90 



SELLING LUMBER 



Creosoted 

 Lumber Less 

 Liable to 

 Shrink 



Comparative 

 Strength 

 of Fir and 

 Yellow Pine 



The Chairman : Are there any questions you wish to ask 

 the doctor before he leaves the platform? 



Mr. Christy: Is creosoted lumber for silos less liable to 

 shrink or warp? 



Dr. von Schrenk : Yes, it is, on account of the fact that 

 every pound of creosote that is injected into the timber increases 

 its water-proofing power. A small amount would increase it only 

 to a certain extent. A larger amount, like fifteen or eighteen 

 pounds of creosote, would water-proof it very much more, and 

 that of course would reduce its tendency to warp or shrink, to 

 that extent. 



The Chairman: May I ask a question, Doctor? Does the 

 treatment of yellow pine or any other wood for silo purposes 

 injure the ensilage? 



Dr. von Schrenk : No, it does not. I think I answered that 

 fully. 



Mr. Hervey : What is the comparative strength of fir and 

 long leaf yellow pine? 



Dr. von Schrenk : In general it might be said that grade 

 for grade it is six of one, and half a dozen to the other. There 

 has been a good deal of discussion, through misinterpretation of 

 strength figures for yellow pine and Douglas fir. Some yellow 

 pine man will start out and say that yellow pine is stronger than 

 fir; and the fir man comes back and says, "You are another. 

 Fir is stronger than yellow pine." Now, the safe course to be 

 taken perhaps I can explain that in a very few words all 

 timber varies in strength according to a well known mathematical 

 formula. For instance, long leaf yellow pine might have a 

 modulus of rupture, one of the strength factors, running from 

 seven to fourteen thousand pounds. If you test a sufficiently 

 large number of pieces of pine you will find the strength all the 

 way in between, but you will find a great majority of them will 

 be somewhere in the middle ten or eleven thousand pounds 

 taking those not as absolute figures, but simply as an illustration. 

 It will do the same thing with Douglas fir, and you will find 

 almost the same kind of curve, or the same kind of distribution 

 of strength. Consequently it is easy enough for anybody to pick 

 up a piece of yellow pine and say it is very much stronger than a 

 piece of Douglas fir, arid vice versa. But if you have the two 

 together, practically graded under the new density rule, you will 



