wood for the converter to deal with, the instances of defects being found in opening it, arising either from pruning or from accidental causes, being extremely rare.
About 2,500 to 3,000 loads of this wood are imported annually into each of the London and Liverpool markets, to meet the wants of private dealers, who employ it for coach-making, turnery, boat-building, &c. The Government also take about 600 to 700 loads annually for the use of the royal dockyards, stipulating in their contracts that it shall be of the first quality, from 11 to 15 inches square, averaging 12½ inches; 20 feet and upwards in length, averaging at least 24 feet in length, and to be well squared, and free from knots.
The Canada Rock Elm is a remarkably slow-growing tree, the slowest in fact with which we have to deal; it makes only one inch of wood diameter in about fourteen years.[1]
| Number of the 1 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. | Inch. | Inches. | lbs. | lbs. | |||
| 1 | 1.60 | .25 | 8.55 | 935 | 760 | 86l | 233.75 |
| 2 | 1.85 | .30 | 8.75 | 946 | 753 | 893 | 236.50 |
| 3 | 1.75 | .30 | 9.00 | 899 | 735 | 856 | 224.75 |
| 4 | 1.90 | .35 | 8.65 | 918 | 740 | 868 | 229.50 |
| 5 | 1.85 | .25 | 875 | 927 | 738 | 879 | 231.75 |
| 6 | 1.55 | .30 | 9.05 | 895 | 765 | 819 | 223.75 |
| Total | 10.50 | 1.75 | 52.75 | 5,520 | 4491 | 5176 | 1380.00 |
| Average | 1.75 | .29 | 8.79 | 920 | 748 | 863 | 230.00 |
Remarks.—All fractured and crippled, but not completely broken asunder.
- ↑ See Tabular Statement in Chapter II., on the comparative rate of growth of trees, p. 18.
