Figure 1. — A horizontal pyrolysis 

 zone moving downward at a rate, 

 C, through a weighed fuel basket 

 of depth, 6. A doughnut- shaped 

 basket surrounds the weighed 

 basket to eliminate edge effects. 



PYROLYSIS ZONE 



Figure 2. — A oross-seotional view of a fire spreading horizontally through a fine fuel 

 (complete burnout). A weighed fuel slice is illustrated by Ax. The lower boundary 

 of the pyrolysis zone is the ignition interface with the fuel. 



2 



