For use on cams and stamper shanks, which will be harmless should it drop into the mortar or stamper boxes, is graphite (black-lead) and soft soap. When the guides are wooden, the soft soap need not be added; black-lead made into a paste with water will act admirably. TO CLEAN BRASS Oxalic acid 1 oz., rotten stone 6 oz., powdered gum arabic 1/2 oz., sweet oil 1 oz. Rub on with a piece of rag. A SOLVENT FOR RUST It is often very difficult, and sometimes impossible, to remove rust from articles made of iron. Those which are very thickly coated are most easily cleaned by being immersed in a nearly saturated solution of chloride of tin. The length of time they remain in this bath is determined by the thickness of the coating of rust. Generally from twelve to twenty-four hours is long enough. TO PROTECT IRON AND STEEL FROM RUST The following method is but little known, although it deserves preference over many others. Add 7 oz. of quicklime to 1 3/4 pints of cold water. Let the mixture stand until the supernatant fluid is entirely clear. Then pour this off, and mix with it enough olive oil to form a thick cream, or rather to the consistency of melted and re-congealed butter. Grease the articles of iron or steel with this compound, and then wrap them up in paper, or if this cannot be done, apply the mixture somewhat more thickly. TO KEEP MACHINERY FROM RUSTING Take 1 oz. of camphor, dissolve it in 1 lb. of melted lard; mix with it (after removing the scum) as much fine black-lead as will give it an iron colour; clean the machinery, and smear it with this mixture. After twenty-four hours rub off and clean with soft, linen cloth. This mixture will keep machinery clean for months under ordinary circumstances. FIRE-LUTE An excellent fire-lute is made of eight parts sharp sand, two parts good clay, and one part horse-dung; mix and temper like mortar. ROPE-SPLICING A short splice is made by unlaying the ends of two pieces of rope to a sufficient length, then interlaying them, draw them close and push the strands of one under the strands of the other several times. This splice makes a thick lump on the rope and is only used for slings, block-straps, cables, etc.