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STATE GEOLOGIST. HPAL 
kennel which is comfortable, durable and easily kept in sanitary condition. 
At his stable, he has constructed a concrete stove on which to cook the 
food for his stock. In all this work he has used woven wire netting with 
a concrete of I cement, 2 sand and 5 cinders. 
Fig. 65.—Concrete Burial Vault. 
COEFFICIENT OF EXPANSION OF CONCRETE. 
tT From 1899 to 1901, Prof. Wm. D. Pence, of the Purdue University, 
Lafayette, Ind., with several of his students, carried on a series of tests to 
determine the coefficient of expansion for concrete. It was planned with 
special reference to the use of steel with concrete. The composition of 
the concrete was based upon the specifications of Mr. Edwin Thacher, M. 
Am. Soc. C. E., for a concrete for use in concrete steel construction: 
namely, I part cement, 2 parts sand and 4 parts crushed stone that will 
pass through a 1% inch ring. Lehigh Portland cement was used the first 
year and Medusa Portland the second. In the first series of tests Bedford 
oolitic limestone was used and in the second, Kankakee, Illinois, limestone 
was used. A bar of unbroken limestone was also tested in the second 
series. 
“In the plan finally adopted a standard bar of steel or copper with 
known coefficient of expansion was subjected to identical changes of 
temperature with the test bar of concrete, and the difference of expansion 
of the two bars was determined by the principle of the ‘optical lever.’ 
This difference in length, reduced to a unit of length and temperature, 
gave a correction to be applied to the known coefficient of the metal bar.” 
+‘‘Hng. Record, Feb’y. 22, 1902.’’ 
