranged differently 

 in it ; the white parts are more abundant, though in fine grains, and the rock is evi- 

 dently the same with the upper member of what I call the "Bethlehem gneiss" in the 

 New Hampshire reports. The highest point at which stones of foreign origin were ob- 

 tainable may be twenty or twenty-five feet below the very pinnacle of the mountain. 

 Hence it is fair to conclude that every part has been covered by the glacial ice. The 

 glaciated stones, composed of the same material with that of the mountain, are com- 

 mon all along this road to the stables, and elsewhere in excavations over the summit. 



Being unexpectedly called away, I had not time to search carefully for striae upon 

 the ledges. Just beyond the signal station dwelling I found a flat ledge sloping a little 

 north-westerly but precipitous on the south-east. Atmospheric agencies have marred 

 the surface so much that no striae are visible, even if they ever existed. I had pro- 

 posed to scrutinize every harder projection of quartz with a lens, as this course some- 

 times reveals striation where other inspection is unavailing. Were this ledge situated 

 near the Lake of the Clouds, where embossment is common, I should point it out 

 unhesitatingly as an example of ice-sculpture, though much degraded by weathering. 

 The shape agrees with that of thousands of glaciated ledges in other parts of the state. 

 Other ledges on the mountain further north resemble this one. Inasmuch as the trans- 

 portation of materials is clearly proved by the presence of the Jefferson rock upon the 

 summit a few rods away, it will not be unreasonable to believe that this apparent em- 

 bossment is real. The altitude of the ledge is the same with that of the site of the 

 travelled stones. 



The disposition of the large blocks upon the summit is noteworthy. Several acres 

 of surface are covered by them far away from visible ledges. As you approach a ledge, 

 it is easy to see what fragments have been separated by frost action, as the projections 

 match the indentations ; and a very few feet of distance represent the extreme amount 

 of removal, save on a steep slope. Since the surface covered by the large angular 



