OP ARTS AND SCIENCES. 



313 



TABLE X. 



Deflection of Piece No. 8, Series No. 3, itn-der a Load of 301 lbs. ok 

 ^ OF ITS Calculated Breaking Weight. 



The only reason which the writer can give for the low value of R 

 in the third series is that the plank was sawn from the outside of the 

 tree. It will be noticed that the values of It ran very high for the 

 pieces in Series No. 2, also that the average value of R for Series 

 No. 1 is only about 8 per cent less than that for Series No. 2, while 

 it is about 23 per cent greater than the average for Series No. 3. 



This would lead one to infer that ordinarily dry lumber does not 

 have its strength materially increased by being kiln dried. 



Comparing Tables I. and II., we see that the average value of the 

 modulus of elasticity for the beams of unseasoned spruce is fully as 

 large as that for the kiln-dried spruce. The beams in Table I., though 

 denoted as unseasoned, were fully as dry as timber which has been in 

 an ordinary building three months, but it was not artificially dried. 



