“The confession of ignorance is the road to wisdom.”

To Write on Metals

Cover the place you wish to inscribe with melted beeswax.  After this is settled, write the inscription in the wax, but be sure that the writing will be with a sharp instrument that will lay the metal bare where written.  Then fill the written words well with the following:  Eight parts of nitric acid to one part of muriatic acid.  Mix well before using.  Let this acid remain in the letters for about ten minutes, then wash off.

To Petrify

Take an equal quantity of pebbles, powdered chalk, gem salt, rock alum, and white vinegar.  Mix well, and any wood will petrify in it.

Hard Cement

Iron borings and salt water; mix in a little sal ammonia

Soft Cement

White lead in oil and iron borings.

Transparent Blue

For steel or iron of different kinds, and for watch hands, Demar varnish, 1/4 gallon; round Prussian blue, 1/4 ounce.  Mix this well.  This makes a fine blue color.

To Copper the Surface of Iron

The articles to be coppered should be made perfectly clean.  This done, wash in the following solution:  Sulphate of copper, one-half pound; rain water, one and one-half pounds.  The article, whether steel or iron, will then look like copper.

Browning for Gun Barrels

Tincture of steel or tincture of iron (unmedicated), 3/4 oz.; spirits of niter, 3/4 oz.; black brimstone, 1/4 oz.; blue vitriol, 1/2 oz; corrosive sublimate, 1/4 oz.; nitric acid, 1 drachm; copperas, 1/4 oz.; 1 1/2 pints of rain water.  Mix well.  Polish the barrel, then rub with quick-lime.  Apply the browning fluid with a clean white cloth.  Apply one coat and set in a warm dark room for twelve hours.  Then rust will form.  Cord this down with a gunmaker’s cord and rub off with a clean cloth.  If a darker shade is wanted, repeat the application.

Brassing Iron

Clean the iron from all organic matter and plunge into melted brass.

To Make Looking Glass

To make a finer looking glass than the common mercury glass, take 60 grs. Nitrate of silver, 90 inims of spirits of wine, 3 grs. Of ammonia, 90 minims of water.  When nitrate of silver is dissolved, filter the liquid, add 15 grs. Of sugar in 1 1/2 oz. of water and 1 1/2 oz. spirits of wine.  Now cover one side of a glass with beeswax or varnish or gum, to prevent the silver from sticking to one side; then place the glass in the mixture for a day or two.  This will make a splendid looking-glass, although more costly than quicksilver.

To Drill Glass

Glass can be drilled by an ordinary drill, hardened, but not tempered.  The steel must be of a high percent.  Carbon.  In drilling, do not give too much pressure, and run the drill at a high velocity.  Spirits of turpentine, with camphor dissolved in it, should be used, instead of oil, on the drill.

Brazing

Heat the article to a heat too hot to hold it in your hand.  If the article has been polished, heat a little more, and wet it with a linen rag dipped in vinegar; then apply a mixture of German gal mixed with a little spirits of wine varnish.

To Make Grindstone

Take 30 parts of river sand, 2 parts of glass, 10 parts of shellac.  Melt this in an iron pot, and pour into a mold.

Emery

When I was a child, I asked an old smith what emery wheels were made of, and he said, “I believe they are made of steel and iron borings, etc., pressed or melted together.”  Emery was first discovered in the Grecian archipelago.  It is found in amorphous masses and in granules in soils, and is a species of rock, or very hard stone.  The Turkish emery has had a reputation for being the best.  The crude ore is separated, assorted, and graded, then crushed into grains, flours, and the different sizes of grains numbered.  When it comes to a number about 180, it is designated flour emery, and is separated by floating, and marked by letters.

The reason why emery cuts better than ordinary gravel or crushed granite is to be found in the fact that granite or sand, when crushed, will show a fracture of an obtuse angle, while a grain of emery or corundum will always break square or concave fracture, and wear will not dull or smooth it as would stone of any other kind.  This is the reason emery cuts, while sand or grindstone wears.  Emery wheels are made in different ways and by different methods.  Some are cemented and pressed, others cemented with different cement, and then put through a heating process.  The emery wheel is the most useful invention of modern times.  It is found in every shop, and in different sizes.  It is a labor-saving tool, but like so many other useful inventions, coupled with a certain risk to life and limb.  Great care should be taken in selecting the best wheels, as well as an arbor that will run true.  I take pleasure in recommending both the emery and buffing wheels, as well as arbor, manufactured by the Chicago Wheel & Mfg. Co., 39 Randolph St., Chicago.  An illustration of these is shown in Figs. 70 and 72.

Hanging Bob Bunks

In making bob sleds, there are no essential rules to lay down, with the exception of the hanging of the bunks.  It will be noticed in a worn bob shoe that it is worn out at one end.  The front or the hind end is worn the most.  This is so because the bunk is not hung where it belongs.  For the front sled, hang the bunk one inch behind the center of the tread, not the center of the runner.  With a straight edge, find the center of the tread or run of the runner; then place, as before said, the bunk of the front runner one inch behind the center, and the bunk on the hind runner two inches behind the center.  The front sled is generally lifted by the pull in the tongue, and needs less back setting than the hind runner.  In this method, it is found that the sleds will run easy; if, on the other hand, the bunk is hung in front of the center, the runner will run heavy in the bend and root it in the snow.

Resistance and Tensile Strength of Various Metals and Other Materials

Weights of Various Metals