---------------------+-----------+------------+------------------------ Object Attacked. |Gunpowder. | Guncotton. | Remarks. ---------------------+-----------+------------+------------------------ Brick arch. |} {| ¾_BT²_ }|The length of breach, Brick wall 2 ft. or |} {|2 lbs. per}}|_B_, should not be less less. |}3/2_BT²_ {| foot run }|than the height of the Brick wall over 2 ft.|} {|½_BT²_ }|wall to be brought Brick piers. |} {|⅔_BT²_ }|down. | | | Hard wood in any | 40 to 100 | 3_BT²_ |In a concentrated form, stockade, | lbs. for | |charge, or for trees palisade, single | stockade | |not over 12 in. in timbers, trees, etc. | | |diameter in a necklace. | | | Do., do. | | ⅜_T²_ |In auger-hole; when | | |the timber is not | | |perfectly round, _T_ | | |smaller axis. | | | Soft wood. { | Half the charges | { | for hard wood | | | | Breastwork of | 60 to 80 |4 lbs. per | horizontal balks, | lbs. per | foot | or earth between | 5 feet | | sleepers up to | | | 3½ ft. thick. | | | | | | Heavy rail stockade. | | 7lbs. | | | per ft. | | | | Fortress gate. | 200 lbs. | 50 lbs. | | | | Iron plate. | |3/2_Bt²_ | | | | Field- or siege-guns.| | 1½ lbs. |On chase near muzzle. | | | Heavier guns. | | 4 lbs. |In bottom of bore, | | |tamped with water or | | |sand. | | | First-class iron rail| | 2/8 lb. |Touching web of rail | | |and near a chair. | | | " steel " | | 4 oz. |Four rails placed around | | |the charge will be cut | | |simultaneously by it. ---------------------+-----------+------------+------------------------