=To Attach Leather to Metal.=--Coat the metal with a hot solution of glue and the leather with a hot solution of nut-galls. DIRECTIONS FOR CLEANING MOULDY LEATHER. First. Wash thoroughly in soap-suds with a brush, so as to remove all dirt and mould. Second. Sponge with clean water, and before the leather dries apply with a sponge tied to a handle a solution of ammonia and water in equal parts, using 4 Fs. ammonia. Third. Apply, when dry, a coat of leather blacking. (A good blacking can be made by placing in 5 gallons of best cider vinegar ¼ pound of pulverized nut-galls, 2 pounds of copperas, 1 pound of iron filings or chips, and letting it stand for five days before use, stirring carefully from time to time.) Fourth. After the leather is dry apply a good coating of oil--1 part of kerosene and 4 parts of neat's-foot. Apply freely so as to soften the leather, and let it dry sufficiently. Fifth. Brush the pieces well, and put on with a sponge a thin coat of gum tragacanth, dissolving ¼ pound of gum in 1 gallon of warm water. After drying the leather should be repacked, if desired to store it. Harness in use which becomes hard from perspiration or from being wet should be washed, oiled, and rubbed as above, without applying the solution of ammonia, or of blacking unless the leather has become reddish. CARE OF HARNESS. The estimated life of a set of artillery harness is seven years. Harness, after being used, must be carefully wiped and cleaned; if possible, this is done before taking it off the horse; otherwise it is put in good order at the earliest practicable moment, and covered with the sack. Straps and leather parts generally are kept soft and supple; trace-chains and iron parts free from rust. Collars and saddles will be aired and kept perfectly clean. The greatest care must be exercised in keeping the collar where it bears against the horse in perfect order. Harness should be oiled two or three times a year if necessary. The best oil for this use is neat's-foot oil, the unctuous property of which is particularly suitable for preserving the suppleness of the leather; this oil contains no siccative part, and may be used unpurified. Four pints and a half will oil the harness of a team of three pairs. To keep it from becoming rancid, use 1 part kerosene to 4 parts neat's-foot. Before using the oil every part of the leather must be perfectly cleaned and washed, without letting the water soak deeply into the leather; while still damp blacken with dye those places which have become red; when the leather begins to dry, oil it, spreading the oil on with a sponge or thick, soft brush. When neat's-foot oil cannot be had, pure fish-oil may be used, but it must be carefully ascertained that it does not contain any siccative matter, which would make it injurious.