About half an ounce; a cubic foot will therefore weigh about 54 pounds, and 32 cubic inches, one pound. [Sidenote: 88]] 32. How is government powder packed? In barrels of 100 lbs. each; the barrels being large enough to allow sufficient space for the powder to move when rolled to prevent its caking. 33. How are the barrels marked? On one head with the _place_ and _year_ of manufacture, and with the kind of grain, _cannon_, _musket_ or _rifle_; on the other head with the _year_ in which it was _proved_ and the _proof-range_, leaving room for subsequent proofs, which are marked in the same manner. 34. When powder is injured by dampness, can it be restored? If the water absorbed does not exceed 7 per cent., it can be by drying. If it has absorbed from 7 to 12 per cent., after drying, it remains porous and friable, and is unfit for transportation. In this case it is better to work it over. 35. How is powder stored? In magazines especially constructed for the purpose. The barrels are generally placed near the sides, three tiers high, or four tiers if necessary; small skids should be placed on the floor and between the several tiers of barrels, in order to steady them, and chocks should be placed at intervals on the lower skid, to prevent the rolling of the barrels. 36. How are the different kinds of powder arranged? Those barrels of the same kind, place and date of fabrication, and proof range, are piled together. 37. Should it be necessary to pile the barrels more than four tiers high, what is done? The upper tiers are supported by a frame resting on the floor; or the barrels may be placed on their heads, with boards between the tiers. [Sidenote: 89]] 38. What is necessary for the preservation of the powder? The magazine should be opened and aired in clear dry weather, and the ventilators should be kept free. 39. How may the moisture of a magazine be absorbed? By chloride of lime suspended in a box under the arch, and renewed from time to time. 40. When the magazine is open, what precautions should be observed? The sentinel or guard should have no fire-arms, and any one who enters it should take off his shoes, or put socks over them. No sword or cane, or anything which might occasion sparks should be carried in. 41. How should powder in barrels be transported? The barrels should never be rolled; they should be carried in hand-barrows, or slings made of rope or leather. In wagons, the barrels should be packed in straw, and not allowed to rub against each other, and the whole covered with thick canvas. 42. What precaution should be used to prevent powder caking? The barrels should be taken outside the magazine and rolled on boards. 43. Where should cartridge bags be filled? In the filling room of the laboratory, or a small magazine, and not in the general magazine. [Sidenote: 90]] PART IX. PROJECTILES. 1. What projectiles are made use of in the service?