KINDLING TEMPERATURE 



73 



the substances will in time be raised to their kindling tem- 

 perature and will take fire. This is called spontaneous com- 

 bustion. 



Linseed oil used by painters is a substance which readily 

 oxidizes. Accumulations of rags saturated with such oil 

 will gather heat of oxidation (if in a place where there is 

 no great movement of air) until the kindling temperature 

 is reached, and a fire is started. Sometimes the dust in 

 the center of a great pile of coal produces heat enough by 

 its oxidation to 

 start a fire in the 

 coal. Some- 

 times the heat 

 produced by the 

 " souring " of 

 hay is sufficient 

 to set the hay 

 on fire. 



A means by 

 which substances 

 can be readily 

 brought to their kindling temperature is very essential if 

 fires are to be easily built. Our forefathers used to strike 

 a flint and steel together so as to make a spark fall upon 

 some fine, dry material (tinder). With this they patiently 

 started the larger fires they needed. 



In frontier days, smoldering tinder was kept in a tinder 

 box," and this served the pioneers instead of matches. 

 Until less than a hundred years ago the use of flint and steel 

 was the prevailing method of obtaining fire. 



This method of starting fire was difficult and uncertain. 

 The invention of the friction match has changed all this and 



TINDER Box AND FLINT AND STEEL 



