ARTILLERY-MAGAZINE. In a siege, the magazine is made about 25 or 30 yards behind the battery, towards the parallels, and at least three feet underground, to hold the power, loaded shells, port fires, &c. Its sides and roof must be well secured with boards to prevent the earth from falling in: a door is made to it, and a double trench or passage is sunk from the magazine to the battery, one to go in and the other to come out at, to prevent confusion. Sometimes traverses are made in the passages to prevent ricochet shot from plunging into them.