DUSTING LARGE-GRAIN POWDER.
Object of dusting.
The keeping qualities of powder are very much improved by removing the dust, which quickly absorbs moisture from the atmosphere. How performed for large-grain.This operation, for large-grain, is performed by cylindrical reels, about 8ft. 6in. long, and 3ft. 8in. in diameter, clothed with 28-mesh canvas, which revolve at the rate of thirty-eight times per minute. Those for large-grain are called horizontal reels, in contradistinction to those for fine-grain, that are called slope reels. Each is enclosed by a wooden case, to prevent the dust flying about the house. When the powder has run its time, one end of the reel is lowered. It then runs out into barrels placed to receive it. Glazed at same time.This entirely separates the dust, and imparts a fine black gloss, which is sufficient glazing for the large-grained powder.