UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1136 
Washington, D.C. T May 12, 1923 
KILN DRYING HANDBOOK 
By 
ROLF THELEN, In Charge, Section of Timber Physics, Forest Products Laboratory, Forest Service 
CONTENTS 
Page 
Purpose 1 
Moisture in wood 1 
Ceneral principles of drying wood 5 
Heatin the lain 6 
Humidity in the lain 14 
Air circulation in the kiln 20 
Drying and drying stresses 23 
Drying schedules » 31 
Kilntypes , . . 45 
Piling lumber for kiln drying . . . 53 
Details of kiln operation 56 
Air seasoning ■ 63 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1923 
