Page:Timber and Timber Trees, Native and Foreign.djvu/318

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298
TIMBER AND TIMBER TREES.
[CHAP.

considered one of the best woods for working that the carpenter can take in hand.

There are many experiments on the strength of the Kauri Pine, and the first to be noticed are on specimens
FIG. 33.
taken from the butt-end of a log that was fully 60 feet in length and 22 inches square. A plank 2 inches thick having been taken out of the middle, it was cut to produce six pieces of 2 × 2 × 84 inches, four upon one side of the centre or pith and two upon the other (Fig. 33). The centre piece was excluded from the test as being of too weak a nature to bear comparison with the rest of the wood.

Table CLX.—Kauri (New Zealand).
Transverse Experiments.
Number
of the
specimen.
Deflections. Total
weight
required
to break
each
piece.
Specific
gravity.
Weight
reduced
to
specific
gravity
600.
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 d 1.25 .00 3.75 818 525 934 131.25
2 c 1.25 .15 4.25 875 529 992 132.25
3 b 1.15 .10 4.20 820 529 930 132.25
4 a 1.05 .00 3.75 750 520 865 130.00
5 a 1.15 .10 3.40 760 515 885 128.75
6 b 1.50 .15 4.15 870 562 929 140.50
Total 7.350 .500 23.500 4893.0 3180 5535 795.00
Average 1.225 .083 3.916 815.5 530 917 132.50

Remarks.—These specimens broke with a moderate length of fracture.

E = 790810. S = 2141.

The table shows that transversely the strongest point was much nearer to the more recently-formed con-