DUST EXPLOSIONS IN GRAIN SEPARATORS. 3 
various phases of the problem were considered with the State College 
staff. : 
CONDUCT OF INVESTIGATIONS. 
Although investigations by the Department of Agriculture were 
not conducted in the field during the 1914 threshing season, samples 
of wheat smut dust from the Pacific Northwest were obtained at the 
close of the season. Experiments at that time indicated that the 
material was highly inflammable and might be associated with the 
frequent fires and explosions in grain separators. 
The entire season extending from the first week in July to the 
middle of September, 1915, was spent in field work in the territory. 
Effort was made to visit the scene of each explosion or fire as soon 
as possible after it had taken place and obtain all the available in- 
formation pertaining to the occurrence. Arrangements previotsly 
had been made so that prompt reports could be received at the Spo- 
kane office, through various channels, and also by the men in the 
field, so that no time would be lost in reaching the scene of the 
explosion. In nearly 150 cases the investigator was on the ground 
either immediately or within a few hours after the occurrence. In 
many instances the explosions were so sudden and violent that the 
crew could give very little information, but it was possible in the 
majority of cases to make valuable deductions. A large percentage 
of the thresher owners would not advance an opinion, but many of 
them believed that matches or explosives had been placed in the 
bundles. In many cases, however, this was mere conjecture and not 
supported by evidence. 
CLASSIFICATION OF EXPLOSIONS. 
TERRITORY AFFECTED. 
The largest number of the 166 explosions reported occurred in the 
counties of Whitman and Spokane in eastern Washington, and the 
counties of Latah, Lewis, Kootenai, and Nez Perce, in northern 
Idaho. Eighty-three per cent of the total number of explosions and 
fires reported occurred in this district. Of these 70 per cent occurred 
in Washington and 13 per cent in Idaho. About 11 per cent of the 
total number reported occurred in the Big Bend section in the Co- . 
lumbia River Valley in Washington, comprising the counties of | 
Adams, Lincoln, Grant, and Douglas. The remaining explosions 
occurred in Walla Walla, Garfield, Yakima, and Klickitat Counties. 
The field investigations, however, generally were confined to the 
Palouse country in eastern Washington and the northern Idaho ter- 
ritory. 
FREQUENCY OF EXPLOSIONS. 
The explosions began with the opening of the season in the Big 
Bend country about the middle of July and continued until the 
