LUMBER 403 



difficult woods, should be constructed and equipped in a 

 way to insure such regulation. 



A dry kiln may consist simply of a box in which lumber 

 can be heated, or of a good-sized building or group of build- 



FIG. 192. A Dry Kiln. 



ings (battery) containing steam pipes, condensers, sprays, 

 and various air passages capable of adjustment to regulate 

 the amount of ventilation. The elaborateness of the kiln 

 depends, of course, mainly upon the value of the lumber that 

 is to be dried. Kiln-dried lumber is valuable if it is to be 



