XX.]
INDIAN TEAK.
121
test the deflections of Teak under given weights at various distances, viz.:—
Specimen, 2 x 2 X 84 inches, supported on props, | 3 ft., | 4 ft., | 5 ft., | 6 ft. apart. | |
Weighted with 300lbs., the deflections were | .065 | .300 | .750 | 1.250 | ins. |
Weighted„ with„ 400lbs., the deflections„ were„ | .300 | .600 | 1.150 | 2.050 | ins.„ |
Specimen, 2 deep × 1½ broad × 84 inches, supported on props, |
3 ft., | 4 ft., | 5 ft., | 6 ft. apart. | |
Weighted with 300lbs., the deflections were | .300 | .400 | 1.100 | 2.100 | ins. |
Weighted„ with„ 400lbs., the deflections„ were„ | .400 | .800 | 1.500 | 2.800 | ins. |
This piece, tried the other way, viz.:—
1½″ deep × 2″ broad, supported on props, | 3 ft., | 4 ft., | 5 ft., | 6 ft. apart. | |
Weighted with 300lbs., the deflections were | .200 | .800 | 1.600 | 3.200 | ins. |
Weighted„ with„ 400lbs., the deflections„ were„ | 500 | 1.200 | 2.600 | Broke. |
The specific gravity of these pieces was respectively .586 and .631.; a proof that they were thoroughly seasoned. Upon the laws which govern these deflections, I offer no opinion, and the experiments are merely introduced here to show how near the results go to confirm Professor Barlow's theory that the strength varies as the cubes of the length.
There is one other species of trial which it may be well to mention, namely, that to ascertain the elongation