82 NATURAL HISTORY OF THE FARM 
standing, needing cutting. Fire was the cutting agent first 
employed. ‘Trees were burned down by building fires about 
their bases, and then by similar process they were cut in 
sections. It was only for long-keeping fires that such fuel 
was needed: there was always excess of kindling-stuffs 
available for making quick fires.. 
All wood will burn and give forth heat, but one who knows 
woods will not use all kinds: it is only the degenerate 
Fic. 43. Western yellow pine dismantled and ignited by lightning (U. S. 
Bureau of Forestry). 
modern, who will do that—who will go to the telephone and 
order a cord of wood without further specifications. Heavy, 
close-grained, hard woods as a rule burn more slowly and 
yield more heat than the lighter, more open-textured soft 
woods. Combustible resins vary the rate of burning, and the 
amount of heat produced: but the greatest differences in 
burning qualities are due to the amount of water present. A 
punky old log that when dry will burn like tinder, will soak up 
water like a sponge and, becoming ‘‘water-logged,” will not 
