Page:Timber and Timber Trees, Native and Foreign.djvu/311

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Specimens 19 to 24, with the early layers, also 25 to 30, with the later layers of wood, were taken from a log of the same dimensions as the last, and under precisely the same conditions as those referred to in Tables CLIV. and CLV., the results being nearly as before; that is, specimen 20, or the second piece from the butt-end of the early growth, and specimen 25, or the butt length of the later growth, are the two strongest pieces of the respective series. We also see in the mean results of the experiments that the strength of the inner is to the outer wood as 733 1755. Thus the outside is as before, the strongest.

The mean of Tables CLIII. and CLVL, with early layers or inner wood,
E= 711945. S=2130.
The mean of Tables CLV. and CLVII., with later layers or outer wood,
E=763800.S=2264.

Table CLVIII.
Tensile Experiments.

Number of the specimen.	Dimensions of each piece.			Specific gravity.	Weight the pieces broke with.	Direct cohesion on 1 square inch.
	Inches.				lbs.	lbs.
31	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right\}\,}$	2 × 2 × 30	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	693	16,800	4,200
32				630	17,640	4,410
33				651	19,320	4,830
34				620	17,920	4,480
35				662	19,600	4,900
36				698	20,720	5,180
Total.	...			3954	112,000	28,000
Average	...			659	18,666	4,666

 

Table CLIX.
Vertical or Crushing Strain on cubes of 2 inches.

No. 37.	No. 38.	No. 39.	No. 40.	No. 41.	No. 42.	Total.	Average.	Ditto on 1 square inch.
Tons.	Tons.	Tons.	Tons.	Tons.	Tons.	Tons.	Tons.
10.875	111.25	11.5	11.625	12.00	12.125	69.25	11.542	2.885