File:Bulletin (1910) (14592157349).jpg

Identifier: bulletinu20unit (find matches)
Title: Bulletin
Year: 1910 (1910s)
Authors: United States. Bureau of Mines
Subjects: Mines and mineral resources Mines and mineral resources Mining engineering
Publisher: Washington U.S. Govt. Print. Off. (etc.)
Contributing Library: Gerstein - University of Toronto
Digitizing Sponsor: University of Toronto

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ion. pointed toward a pile of coal dust. Figure 1 is a sectional outlineof part of the gallery, showing the location of the horse. DISCUSSION OF RESULTS. In the first tests a charge of 1^ pounds of black powder was used,tamped with 2J pouncte of clay. With this charge dusts larger than60-mesh did not even ignite (except for slight prolongation of powderflame in tests 1 and 2), but 80 to 100 mesh dusts and also 60 to 80mesh dusts in three out of four tests did ignite and propagate theexplosion. It may be assumed that finer sizes would propagate, sono tests were made of them. A series was then tried with double the quantity of black powder,or 2\ pounds, and with 2 pounds of clay stemming, which was all thatthe depth of the bore hole would allow. The effect was notable; 60 to80 mesh dust propagated the explosion and so did 40 to 60 mesh dust.With 20 to 40 mesh dust, while there was ignition, there was onlypartial propagation, but the indications were that with a still larger Iliilil >
Text Appearing After Image:
COKE PRODUCED FROM 80 TO 100 MESH DUST.Photographed on half-inch squares. Experiment G-2894.

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