122 Trenton Limestone of Minneapolis and St. Paul — Hall. 



which seriously injure it for any building purposes, have already 

 been alluded to. (p. 114.) 



Several cubes vi^ere prepared and submitted to Professor W. 

 A. Pike, of the State University, for a test of crushing strength. 

 The samples from the middle of the building stone layer gave, as 

 an average of several tests, a resistance on bed of 6,250 pounds 

 per square inch. Several tests were made with the stone at right 

 angles to bed, but the results were not satisfactory; no more than 

 the jar produced by the hammer in dressing hand specimens is 

 sufficient to separate the bands of aluminous from those of 

 calcareous material. 



The lowest part of this layer, that lying directly above the 

 contact with the green shaly sandstone (see Fig. 2, p. 117) and 

 also (Plate I, Fig. 2) is considerably stronger than that in the mid- 

 dle and upper portions of the same layer. This showed a resis- 

 tance on bed of 10,312 pounds, and on edge of 8,112 pounds 

 per square inch. These tests show that the lowest portion of 

 the bed is much stronger than the middle: and a mere inspec- 

 tion of the material will show that the middle layers are much 

 stronger than the upper ones. 



A Note on" the Borings of the West Hotel Artesiak 

 Well. — The boring of the artesian well at the West Hotel in this 

 city a short time ago was followed with considerable interest. Mr. 

 E. J. Swan, who did the work, kindly furnished the writer with a 

 carefully preserved set of borings, the numbers and descriptions of 

 which may be summarized as follows: 



1. tSoil, gravel, sand and clay, thickness 34 feet 



2. Limestone and shale (Trenton) 20 " 



:}. First waterbearing stratum. The St.Peter sandstones and shale8,164 " 



4, Magnesian limestone 114 " 



f). Sandstone with some alternating layers of shale. Second 



waterbearing stratum 100 " 



(J. Shales ])lue and green with some sandstone layers interca- 

 lated 163 ^ 



7. White sandstone. Third and abundant ilow of water 23 " 



Total depth 018 " 



The foregoing figures show the thickness of the glacial drift 

 and overlying soil to be 34 feet, the Lower Silurian 20 feet and the 

 Cambrian penetrated through 564 feet of its thickness. The bor- 

 ings also agree very closely with those from the well bored at the 

 Washburn ^^C" by Mr. C. C. Whelpley. These borings belong to 



