Common Gunpowder. Potassium nitrate, 75 parts; charcoal, 15 parts; sulphur, 10 parts.
Giant Powder. 36 per cent. nitro-glycerine; 48 per cent. nitrate of potash; 8 per cent. of sulphur; 8 per cent. charcoal.
Fulminate. Chlorate of potassia, 6 parts; pure lampblack, 4 parts; sulphur, 1 part. A blow will cause it to explode.
How to Keep Clean. Olive oil is the proper substance to rub over files, as this will prevent the creases from filling up while in use, and preserve the file for a longer time, and also enable it to do better cutting.
To Renew Old Files. Use a potash bath for boiling them in, and afterwards brush them well so as to get the creases clean. Then stretch a cotton cloth between two supports, and after plunging the file into nitric acid, use the stretched cloth to wipe off the acid. The object is to remove the acid from the ridges of the file, so the acid will only eat out or etch the deep portions between the ridges, and not affect the edges or teeth.
For Wood. For the kind where it is desired to apply with a brush, use 100 parts sodium silicate; 50 parts of Spanish white, and 100 parts of glue. It must be applied hot.
Another good preparation is made as follows: Sodium silicate, 350 parts; asbestos, powdered, 350 parts; and boiling water 1,000 parts.
For Coating Steel, etc. Silica, 50 parts; plastic fire clay, 10 parts; ball clay, 3 parts. To be thoroughly mixed.
Oil Stain. Neats' foot oil, 1 part; cottonseed oil, 1 part; petroleum oil, 1 part. This may be colored with anything desired, like burnt sienna, annatto, or other coloring material.
Ballroom Powder. Hard paraffine, 1 pound; powdered boric acid, 7 pounds; oil of lavender, 1 drachm; oil of neroli, 20 minims.
For Perspiring Feet. Balsam Peru, 15 minims; formic acid, 1 drachm; chloral hydrate, 1 drachm; alcohol to make 3 ounces.
For Easing Feet. Tannaform, 1 drachm; talcum, 2 drachms; lycopodium, 30 grains.
Frost Bites. Carbolized water, 4 drachms; nitric acid, 1 drop; oil of geranium, 1 drop.
To cut glass, hold it under water, and use a pair of shears.
To make a hole through glass, place a circle of moist earth on the glass, and form a hole in this the diameter wanted for the hole, and in this hole pour molten lead, and the part touched by the lead will fall out.
To Frost Glass. Cover it with a mixture of 6 ounces of magnesium sulphate, 2 ounces of dextrine, and 20 ounces of water. This produces a fine effect.
To imitate ground glass, use a composition of sandarac, 2 1/2 ounces; mastic, 1/2 ounce; ether, 24 ounces; and benzine, 16 ounces.
How to distinguish them. Wash the metal and put it into a solution of bichromate of potash to which has been added a small amount of sulphuric acid. In a minute or so take out the metal, wash and wipe it. Soft steel and cast iron will have the appearance of an ash-gray tint; tempered steels will be black; and puddled or refined irons will be nearly white and have a metallic reflection.
To Harden Iron or Steel. If wrought iron, put in the charge 20 parts, by weight, of common salt, 2 parts of potassium cyanide, .3 part of potassium bichromate, .15 part of broken glass.
To harden cast iron, there should be added to the charge the following: To 60 parts of water, add 2 1/2 parts of vinegar, 3 parts of common salt, and .25 part of hydrochloric acid.
To soften castings: Heat them to a high temperature and cover them with fine coal dust and allow to cool gradually.
For Aluminum. Dissolve 100 parts of gum lac in 300 parts of ammonia and heat for an hour moderately in a water bath. The aluminum must be well cleaned before applying. Heat the aluminum plate afterwards.
For Brass. Make a compound as follows; Annatto, 1/4 ounce; saffro, 1/4 ounce; turmeric, 1 ounce; seed lac, 3 ounces; and alcohol, 1 pint. Allow the mixture to stand for three days, then strain in the vessel which contains the seed lac, and allow to stand until all is dissolved.
For Copper. Heat fine, thickly liquid amber varnish so it can be readily applied to the copper, and this is allowed to dry. Then heat the coated object until it commences to smoke and turn brown
Heavy machinery oils. Use paraffine, 8 pounds; palm oil, 20 pounds; and oleonaptha, 12 pounds. Dissolve the paraffine in the oleonaptha at a temperature of 160 degrees and then stir in the palm oil a little at a time.
For Cutting Tools. Heat six gallons of water and put in three and a half pounds of soft soap and a half gallon of clean refuse oil. It should be well mixed.
For high-speed bearings. Use flaky graphite and kerosene oil. Apply this as soon as there is any indication of heating in the bearings.
For lathe centers, one part of graphite and four parts of tallow thoroughly mixed and applied will be very serviceable.
For Wooden Gears. Use tallow, 30 parts; palm oil; 20 parts; fish oil, 10 parts; and graphite, 20 parts.
Fire Proof Paper. - Make the following solution: Ammonium sulphate, 8 parts; boracic acid, 3 parts; water, 100 parts. Mix at a temperature of 120 degrees. Paper coated with this will resist heat.
Filter Paper. Dip the paper into nitric acid of 1.433 specific gravity, and subsequently wash and dry it. This makes a fine filtering body.
Carbon Paper. A variety of substances may be used, such as fine soot or ivory black, ultramarine or Paris blue. Mix either with fine grain soap, so it is of a uniform consistency and then apply to the paper with a stiff brush, rubbing it in until it is evenly spread over the surface.
Tracing Paper. Take unsized paper and apply a coat of varnish made of equal parts of Canada balsam and oil of turpentine. To increase the transparency give another coat. The sheets must be well dried before using.