=To disassemble and to clean the cylinder.=—For cleaning, the cylinder is dismounted and emptied and the cylinder head, counter recoil buffer, and piston rod removed. The interior of the cylinder, the piston, the counter recoil buffer and the stuffing box should then be thoroughly cleaned by the use of cotton waste. The removal of the packing is not necessary in cleaning. The cylinder bore should be carefully inspected, and if any rust has formed it should be removed with coal oil, using if necessary, fine emery cloth. The latter must be used with great care to prevent any increase in the clearance between the piston and the cylinder. If rubbing, burring, or scoring of the parts is noted, the rough spots should be carefully smoothed down by a skilled workman with a dead smooth file or with emery cloth, and the cause of the roughness ascertained and removed. Where unusual rubbing or scoring has occurred, the facts will be reported to the Officer of the Ordnance Department charged with the duty of keeping the battery in repair, for his information and action. The exterior of the cylinder should be kept well oiled and free from rust and dirt, and an inspection made at least once a month to ascertain its condition. Where rust has formed it should be removed with coal oil, and, if necessary, emery cloth. For shipment or storage, or where the carriage is to stand without firing for extended periods, the cylinder should be coated with the light slushing oil used for the bore of guns. =To fill the recoil cylinder.=—If the cylinder is not completely filled, loss of stability will occur and higher stresses than normal will be developed in the carriage. For this reason the cylinder should be filled with the greatest care, a commissioned should, himself, verify that the cylinder is full and that no air is left in it, exception of the void noted below. It is far easier to fill the cylinder when it is disassembled from the cradle. If assembled in the cradle, bring the gun to its maximum elevation and remove both filling and drain plugs. It is necessary that the drain plug holes should be lubricated on top of the cylinder. Fill through the hole in the piston rod. Allow a few minutes for the air to escape and the oil to settle.