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COMPRESSIVE STRENGTH OF VARIOUS MATERIALS.
TEST NO. 12.
This test was similar to test No. 8 except that the cylinder filled with the culm was allowed to stand, with the piston removed, for eight days over a boiler. The culm was 9 inches deep in the cylinder, and the pressure was applied to the piston until the settlement reached 3 inches under a load of 300,000 pounds. This load corresponds to a pressure of 9,200 pounds per square inch. Although the culm had been drying for eight days, there was considerable water in it; the water was squeezed out during the test. The loads and settlements for this test follow.
Loads and settlements of damp culm confined in a cast-iron cylinder.
Loads.	Settle- ments.	Loads.	Settle- ments.	Loads.	Settle- ments.
Pounds.	Inches.	Pounds.	Inches.	Pounds.	
500		20,000	1.216	150,000	2.631
1,000	0.057	30,000	1.501	200,000	2.762
2,000	.175	40,000	1.708	250,000	2.876
5,000	.452	50,000	1.871	300,000	2.999
10,000	.786	75,000	2.168		
15,000	1.025	100,000	2.373		
TEST NO. 13.
This test was exactly similar to test No. 8, except that the cast-iron cylinder was filled with dry Delaware River sand; the sand was placed in the cylinder and settled by shaking until it was flush with the top. The load was then applied to the piston until a maximum pressure of 300,000 pounds, with a corresponding settlement of 3.4 inches, was reached. The table showing loads and settlements follows.
Loads and settlements of dry Delaware River sand confined in a cast-iron cylinder.
Loads.	Settle- ments.	Loads.	Settle- ments.	Loads.	Settle- ments.
Pounds. 100 500 1,000 2,000 5,000 10,000 15,000	Inches. 0.13 .25 .41 .65 .89 1.07	Pounds. 20,000 30.000 40.000 50.000 75.000 100,000 125,000	Inches. 1.22 1.46 1.66 ' 1.83 2.15 2.39 2.59	Pounds. 150.000 175.000 200.000 250.000 300.000	Inches. 2.75 2.89 3.01 3.20 3.35
TEST NO. 10.
This test consisted in applying pressure to the piston of the cylinder in the same manner as in test No. 9; the broken sandstone had 40 per cent voids; the pieces would all pass through a ring If inches in diameter, and all voids were filled with river sand. The cylinder was filled to the top, giving the mixture of stone and sand a depth of 10tj inches. The maximum load applied was 300,000 pounds, or 9,200 pounds per square inch, which corresponded to a settlement of 2.4 inches. As a result of the test the stone was completely crushed and compacted in the iron cylinder. Loads and settlements for the test follow.