THE ICE AGE. 323 



tation, but they are also discovered capping the cliffs of mountain- 

 chains, hanging by the side of depths, over which they must have 

 been carried, and into which, by the Nemesis of destiny, they are now 

 doomed to fall. The Jura Mountains, north of the great valley of 

 Switzerland, and opposite the western or Bernese Alps, along the fron- 

 tier of France, are thus studded with these bowlders, some of them 

 containing 50,000 to 60,000 cubic feet of stone. These have come from 

 the Alps ; they are crystalline rocks, gneiss, and granite, and they lie 

 upon ridges of limestone. They are virtually nothing less than dis- 

 located fragments of those abraded and decreasing hills perched 

 upon the Jura cliffs. Prof. Guyot has placed, beyond all doubt, their 

 home upon the summits and sides of the Swiss Alps, and shown that 

 they have attained their present eminence by a positive carriage from 

 these original localities. This position has indeed been made impreg- 

 nable by a protracted and laborious survey of innumerable " wander- 

 ers " found upon the Juras, whose lithological character identified 

 them with the Alpine formation, while it served to trace the probable 

 path of their transmission. These blocks have been found at eleva- 

 tions ranging from 2,000 to 3,500 feet above the sea, and in Carinthia 

 similar erratics have been described at great elevations, proceeding 

 from an opposite quarter of the Alps. 



. In North America, and especially throughout the Northern States, 

 the bowlders are numerous, often of great size, and indicating transits 

 of many miles. Over the Eastern, Middle, and Northwestern States, 

 bowlders, that have emigrated from distant points to the north- 

 ward, occur in such abundance that they may almost anywhere be 

 found if the inquirer will only examine the country he passes over. 

 Upon Mount Katahdin,in the Moosehead region of Maine, stones can 

 be seen, lying over 4,000 feet above the sea, fossiliferous in their na- 

 ture and coming from northern sites ; while toward Mount Desert, 

 masses, some forty to fifty feet in height, are sprinkled everywhere, 

 and, as in the case of the Dedham granite distributed to the south, in- 

 variably show northern origin. In Berkshire County, Massachusetts, 

 these traveled rocks lie in long alignments, passing over the Lenox 

 Hills, and extending in a generally southeasterly direction for fifteen 

 or twenty miles, and have been filched from the Canaan and Richmond 

 Hills across the line in New York, being of chloritic slate, with angu- 

 lar specimens of limestone intermixed. Some granites from Vermont, 

 on the west of the Green Mountains, have been lifted over these bar- 

 riers and transferred to the southern margins of Massachusetts ; while 

 in Vermont a bowlder weighing over 3,400 tons, and known as the 

 Green Mountain Giant, has been drifted from the Green Mountains 

 easterly across the valley of the Deerfield River, and planted 500 

 feet above that stream. In Michigan, near the Menomonee River, a 

 field upon the northern slope of a mountain is densely covered with 

 bowlders, so that a mile can be traversed without once touching the 



