When, through carelessness or unpreventable causes, plummer blocks and other detachable portions of machinery become clogged with sticky deposits of grease and impurities, a simple mode of cleansing the same is to take about 1000 parts by weight of boiling water, to which add about 10 or 15 parts of ordinary washing soda. Keep the water on the boil and place therein the portions of the machine that are to be cleaned; this treatment has the effect of quickly loosening all grease, oil, and dirt, after which the metal is thoroughly washed and dried. The action of the lye is to form with the grease a soap soluble in water. To prevent lubricating oil hardening upon the parts of the machinery when in use, add a third part of kerosene. PREVENTING SCALING AND PRIMING IN BOILERS. Graphite “black-lead” added to the water in a boiler prevents scaling and priming. My method is to paint the inside of the boiler with a good coat of graphite mixed with water to the consistency of thin gruel, and let it stand till dry. It will not be amiss to give a second coat before getting up steam. Even if slight scaling has already taken place, the graphite particles will penetrate and the scale come away gradually. CLEARING SCALE-STOPPED PIPES. Where the water contains a large amount of mineral in solution, the pipes, particularly the small ones, inch to two inch, quickly become useless because of the rapid deposition of scale. I have seen in West Australia tons of small pipes thrown on to the scrap heap after a few months use, because of this difficulty. The treatment now indicated, which is my own invention, will make such pipes as good as new at small expense. Have a brick trough a little longer than your pipe. In this put a fire of wood, charcoal, coke, or a mixture of such fuel. Lay the pipes, a few at a time, in this. Heat slowly to cherry red. Then with pinchers suddenly immerse in a second trough of cold water, supporting one end above the water level. Most of the scale or incrustation will be violently ejected. With a long pipe, if the heat has not been regular, some may still adhere. Then usually tapping with a hammer will detach it. If not, a second heating and immersion will do so, leaving the interior as clean as when made. It is hardly necessary to add that ’tis best to stand clear of the ends when the explosion takes place. AN EXCELLENT ANTI-FRICTION COMPOUND. 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; graphite “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 ½ oz., sweet oil 1 oz. Rub on with a piece of rag. A SOLVENT FOR RUST.