Current Literature. 705 



up this interesting question and test its suitability to some of our 

 conditions. 



R. Z. 



The Specific Heat of Wood. By Frederick Dunlap. Bulletin 

 no, U. S. Forest Service. Washington, D. C. 1912. Pp. 28. 



The specific heat of wood is its heat capacity compared with 

 that of an equal volume of water. This bulletin deals with the 

 specific heat of so-called "ovendry" wood, determined by measur- 

 ing in a slightly modified form of Bunsen's ice calorimeter the 

 quantity of heat given off by small cylinders of wood in falling 

 from a temperature slightly above that of boiling water to that of 

 melting ice. The standard "oven dry" condition was produced by 

 drying the green or air dry wood for two days at above 105° C. 

 and then weighing the cylinders at intervals until their weight 

 became constant to within i milligram for eight hours. Material 

 for the experiments was received from 16 important indigenous 

 economic species which varied greatly in density and structure. 

 This included material from different parts of the same plant and, 

 in the case of species, from trees grown under varying factors of 

 locality. 



The conclusions to be drawn from these experiments are: 



1. The average specific heat of "oven dry" wood is approxi- 

 mately 0.3249. 



2. The specific heat of "oven dry" wood varies but slightly with 

 change of species. Lowest recorded mean specific heat Chest- 

 nut .317, highest .337 Longleaf Pine. 



3. The variation in specific heat within a species due to vari- 

 ation in locality is so small and inconsistent as to furnish no re- 

 liable basis for concluding that locality influences the specific heat 

 of wood. 



4. The transformation of sapwood into heartwood does not 

 appreciably affect its specific heat. 



In addition to the numerous experiments upon the specific heat 

 of "oven dry" wood obtained by cooling cylinders from 106° — 0° 

 C, preliminary experiments with cooling from temperature of 

 6o°-\- and 23° C indicate a great variation of specific heat with 



