shows at a glance the behavior, strength, elasticity, etc., of the 

 material tested. 



DETAILS OF TRANSVERSE STRESS TESTS. 



(I.) Carbon. 28-inch supports. Green sample from the sap, 

 .and with a few small knots on top. Like the other, it broke 

 just after having brought the beam up by its elastic resistance, 

 under 650 pounds, and deflected roil inches. Remained un- 

 broken. 



(2.) . 25-inch supports. A very well seasoned 



piece, but slightly weakened by a knot where it first gave way. 

 The first rupture occurred at 950 pounds on the weak part. The 

 second under 1,150 pounds with a long and several other small 

 splinters on tension side. Total deflection, 1-687 inches. 



(3.) Chaperno. 24-inch. A very good sample as regards 

 soundness and seasoning. Cross grained. Broke under 3,700 

 pounds, with a deflection of 0-496 inch. Broke gradually in small 

 splinters from the bottom side upwards, and crushed slightly 

 on top also. 



(5.) Cortez. 24-inch. A large sample from near the 

 heart. Excepting two knots on thickness and bottom sides 

 respectively, and checked on sap line on top, it was a fine sample. 

 Its toughness is shown by its behavior under load. Reached the 

 elastic limit at 2,500 pounds, broke at 4,300 pounds, with a defle. - 

 ' tion of O 443 inch. Second rupture occurred under 4,650, with a 

 deflection of 1-3975 inch. By diminishing the loads it might have 

 given more ruptures without breaking completely. Broke in 

 several adhering splinters on tension side. 



(7.) Guachipilin.' ii-inch supports. Good sample. Tbe 

 first rupture occurred under 1,800 pounds load with 0-462 inch 

 deflection. After the first rupture it showed a good deal of 

 elasticity in resisting the loads and gradually ruptured slightly 

 under 2,050 pounds. The reason we took this latter for the 

 rupturing load is on account of the behavior after the first rupture, 

 which latter was very light, and on account of a weak point. 

 Both ruptures were very light splinters, and the piece might have 

 shown still more tenacity if the load had been diminished. But 

 here, as in most cases, we were after first rupture only. Almost 

 any kind of wood will behave in the same way if so treated, unless 

 it is very brittle. 



