16 



THE SPECIFIC HEAT OF WOOD. 



wood. The values obtained by the experiments along this line are 

 given in Table 2: 



TABLE 2. Results of determinations on the same species of wood grown in different 



localities. 



HEARTWOOD AND SAPWOOD. 



The differences met in cylinders taken from the heartwood and sap- 

 wood on a line passing from the pith of a tree to the bark are even 

 smaller than the differences in a species grown in different localities. 

 The results are given in Table 3 : 



TABLE 3. Results of determinations on heartwood and sapwood of Douglas fir. 



CORRECTED RESULTS. 



The above results were generalized by means of a frequency curve. 

 (Appendix, p. 21.) This curve revealed the fact that the results 

 are subject to a systematic error which tends to make the average 

 result of 0.325 too low by about five-tenths of 1 per cent. This error, 

 there is no reason to doubt, has its origin in the loss of heat during 

 the transfer of the specimen from the oven to the calorimeter. Apply- 

 ing this correction gives a corrected value of 0.327, which is the most 

 acceptable result for the mean specific heat of oven-dry wood through 

 the interval between 106 C. and C., and is believed to be correct 

 within six-tenths of 1 per cent. 



