XXXIV.]
YELLOW PINE.
279
| Number of the specimen. |
Deflections. | Total weight required to break each piece. |
Specific gravity. |
Weight reduced to specific gravity 600. |
Weight required to break 1 square inch. | ||
| With the apparatus weighing 390 lbs. |
After the weight was removed. |
At the crisis of breaking. | |||||
| Inches. | Inches. | Inches. | lbs. | lbs. | |||
| 1 | 2.000 | 1.750 | 4.50 | 630.0 | 424 | 891 | 157.50 |
| 2 | 2.000 | 1.650 | 5.00 | 636.0 | 432 | 882 | 159.00 |
| 3 | 2.000 | 1.850 | 4.50 | 684.0 | 464 | 884 | 171.00 |
| 4 | 1.750 | 1.650 | 4.50 | 660.0 | 444 | 892 | 165.00 |
| 5 | 2.250 | 2.000 | 3.75 | 552.0 | 435 | 761 | 138.00 |
| 6 | 2.750 | 2.100 | 5.75 | 598.0 | 411 | 873 | 149.50 |
| Total | 12.75 | 11.00 | 28.00 | 3760 | 2610 | 5183 | 940.00 |
| Average | 2.125 | 1.833 | 4.66 | 626.6 | 435 | 864 | 156.66 |
Remarks.—The whole of these broke with a moderate length of fracture and splintery.
The above-mentioned specimens were all of good quality, well seasoned, and taken from trees of 6 to 8 feet in circumference. It will be observed that the specific gravity and breaking strains varied only in a slight degree. By the formulæ—
E = 309240.S = 1645.
Experiments were also made to test the transverse strength of a series of seven pieces (Table CXLIX.) cut from a plank 2 inches thick, taken out of the middle or centre part of the butt-end of a tree, the centre piece ʘ being made to include the pith (Fig. 30).
FIG. 30.
