Page:Timber and Timber Trees, Native and Foreign.djvu/309

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Table CLV.—Pitch Pine (American).
Transverse Experiments.—3rd Example.
(Butt to top, outer part of the tree. Fig. 32b.)

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.
13	1.150	.0000	3.750	1035	840	740	258.75
14	1.150	.1500	2.750	985	788	725	221.25
15	1.000	.0000	5.000	1,110	760	876	277.50
16	1.250	.1500	3.750	920	655	843	230.00
17	1.250	.0000	4.750	925	613	905	231.25
18	1.350	.2000	4.750	845	610	831	211.25
Total	7.150	.5000	24.750	5,820	4266	4920	1430.00
Average	1.191	.0833	4.125	970	711	820	238.33

Remarks.—No. 13 broke short and split; 14, curl in the grain and broke short; 15 and 16 broke short and split; 17 and 18 broke with short fracture.

E = 815070. S = 2546.

Specimens Nos. 13 to 18, with the later layers or growth, were taken from the outside of the same plank, the object being to ascertain in the two sets of experiments—Tables CLIV. and CLV.—in which part of the length the maximum of strength lay. Table CLIV. shows that in the early layers it is in specimen 8, the second piece from the butt-end; and Table CLV. shows that in the wood of later growth it is in specimen 15, the third piece from the butt-end. We also see in the mean results of the experiments that the strength of the inner is to the outer wood as 889 :970.

Further experiments on the transverse strength of the inner and outer layers of wood of another Pitch Pine tree were then carried out, with the following results :—