Prepare oil paint by mixing boiled linseed oil and white lead to a proper consistency, and add some ultramarine or any other color to give it the desired coloring. Add some siccative.

A better method is to take 5 lbs. of raw linseed oil and boil it with half a pound of manganese oxide or a little borate of manganese. Let cool and decant from the sediment, then mix with lead and coloring as directed before. The manganese acts as a siccative.

Von Liebig's Directions are: - Mix 10 lbs. of linseed oil with 150 grammes (5 ounces) of litharge, add 300 grammes of solution of subace-tate of lead, shake well and let subside. Then add white lead and coloring to suit consistency and color. This paint dries quickly.

The parts made of brass, or an apparatus, made of copper, can be kept bright by using slaked lime and woolen rags dipped in melted paraffin.

The Government method prescribed for cleaning brass, and in use at all the United States arsenals, is claimed to be the best in the world. The plan is to make a mixture of one part common nitric acid and one-half part sulphuric acid in a stone jar, having also ready a pail of fresh water and a box of sawdust. The articles to be treated are dipped into the acid, then removed into the water, and finally rubbed with sawdust. This immediately changes them to a brilliant color. If the brass has become greasy, it is first dipped in or rubbed with a strong solution of potash and soda in warm water; this cuts the grease, so that the acid has free power to act. Another method of cleansing brass is to dip in or rub with ammonia the article to be cleansed.

An excellent means employed to protect bright parts of machinery from rust, consists in coating the parts with a mixture of white or yellow wax and turpentine, of a moderately thick consistency. The coating produced after a time is neither perceptible to the nose nor the touch; it, however, penetrates to such an extent into the pores of the metal as to protect it a long time against rust.

Another approved method for the protection of metals as well as stone walls and different other purposes in an industrial establishment is the following: Mix one part of creosote with 5 parts of turpentine, boil until the mixture is clear. Then add 25 parts of paraffine, heat near the boiling point, when the mixture will be ready for use and must be used in this state, as it becomes solid at 140 F. The hot solution penetrates into the pores and forms on the surface a fine enamel coating, which protects against the injurious influences of acids, gases, salts, etc.

A cleansing pomade for all sorts of bright metals may be made of benzine and carbonate of magnesia, mixed to a paste. This has to be kept in wide-mouth bottles, air-tight, otherwise the benzine evaporates; better prepare the paste for immediate use.

Another excellent cleansing pomade for bright metals is made by mixing crocus or jeweler's rouge (finest oxide of iron) with nitro-benzol (artificial oil of bitter almond) to the consistency of a paste. Keep as directed before. Both pomades are used with a woolen cloth and rubbed over the surface to be polished.

Cleansing oil, a product of the fractional distillation of crude petroleum (spec. grav. 0.73 to 0.75), is employed for cleansing all kinds of machine parts. It is applied by means of a rag, saturated with it.