J98 



THE TIMBERS OE THE WORLD 



be advantageous, as the thermal kihi would need some means such as 

 steam jets or exhaust fans to assist in the circulation ; but as a rule, for 



Green Umhe^ 



B F.STURTEIVANT FAN OPEPATED. 



Diagram of I'^ak-operatiid Pkogkessive Kiln. 



jjrogressive dryers the thermal circulation shows to most ad\'antage as 

 regards ease of working, while it produces excellent results. 



UK? At 



STLIRTIiVANI l'ROr,KESS]\-E l\ILN. 



lii'KCh treex were frllefi and sawn, the tinihcr drieil aiLd tlieii plmed in less than three weeks. 



If a compartment kiln is \-ery long and has doors at both ends, it 

 can be operated in a semi-progressive manner. This is done l)y pihng 



