Other Current Literature 239 



A well designed and beautifully illustrated publication con- 

 taining information and material for use in the public schools of 

 Alabama in the observance of Bird Day, May 7, 1915. 



Fourteenth Annual Report of the State Board of Forestry of 

 the State of Indiana, 191^1914. Indianapolis. 1915. Pp. 100. 



Flood Protection in Indiana. By W. K. Hatt. Bulletin 4, 

 Indiana Bureau of Legislative Information. Indianapolis. 1914. 

 Pp. 51. 



On April 20, 1914, the Governor of Indiana appointed a flood 

 commission to consider the extent of damages due to floods in 

 the State and to recommend measures to provide relief in the 

 future. This pamphlet is an abstract of the findings prepared in 

 popular form in advance of the main report. 



Principles of Kiln Drying Lumber. By H. D. Tiemann. Re- 

 print from Lumber World Review. Chicago. January 25 and 

 February 10, 1915. Pp. 6. 



This paper discusses the various factors influencing the drying 

 of lumber and suggests practical methods of control. Although 

 much of the information has already appeared in other publica- 

 tions, a number of interesting details might be mentioned. 



One is in reference to the fibre saturation point. In most 

 woods shrinkage does not occur until the free water in the cell 

 cavities has been removed and loss from the cell walls begins. 

 Certain species, notably Thuja plicata and Sequoia sempervirens, 

 are exceptions to the rule, and collapse of the cell walls may 

 occur in excessively wet spots or bands during the process of 

 evaporation of the free water. Mr. Tiemann's explanation is 

 "that the cell walls, which are practically impervious to air while 

 wet, but through which water may readily pass, become soft and 

 plastic when heated. Under this condition those cells which are 

 completely full of water to start with are subjected to an internal 

 suction or tension produced by the depletion of the water in the 

 cavity by its evaporation through the cell walls. The cells then 

 collapse like rubber tubes, one layer after another." 



Reference is made to an unpublished report by Frederick Dun- 

 lap on "The Heat of Absorption of Water in Wood," in which it 

 is shown that to remove moisture from wood heat in addition to 



