170 SPARKS FROM A GEOLOGIST'S HAMMER. 



In the Mississippi valley we have some evidence of the 

 existence of man while yet Illinois was flooded by the high 

 waters of Lake Michigan. I had in my possession for 

 some time a copper relic resembling a rude coin, which 

 was taken from an artesian boring at the depth of 114 

 feet at Lawn Ridge, Marshall county, Illinois. Mr. W. H. 

 Wilmot, then of Lawn Ridge, furnished me, in a letter 

 dated December 4, 1871, the following statement of de- 

 posits pierced in the boring: 



Soil, 3 feet. 



Yellow clay, 17 " 



Blue clay, 44 " 



Dark vegetable matter, 4 " 



Hard purplish clay, 18 " 



Bright green clay, 8 



Mottled clay, 18 " 



Soil, 2 " 



Depth of coin, 114 " 

 Yellow clay, 1 " 



Sand and clay, 

 Water, rising 60 feet. 



In a letter of the 27th of December, written from Chil- 

 licothe, Illinois, he stated that the bore was four inches 

 for eighty feet, and three inches for the remainder of the 

 depth. But before one hundred feet had been reached the 

 four-inch portion was " so plastered over as to be itself 

 but three inches in diameter," and hence the " coin " could 

 not have come from any depth less than eighty feet. 



most eminent scientific authorities'" (Meth. Quar. Rev., April 1881, p. 228). One 

 cannot help wondering what sort of evidence would convince Mr. James C. 

 Southall. 



