Page:Timber and Timber Trees, Native and Foreign.djvu/174

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154
TIMBER AND TIMBER TREES.
[CHAP.

strain, or by a crushing force in the direction of its fibres. Tried by the latter process, it exhibits a peculiarity unshared, I believe, by any other timber except Sabicu. It bears the addition of weight after weight without showing any signs of yielding; and, when the crushing force is obtained, it gives way suddenly and completely, with a loud report, nothing being left of the pieces but a loose mass of shapeless fibres.

The Greenheart timber is not usually hewn in the perfect manner that Teak, Mahogany, and many other woods are when prepared for shipment to the markets of this country, but comes from Demerara only partially dressed, a great deal of wane being left upon the angles. The butts are also almost invariably left with the snapped ends, as prepared for drawing out of the forest, instead of being cut off square. Its form should therefore be considered with the price quoted per load, as it will not compare favourably with well-squared timber.

Table LXXIII.— Greenheart (Demerara).
Transverse Experiments.
Number
of the
specimen.
Deflections. Total
weight
required
to break
each
piece.
Specific
gravity.
Weight
reduced
to
specific
gravity
1000.
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 2.15 .050 5.000 1.235.0 1180.0 1047.0 308.750
2 2.00 .000 4750 1,656.0 1193.0 1388.0 414.000
3 2.25 .150 4.600 1,305.0 1079.0 1209.0 326.250
4 2.00 .00.0 5.000 1,212.0 1152.0 1052.0 303.000
5 2.25 .150 44.150 1,258.0 1172.0 1073.0 314.500
6 2.25 .050 4.250 1,329.0 1122.0 1184.0 332.250
Total 12.90 .400 27.750 7,995.0 6898.0 6953.0 1998.750
Average 2.15 .066 4.625 1,332.5 1149.6 1158.8 333.125

Remarks.—Nos. 1, 2, 3, and 6 broke with splintery fractures, 12 to 15 inches in length; 4 and 5 with similar fractures, but only 10 to 12 inches in length.