134. Powder for small arms, or musket powder, should all pass through No. 4, none through No. 5, and average from 2,000 to 2,500 kernels in tea grains Troy.
All powder should be well glazed; for small arms more highly than for cannon.
135. The system of granulation adopted by the Army differs from that of the Navy, as follows:
| All Through— | All On— | |
| Mammoth | 0.9 in. | 0.6 in. |
| Cannon | 0.35 | 0.25 |
| Mortar | 0.10 | 0.6 |
| Musket | 0.06 | 0.3 |
It will be seen by this Table that under the Army nomenclature, Navy Rifle nearly corresponds to Army Cannon; that the Army Mortar is the nearest equivalent to Navy Cannon, but with much more fine grain, as it is what passes through the cannon-sieve, but remains on the musket-sieve; and that the Navy Musket has the same size for the larger grain, but contains more small grain than the Army.
In exchanging powder with the Army, it is necessary to attend to these distinctions.
136. Powder-houses or magazines on shore are to be inspected by the Ordnance Officers at least once in every week, and every precaution taken to guard them against danger of explosion, and to preserve the powder dry and in good condition.
137. Powder-barrels in magazines, where there are no racks, should be placed on their sides, with their marked ends towards the alleys, three tiers high, or four tiers, if necessary, with small skids on the floor and between the several tiers of barrels, using chocks at intervals on the lower skids to prevent the barrels from rolling. If it can be avoided, fixed ammunition should not be put in the same magazine with powder in barrels.
138. If it is necessary to pile the barrels more than four tiers high, the upper tiers should be supported by a frame resting on the floor; or the barrels may be placed on their heads, with boards between the tiers.
There should be an unencumbered space of 6 or 8 feet square at the doors of the magazine.