Figure 3 . - - Firing the 

 Neal Canyon site, 

 August 1, 1963. 



Firelines were burned out first, after which the major fire was started with a flame 

 thrower on a pickup truck passing once across the middle of the site and again across the lower 

 edge (fig. 3). With minor variations, the fire swept into the tree crowns almost immediately; 

 and at progressive intervals the entire area was covered by running flame. 



The intensity of the fire was measured by integrating devices described by Beaufait. 8 

 These consist of 1 -gallon cans painted flat black and containing 3 liters of water at ambient 

 temperature. The weight of water released as steam through a 1-cm. hole in the can lid is a 

 measure of heat absorbed. 



Eighteen pairs of these water-can analogs were placed on mineral soil (fig. 4) in six 

 evenly spaced vertical lines within the 20-acre study area. Rolling rocks and logs destroyed 14 

 cans, but only four of the 18 pairs were lost. Water loss from the remaining 22 cans ranged 

 from 340 to 1,765 grams, with a mean loss of 939.8 grams (table 2). According to Beaufait's 

 unpublished data, this water loss is comparable to losses during a hot broadcast fire in deep, 

 dry slash. 



8 Beaufait, William R. An 

 integrating device for evaluating 

 prescribed fires. Forest Sci. 

 12(1): 27-29. 1966. 



Figure 4. --Water-can heat 

 integrating device. 



