Gun′pow-der-mill.
Fig. 2346 shows an arrangement by which several gunpowder rolling-mills are driven from a water-wheel a by bevel and spurgears b b e e. The cast-iron or stone rolling-cylinders [1042] c c revolve on a horizontal axis which is carried around by a vertical shaft within the circular trough d, into which a charge, usually 75 or 150 pounds, of the incorporated materials from the rolling barrel has been placed. The rollers are set in motion, slowly at first, and afterwards more rapidly, and kept going three hours for a charge of 150 pounds, or for a less quantity a proportionately less time, a little water being added to prevent danger of explosion should the materials become too dry. A scraper follows each roller to keep the composition exposed to the action of the rollers. At the end of this time the mass has become thoroughly incorporated, is of a brownish red color, and is termed mill-cake. See gunpowder. |
| Gunpowder-press. |
