2 BULLETIN 379^ U. S, DEPARTMENT OF AGEICULTUKE. 



The results of the investigation indicate that the wheat crop 

 contained a large percentage of smut and that the explosions and 

 fires in many cases were due to the formation of an explosive mix- 

 ture of smut dust and air and the ignition of this mixture by static 

 electricity during the threshing operations. This report briefly 

 summarizes the results of the field work relative to the causes of 

 ignition and describes the various preventive devices developed as a 

 result of the investigation. 



PLAN OF INVESTIGATION. 



ORGANIZATION. 



The field work was conducted under a cooperative arrangement 

 between the Bureau of Chemistry, where the general study of grain- 

 dust explosions is being carried on, and the Office of Public Roads 

 and Rural Engineering. Investigators were assigned to the various 

 parts of the territory affected and a central ofiice was opened in the 

 Federal building at Spokane, Wash. J. E. Young, assistant agri- 

 cultural engineer, conducted field investigations in the vicinity of 

 Walla Walla and Rosalia, AYash., and J. C. Y^oodson, assistant agri- 

 cultural engineer, in the territory adjacent to Moscow, Idaho. H. H. 

 Brown, assistant chemist, was assigned to investigations in the 

 vicinity of Colfax, Wash. The organization and direction of the 

 field work and the conduct of the investigation were in charge of 

 David J. Price, engineer, of the Bureau of Chemistry, and E. B. Mc- 

 Cormick, mechanical engineer, of the Ofiice of Public Roads and 

 Rural Engineering. 



COOPERATION WITH THE UNIVERSITY OF IDAHO. 



The investigations in northern Idaho were conducted in coopera- 

 tion with the University of Idaho at Moscow, represented by Prof. 

 N. S. Robb, of the Department of Farm Crops. Ofiice room, labora- 

 tories, and electrical apparatus were placed at the disposal of the 

 investigators and experimental work was conducted in conjunction 

 with Prof. Angell, of the Department of Physics. The staff was 

 much interested in the explosion problem in its territory and ren- 

 dered vfijuable assistance during the conduct of the investigations. 



CONFERENCES WITH THE STATE COLLEGE OF WASHINGTON. 



Conferences were held at the beginning of the investigations with 

 Dr. Ira D. Cardiff, director of the experiment station. State College 

 of Y^ashington, Pullman, Wash., and members of the staff. This 

 problem had been studied by the station staff in 1914 and the results 

 published in bulletin form.^ During the conduct of the field work 



1 Washington Station Bulletin No. 117, Nov. 3, 1914. Report on Fires Occurring in 

 Threshing Separators in Eastern Washington during the Summer of 1914. 



