Number of beam.Top or butt of log.bhILoads:S = Plc/4Id, Inches.EWeight, in pounds per cubic foot.Remarks.
Width, in inches.Height, in inches.I = bh3/12Actual at elastic limit.Maximum.At elastic limit.Maximum.At elastic limit.E = Pl3/48dI
I B 6.28 15.94 2,120 22,000 45,900 2,975 6,2000.411,575,000 50.2 Close-grained pine, long-leaf.
I T 6.00 15.69 1,934 20,000 38,000 2,915 5,5400.4651,383,000 47.5
II[A] T 6.37 15.81 2,098 20,000 43,450 2,722 5,918 0.3801,562,000 40.5 Coarse loblolly, large knots.
II B 6.41 16.41 2,360 16,000 25,040 1,999 3,130 0.430 979,000 42.2
IIIT 5.88 15.68 1,871 24,000 45,130 3,608 6,785 0.5351,489,000 40.4 Close-grained, long-leaf no knots.
III B 5.88 15.90 1,965 21,000 35,190 3,054 5,120 0.5151,288,000 44.2
IV T 6.00 15.43 1,835 22,000 38,425 3,320 5,810 0.4651,601,000 40.8 Loblolly, with knots.
IV B 6.12 15.87 2,032 22,000 35,500 3,090 4,983 0.6601,017,000 41.5
V B 6.00 16.00 2,048 22,000 47,000 3,090 6,610 0.4001,670,000 47.2 Long-leaf yellow pine.
V[A] T 6.00 15.87 1,999 14,000 22,050 1,998 3,145 0.3151,382,000 42.1
VI[A] B 5.50 15.75 1,790 22,000 51,330 3,484 8,925 0.4501,695,000 50.2 Long-leaf yellow pine.
VI[A] T 5.87 15.62 1,865 20,000 44,000 3,013 6,627 0.4101,625,000 45.2
VII B 6.56 15.62 2,083 34,000 51,900 4,580 6,985 0.6201,637,000 43.7 Long-leaf yellow pine.
VII[A] T 6.22 15.62 1,975 20,000 49,000 2,845 6,970 0.3801,658,000 40.2

[A] Failed in longitudinal shear.

The deflection was measured on both sides of each beam by using silk threads stretched on each side from nails driven about 2 in. above the bottom of the beam and directly over the rollers which formed the supports. From a small piece of wood, tacked to the bottom of the beam at its center and projecting at the sides, the distance to these threads was measured. These measurements were taken to the nearest hundredth of an inch. The mean of the deflections was taken as the true deflection for any load.

Fig. 3.—DEFLECTON CURVES BEAM III

Fig. 4.—DEFLECTON CURVES BEAM IV

In computing the various quantities shown in Table 1, the summary of results, the load has been assumed as concentrated at the center of the beam. While it is true that the load was spread over a length of about 12 in., due to the width of the head of the machine and the plate between it and the beam tested, it is also true that there were irregularities, such as bolt-holes and, in some cases, abrasions due to wear, that could not well be taken into account. Hence, it was deemed sufficiently accurate to consider the load as concentrated. Besides the horizontal bolt-holes, shown in the photographs, there were vertical bolt-holes, at intervals in all the beams. The latter were 7/8 in. in diameter, and in every case they were sufficiently removed from the center of the length of the beam to allow the maximum moment at the reduced section to be relatively less than that at the center of the beam. For this reason, no correction was made for these holes. The broken beams often showed that rupture started at, or was influenced by, some of the holes, especially the horizontal ones.

While some of the heavy oils of a tarry consistency remained, they were only to be found in the sappy portions of the long-leaf pine and in the loblolly (Specimens II and IV). Exposure in a semi-tropical climate for 26 years had resulted in the removal of the more volatile portions of the creosote oil. The penetration of the oil into the sap wood seemed to be perfect, while in the loblolly it varied from a fraction of an inch to 1-1/2 in. In the heart wood there was very little penetration across the grain. The timber had been framed and the holes bored before treatment. The penetration of the creosote along the grain from the holes was often from 4 to 6 in.