(5) The greatest care should be observed in avoiding obliqueness of 

 grain in columns, as the effective bearing area, and therefore also the 

 strength, are considerably diminished. 



(6) If the end bearings are not perfectly flat and parallel, the 

 columns will in all probability fail by bending concave to the longest 

 side. 



(7) The average strength per square inch, independent of the ratio 

 of length to diameter, is: 



5974 Ibs. for New Douglas Fir 



6265 " for Old " " 



4067 " for New Red Pine 



3843 " for New White Pine 



2772 " for Old " 



3617 " for New Spruce (B.C.) 



5136 " Old Spruce 



It should be pointed out that none of the old Douglas Fir columns 

 exceeded 4.4 diameters in length, while the great majority of the new 

 Douglas Fir columns were from 4 to 25 diameters in length. This 

 explains the reason of the greater average comprcssive strength of the 

 old Douglas Fir. A similar remark applies to the New and Old Spruce. 

 Table giving in detail the results of the experiments on the different 

 specimens : 



KKSULTS OF COMPRESSION TESTS ON 



NEW DOUGLAS FIR. 



^ .3 



50_o ^ . 



Dimensions in in-. ^ -"& - ~2 



Lengths. g'~ "~ -= i? Remarks. 



.3 ~ j - 



3.07 X 3.08 X 3.11 6367 Falie(i b > bulging. 



3.06 X 3.08 X 3.10 5760 Failed by folding. 



2.63 X 3.63 X 5.S1 4923 30.3 Specimen 3" or 4" from 



heart ; grain straight ; 

 one small knot on high 

 edge. Failed by crippling 

 at knot on high edge. 



3.65 X 3.65 X 6.12 3678 29.8 Heart piece; grain 



straight but seasoned ; 

 annular rings very wide; 

 two knots, one on high 

 edge. Failed at this lat- 

 ter by crippling. 



2.19 X 3.74 X 5.40 -'"ei 38.4 Straight grained ; one 



large knot from side to 

 side-, specimen 3" or 4" 

 away from centre. Fai led 

 at knot. 



4.10 X 4.30 X 8.05 5218 32.9 Large knot on one end ; 



many small knots all 

 through piece ; also 

 heavy season cracks. 

 Failed by bursting along 

 season cracks and 

 through knots. 



2.15 X 2.25 X 9.2 5809 38.8 All clear. Failed by 



crippling. 



2.17 X 2.25 X 9.14 7313 35.1 s ?"d, clear and 



straight grained; small 

 deficiency on one side at 

 end. Failed bv crip- 

 pling. 



2.12 X 2.16 X 9.15 7294 38.7 Straight grained; clear 



on three sides ; 4th side 

 old, with bad defect 4 

 ins. from one end. 

 Bulged and failed at 

 defect. 



2.22 X 2.22 X 9.07 8177 37.5 Straight grained and 



clear ; one bad season 

 crack. Failed by crip- 

 pling. 



2.13 X 2.20 X 9.15 6850 36.5 Straight grained; 



small knot near one 





corner 3 ins. from end. 

 Failed at this knot. 



58 



