280
TIMBER AND TIMBER TREES.
[CHAP.
We are thus enabled to compare the strength of the earlier and the later growth of this wood.
Number of the the specimen. |
Deflections. | Total weight required to break each piece | Specific gravity. | Weight required to specific gravity 600. |
Weight required to break 1 square in. |
Tensile Experiments. | |||||
With the apparatus weighing 390 lbs. |
After the weight was removed. |
At the crisis of breaking. |
Direct cohesion on 1 square in. |
Number of the specimen. | |||||||
Inches. | Inches. | Inches. | lbs. | lbs. | lbs. | ||||||
7. | 3' | 1.500 | .500 | 4.250 | 508.00 | 568 | 537 | 127.00 | 2660 | 3. | 22 |
8. | 2' | 1.250 | .500 | 4.250 | 562.00 | 600 | 562 | 140.50 | 2800 | 2. | 23 |
9. | 1' | 1.500 | .500 | 2.250 | 480.00 | 537 | 536 | 120.00 | 2485 | 1. | 24 |
10. | ʘ | 2.250 | 1.100 | 2.750 | 360.00 | 430 | 502 | 90.00 | ʘ | ||
11. | 1′ | 1.850 | .850 | 3.000 | 480.00 | 588 | 490 | 120.00 | 2730 | 1′ | 25 |
12. | 2′ | 1.900 | .900 | 4.250 | 512.00 | 568 | 541 | 128.00 | 2800 | 2′. | 26 |
13. | 3′ | 1.750 | .650 | 3.000 | 478.00 | 566 | 507 | 119.50 | 3080 | 3. | 27 |
Total | 12.000 | 5.000 | 23.750 | 3,380.00 | 3857 | 3675 | 845.00 | 16,555 | — | ||
Aver. | 1.714 | .714 | 3.393 | 482.85 | 551 | 525 | 120.71 | 2759 | — |
The mean results of the experiments are as follows, viz. :—
The centre piece | ʘ | s.g. | 430 | broke with | 360 | lbs. | E = 785170. S = 945 |
The„ next pieces | 1 and 1 | s.g.„ | 562 | broke with„ | 480 | lbs„ | E = 902950. S = 1261 |
The„ next pieces | 2 and„ 2′ | s.g.„ | 584 | broke with„ | 537 | lbs„ | E = 577020. S = 1425 |
The„ outer pieces„ | 3 and„ 3′ | s.g.„ | 567 | broke with„ | 493 | lbs„ | E = 822740. S = 1294 |
The mean of the 7 pieces being E = 902950 and S = 1267.
In the above example, there is something like a