222 MR. W. FAIEBAIEN AND MB. T. TATE ON THE JIECHANICAL PEOPEEIIES 
as to retain the first-cooled exterior skin of glass, which f 
than the interior; on the other hand, the cubes were cut from the centre of larger 
lumps of glass, and were possibly rn a state of rmperfect annealrng. 
Flint-glass Cubes. 
Experiment 12. 
„0-96 X 0-97 inch =0-9312 square inch. 
Heieht =1-15 inch. 
Crushed suddenly with 13,257 lbs.=14, 235 lbs. per square 
inch. 
Experiment 13. 
Area =0-99 X 0-98 inch=0-9702 square inch. 
Height =1-16 inch. 
Crushed with 12,809 lbs. =13,202 lbs. per square mch. 
Experiment 14. 
^0-98 X 1-02 inch=0-9996 square inch. 
Height =1-10 inch. _ 
Crushed with 13,257 lbs.=13,262 lbs. per square rnch. 
Experiment 15. 
Area =0-98mchx0-98in.=0-9604 square inch. 
Height =1-10 inch. 
Fractured with 6537 lbs. = 6806 lbs. per square rnch. 
Crushed with 11,353 lbs.=ll,820 lbs. per square rnch. 
Gveen Glass Cubes. 
Experiment 16. 
Area =1-0 X 0-98 inch=0-98 square inch. 
Height =10 inch. 
Crushed with 20,059 lbs.=20,468 lbs. per square inch. 
Experiment 17. 
Area =0-99 x 1-2 inch=l-188 square inch. 
Height =1-0 inch. . 
Crushed with 23,635 lbs. =19,915 lbs. per square rnch. 
