138 G. H. Stone — Wind Action in Maine. 



at Bethel bowlderets and smaller stones were held so long in 

 one position in the ice as to be sand-carved, then, either such 

 sculptured surfaces ought to be common in the kames, or we 

 must re-cast our theories as to the kames being deposited by 

 glacial streams. During an investigation of several years, the 

 writer has failed to find a well marked instance of pure sand- 

 sculpturing in the kames and osars, though now and then there 

 are indistinct traces of it. 



During the past summer the writer, in the course of an in- 

 vestigation of the glacial gravels of the region, has explored 

 the Androscoggin valley from Brunswick to the N. H. line. 

 Incidentally the Bethel mystery was solved. In numerous 

 places, both in Bethel and elsewhere near the mountains, I 

 found bowlders and even small stones which are now being 

 sand-carved by the wind as plainly and incontestably as in Col- 

 orado. The drifting dunes of fine sand do not produce this 

 effect to any great extent, probably because the stones are cov- 

 ered and uncovered too rapidly. But there are bare spots not 

 protected by grass where coarse sand and gravel are driven 

 back and forth by the wind, and here the carved bowlders can 

 be seen in considerable numbers and in all stages of the pro- 

 cess. In some cases it appeared probable that these bare places 

 were where drifting sand had swept over the surface and the till 

 had been partially denuded by the wind in the manner before de- 

 scribed. It now became evident why one face of the Bethel 

 bowlders is in most cases unpolished. That rough face was the 

 under surface, and was protected from the attrition. If a 

 bowlder, after having its exposed faces polished, was rolled 

 over by the up-turning of a tree or by any other cause, the 

 other face or faces became polished also. Where a bowlder lay 

 deep in the ground only a small part at the top could be pol- 

 ished. If it lay on the surface evidently every face except 

 the bottom could be carved simultaneously, provided it was 

 not too large. Large bowlders are only carved laterally ; their 

 tops, being above most of the flying sand and gravel, weather 

 faster than the progress of the attrition. The freshness of sur- 

 face noted by Dr. True is clue to the fact that the process 

 is recent. Indeed every feature of the Bethel bowlders under 

 consideration is fully accounted for by the hypothesis of sand- 

 sculpturing under the action of the wind. An accessible 

 locality for observing the process of sand- carving now in oper- 

 ation is found about one mile from West Bethel on the east 

 side of the road leading to Mason. The fields around Bethel 

 village have so generally been plowed that one finds it hard to 

 determine their orio-inal condition. 

 U. S. Geological Survey, October, 1885. 



