in Ohio, Burned For More Than Twelve Months 



..1& 



only to add to the intensity of the heat. It was estimated that a million gallons of water were 

 poured on the fire without subduing it. The smut-dust theory is advanced as the cause of it 



grain were destroyed. The grain loss due 

 to the fires investigated reached about 

 $50,000. 



The experimental work carried on during 

 the investigations proved conclusively that, 

 under favorable atmospheric conditions, 

 static electricity is present on ail types of 

 machines. It appears that the largest 

 discharges of static electricity were ob- 

 tained from the steel machines. 



The fires and explosions occurred, as a 

 rule, when fall wheat was being threshed, 

 and very rarely occurred dur- 

 ing the threshing of spring 

 wheat. The discharge from 

 the machines, while smutty 

 wheat was being threshed, 

 was more noticeable than 

 when clean wheat was 

 going through the process. 

 l-"all wheat, as a rule, con- 

 tained much more smut than 

 spring wheat. The thcor\- 

 was advanced that the small 

 particles of smut easily be- 

 came electrified when the 

 kernels were broken up by 

 the cylinder teeth and that 

 each particle became charged 

 with static electricity. 



From a study of conditions, several 

 methods have been developed for prevent- 

 ing explosions and fires. The investigators 

 believe that a system of electrical con- 

 nection between all of the moving parts and 

 a common wire, and a thorough grounding 

 of this common wire, will prevent a large 

 percentage of the fires that are due to the 

 presence of static electricity and an explo- 

 sive mixture of smut-dust and air. Several 

 methods of wiring are recommended, the 

 system varying with the type of machine. 



»^i 



Pulhng a threshing machine away from a straw-stack after 

 an explosion and fire, to avoid a greater conflagration 



835 



