Studies for Students 



RESULTS OF TESTS OF WISCONSIN BUILDING 

 STONE III < 



In this the concluding paper on the testing of building 

 stones I will summarize and discuss various tests which I made 

 in the laboratory of the Wisconsin Geological Survey during the 

 winter of 1897-8. 



In examining the tests recorded in some of the reports 

 on building stones I found them to be really of little value, 

 either on account of the failure of the operator to describe care- 

 fully the methods employed in making the tests or owing to 

 insufficient care in manipulation and computation. It has been 

 noted that among sedimentary rocks the results of tests on sam- 

 ples from different parts of the same quarry may be very differ- 

 ent. Such differences may be even more marked than those that 

 occur between samples from different quarries within the same 

 area. It is possible to select samples from a quarry which will 

 give very high tests, while a greater part of the stone may be of 

 the poorest kind. Valuable results can only be obtained when 

 tests are made upon samples which are a fair average of the 

 stone as it occurs in the quarry. 



For making the tests herein discussed, the author endeavored 

 to obtain samples which represented as nearly as possible aver- 

 age No. 1 stone. The tests were performed as nearly as possible 

 in accordance with the instructions laid down in the previous 

 paper. The utmost care was exercised in obtaining truthful 

 results, and it is believed that the figures given are nearly accu- 

 rate for the samples tested. 



1 The illustrations accompanying this paper are used by permission of the director 

 of the Wisconsin Geological and Natural History Survey. A fuller discussion of 

 these tests will be found in Bulletin No. IV of the Wisconsin Geological and Natural 

 History Survey reports. 



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