46 SUMMER IN A BOG. 



about these hills and swamps which takes pos- 

 session of me when once I get among them> so 

 that I find it impossible to tear myself away 

 until the last minute, when I look so disrepu- 

 tably frowsy that the only refuge is home, to 

 which I hurry. Have you discovered any charm 

 in their proximity yet?" 



"A great deal; and my son has shared his 

 study of their geological features with me, so 

 that I have thought of them in that way some- 

 what." 



"Professor, do you recall what we were 

 speaking about — the iceberg drift and Dr. New- 

 berry's theory in regard to this region?" 



"Ah! about icebergs carrying the boulders 

 of huge size? The views of Newberry given 

 forty years ago in regard to the ice period are 

 not accepted now in so far as they involve the 

 submergence of any part of central and south- 

 em Ohio, or involve iceberg action. The glacia- 

 tion of Ohio was by a continental ice-sheet alone, 

 though during the retreat of the ice large tem- 

 perate lakes formed against the ice front in the 

 Lake Erie region, and the margins of those 

 water bodies are shown by the 'ridges,' etc., in 

 northern Ohio." 



"Mrs. Wier," said I, "take time to consider 

 the word 'ice-sheet.' Can you imagine such a 

 thing a mile or two miles in depth?" 



