66 THE GRANITES OF MAINE. 
Freezing and thawing. — Buckley's method consists in drying . 
1-inch and 2-inch cubes at a temperature of 110° C. and weighing 
them. After being saturated in distilled water they were exposed 
overnight to a temperature below freezing. They Avere then thawed 
out and soaked in warm distilled water. This process was continued 
for thirty-five days, when they were again dried at 110° C. and 
weighed. Finally the same stones were subjected to the tests for com- 
pressive strength and the results compared with those for stones not 
thus treated. 
Absorption and compression. — The complete saturation of a stone 
and the determination of the amount of absorption are effected by a 
method described at length by Buckley. 6 The saturated stone should 
then be tested f or compressi ve strength and the result compared with 
that obtained from (\vy stone. 
Behavior under fire. — This test is best applied to saturated speci- 
mens, which are then exposed in a laboratory furnace to a tempera- 
ture up to 1,500° I\ and the effect noted. Some of them can be 
allowed to cool gradually, but others should be immersed quickly in 
cold water; or they may be exposed to high temperature while under 
compression. and then cooled -lowly or quickly. c 
Specific gravity. — The specific gravity is the weight of the stone 
at 16° C. compared with that of the same volume of distilled water 
at 4° C. All air should first be removed from the piece to be tested 
by boiling in distilled water. The specific gravity is also required 
for the test of porosity. 
Weight per cubic foot. — The weight of the i\vy stone per cubic 
foot is obtained by multiplying its specific gravity by the weight of 
a cubic foot of water, but from this there should be deducted u the 
weight of a quantity of stone of the same specific gravity equal in 
volume to the percentage of the pore -pace in the stone." d This 
gives the actual weight of the stone I'va* from interstitial water. 
Coefficient of expansion. Finally, it may be desirable to obtain 
the coefficient of expansion of a granite intended for some particular 
construction. The expansion of certain granites was determined at 
the Watertown Arsenal by hot and cold water baths. The stones 
thus tested were afterward- subjected to the test for transverse 
strength, when it was found that they had lost 16.93 per cent of their 
original strength. 6 
A list of the various tests applied to building stones by German 
testing institutions is given by Herrmann/ 
a Buckley, op, cit., p. 71. 
b Buckley, op. cit., pp. 64-67. 
c Buckley, op. cit., pp. 73, 411. 
A Buckley, op. cit.. p. 70. 
c Rept. of tests of metal, etc.. ]». 320. 
f Steinbruchindustrie uud Steinbrucbgeologie, p. 10 et seq. 
