Page:Timber and Timber Trees, Native and Foreign.djvu/141

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XX.]
INDIAN TEAK.
121

test the deflections of Teak under given weights at various distances, viz.:—

Table XLIV.
Nos. 1 to 6.
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