=To clean, lubricate and care for the wheels.=—The wheel and wheel fastenings should be dismounted periodically and the fastenings, hub boxes, axle arms, and axle bore cleaned and examined. All roughness due to scoring or cutting should be smoothed off. The hollow part of the axle acts as a reservoir for the oil to lubricate the wheel bearings. Experience will show how much oil is needed, but enough should be used to insure that the oil will pass through the axle arms to the hub caps. The nuts on the hub bolts should be tightened monthly during the first year of service and twice a year thereafter. The ends of the bolts should be lightly riveted over to prevent the nut from unscrewing. When the hub bolts are tightened, the hub band should be screwed up as tightly as possible against the lock washer at the outer end of the hub ring. GENERAL INSTRUCTIONS FOR THE CARE AND MAINTENANCE OF MATERIEL Assembling and Disassembling. (a) Cradle mechanism, cylinder, springs et cetera. All work upon recoil cylinders, sights, and other optical equipment should be done in the presence of a commissioned officer. The recoil cylinder should never be clamped in a vise, but when necessary to hold it from turning, a spanner applied to the front end of cylinder should be used. Never remove the cylinder end stud nut when the piece is at an elevation. See that proper kind of oil is used in cylinders and for lubrication. Strain the oil used in filling the cylinders through a fine clean cloth and be sure that the receptacles used in handling the oil are clean. Take every precaution to keep the interior of the cylinders clean and to prevent the entrance of foreign particles. In assembling the gland be sure that at least four threads of the gland are engaged with the threads of the cylinder head. Lash parts with copper wire to prevent unscrewing. Close down the ends of the recoil-indicator guide to avoid loss of the indicator. Prevent possible injury to cannoneers by causing them to stand clear of the counter-recoil spring column in assembling or dismounting. Remove cylinder end stud screw before trying to unscrew cylinder end stud. (b) Gun In moving the gun on or off the cradle, provide ample support for the breech end, so that the gun clips are in prolongation of the cradle guides; if this is not done the cradle guides may be ruined. (c) Elevating and traversing mechanism. If the gun will not remain at the elevation at which set, the crank shafts are probably not correctly assembled. If the elevating screw do not house in traveling, they are incorrectly assembled. (d) Sights and quadrant. Frequently verify the adjustments of sights and quadrant. Require special care in handling sights. Do not permit cannoneers to use front sight as a handle in mounting. Be sure that the range disk of the quadrant and range strip of the rear sight shank are graduated for the particular type of ammunition used by the battery. This also applies to the fuze setter.