220
TIMBER AND TIMBER TREES.
[CHAP.
As Elm timber is best and most durable when worked up soon after the tree is felled, it is not necessary to keep in store more than is required from year to year. If, however, it should be thought desirable to accumulate stock with the view to provide against emergencies, it will be most effectually preserved for future use by keeping it constantly under water, or burying it in mud.
Table CXIV., showing the transverse strength of this wood, is not so full or satisfactory as could be desired, owing to the difficulty experienced in finding pieces sufficiently straight in the grain for experimental purposes. The Tables CXV. and CXVI., showing the tensile and vertical strength, are, however, more reliable.
Number of the specimen. |
Deflections. | Total weight required to break each piece. |
Specific gravity. |
Weight reduced to specific gravity 700. |
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 | ... | ... | 3.500 | ... | 578 | ... | ... |
2 | 5.25 | 1.25 | 7.500 | 510 | 571 | 625 | 127.5 |
3 | ... | ... | 6.250 | ... | 558 | ... | ... |
4 | ... | ... | 4.000 | ... | 553 | ... | ... |
5 | 475 | 1.30 | 5.500 | 350 | 545 | 450 | 87.5 |
6 | 4.70 | 1.35 | 5.000 | 320 | 542 | 413 | 80.0 |
Total | 14.70 | 3.90 | 31.750 | 1,180 | 3347 | 1488 | 295.00 |
Average | 4.90 | 1.30 | 5.291 | 393 | 558 | 496 | 98.33 |