25 



the first time. However, it still reached about twice as large a 

 moment which kept constant till final rupture. Fibrous and tough 

 rapture. 



(24.) Piedra (Stone), d = 0-6257. A piece turned from near 

 the heart and very sound. It rose with a parabolic short wavy line 

 up to the elastic limit, when it had a moment of 227 inch-pounds 

 at an angle of 9 0> 7 It reached a maximum moment of 228-7 inch- 

 pounds at an angle of 11, and very soon lowered its moment to 

 221-8 inch-pounds, which kept constant until it splintered at 50. 

 Wide splinters and stiff rupture, but square around the shoulders. 

 (26.) Quiebra-hacha. d =06268. A very sound piece. It 

 rose with a parabolic curve above 45, with the axis of strains up 

 to 1 66 inch-pounds moment, its elastic limit, and kept reaching 

 higher and higher moments by regular intervals up to a maximum 

 after first rupture of 319-479 inch-pounds without giving way com- 

 pletely. Brushy, regular break and very tough. 



(29.) Ron-ran Dry and sound piece. Rose with a straight line 

 up to 82-26 inch-pounds moment at an angle of i-5, and kept a 

 constant moment till final rupture. Broke with brittle fracture in 

 two pieces, without showing any fibre. 



(32.) Zapotillo. The test-piece turned from a large sample, 

 d = 0-6258 inch; had a small knot on one end, but very sound 

 otherwise. It reached its maximum at the elastic limit at an angle 

 of 5 0< 5 from the origin, rupturing with the same moment at angle 

 of 9. It kept a constant moment for about 80, when it reached 

 a little higher moment holding it till final rupture. Fibrous 

 rupture. 



(33.) Zopilote. At first rose with a straight line below 45, and 

 turned parabolic near and after the elastic limit. First ruptured at 

 28 angle under a 106 inch-pounds moment and raised it slightly, 

 keeping the latter constant for over 160. A very thready and 

 tough rupture. 



