Stencils
A stencil is a piece of heavy paper or thin sheet of metal in which letters or a design are cut through with broken lines, and it is used for marking the letters or design on any smooth surface by daubing a color on it through the open spaces with a brush or sponge.
There are two kinds of stencils, namely (1) those used for practical work and (2) those used for decorative purposes.
How to Cut Stencils.
—You can cut your stencils in either (a) oil board,[86] or (b) in thin sheet brass or copper. Paper stencils, as those cut in oil board are called, are much easier to make than those cut in sheet metal and as they are quite durable they will probably serve your every need.
[86] Oil board can be bought of C. B. Hewitt and Bros., 48 Beekman St., New York.
Cutting Paper Stencils.
—All you need to cut paper stencils with is a sheet of oil board and a pen-knife with a good, sharp-pointed blade. A stencil alphabet is shown at [A in Fig. 82] and by taking a look at it you will see exactly where the lines must be broken to hold the letters together.
First mark out with a pencil the size of the sheet you want the stencil to be and then draw a line down through the middle to divide it into equal parts. For every line of letters you want draw a pair of lines across the oil board and have the space between them whatever you want the height of the letters to be.
When you mark in the name or word start with the middle letter and draw it on the middle line of the board and then draw in the rest of the letters to the right and to the left; by lettering the oil board or metal this way you will get the whole name or word exactly in the middle of the sheet.
Fig. 82. stencil letters and stencils
A. How stencil letters are cut.
B. A stencil for marking boxes.
C. Decorative stencil for wall borders.
To cut the stencil lay it on a smooth board and hold your knife just as you do a pen when you write but with your fingers a little closer to the point. Start at the top of each line if it is a vertical one, or on the left hand side if it is horizontal; hold the knife at a slight angle so that all the lines you cut will slant in toward the center of the letter and so bevel the paper. In cutting the stencil you can turn the sheet around to bring the lines into the best position for cutting.
It does not take much pressure to cut through the board but press down hard enough on the blade to make the first cut go clear through and never cut over the same line twice and also make the cuts run right up sharp into the corners. It takes very small skill to cut stencils but the chief part of the art lies in drawing the letters or the designs on the paper or metal.
Cutting Brass Stencils.
—To cut sheet metal stencils use annealed[87] sheet metal about No. 25 Brown and Sharpe gauge;[88] mark out the letters or design as for paper stencils and then cut them with stencil chisels. When you have the stencil all cut file the burr off of the edges of the letters or design with a fine file and file them at an angle so that all the edges are sharp. A practical stencil is shown at [B].
[87] Patterson Bros., Park Row, New York, carry sheet brass and copper in stock for stencils.
[88] The Brown and Sharpe Wire Gage is also used for measuring the thickness of sheet metal.
How to Use Practical Stencils.
—A short, stubby brush, called a stencil brush and made especially for the purpose is the best kind to use to stencil with. Dampen it a little and rub it on a cake of stencil ink;[89] hold the stencil down tight to the surface you are to mark and then dab—not paint—the spaces in it with the brush.
[89] Nearly every stationery store carries stencil ink and brushes in stock, or you can get them of Hammacher, Schlemmer and Co., Cor. Fourth Ave. and 13th Street, N. Y. C.
How to Make Stencil Inks.
—Dissolve 4 ounces of shellac and 1 part of borax in a little boiling water and put in enough logwood to make it red if this is the color you want it, or blue carmine if you want it to be blue. Then add enough hot water to make it about as thick as cream.
How to Use Decorative Stencils.
—Art stencils can be used with good effect for certain kinds of decorative work, but it is especially adapted for putting borders on kalsomined walls. You can cut these stencils, see [C in Fig. 82], after your own design or you can buy them already cut.[90]
[90] Write to the Frost and Adams Co., Cornhill, Boston, Mass., for a catalogue of their Art Cut Stencils. Also to Sears, Roebuck and Co., Chicago, Ills., for a list of their decorative stencils.
Mixing Colors for Stenciling Borders.
—To make the colors for decorative stencils stir a very little moresco stenciling color[91] with some hot water; be careful not to use too much color or the effect on the kalsomined or frescoed wall will be too contrasting. Beautiful colors in half-a-dozen tints can be had for this work.
[91] Made by Benjamin H. Moore and Son’s Co., 180 William St., N. Y., and sold by paint dealers generally.
CHAPTER IX
THE ART OF WORKING GLASS
One of the most fascinating of the mechanical arts is working in glass. One reason for this is because it is a substance so beautiful, so hard and so fragile that it seems to the ordinary observer to be beyond the pale of tools.
Au contraire, as the French say it, glass is easily worked if you mix a little skill with the right kind of tools and it gives me much pleasure to tell you how to do it. Further, the tools you need are few and the material is inexpensive.
What Glass Is.
—Before getting down to the processes by which glass can be worked it is a good scheme to know about the substance itself.
Hieroglyphic[92] inscriptions on the Egyptian monuments show that the art of working glass was practiced 4,000 years ago or before the Hebrew exodus.[93] Now glass is a chemical compound, the chief substance of which is sand.
[92] The early Egyptians carved the history of their arts on stone in a sign language called hieroglyphics from the Greek hieros which means sacred, and glypho which means to carve.
[93] The departure of the Israelites from Egypt under the guidance of Moses.
Common glass is made by melting sand, lime and soda together. Sand is formed of a chemical element called silica; lime is calcium carbonate and soda is sodium carbonate and there you have three chemical elements which when they are melted together make common window glass.
Glass which contains lime is called crown glass and it is this kind which is used in making one of a pair of achromatic[94] lenses. Flint glass which is the kind of glass used in making the other one of a pair of achromatic lenses contains lead instead of lime.
[94] An achromatic lens is one that is free from color.
Flint, or lead, glass melts more easily than crown, or common, glass and this is a good pointer for you to remember when you are getting glass for your glass blowing experiments. Bohemian glass, which is largely used for chemical apparatus, is made of sand, lime and potash.
Colored glass is made by putting small quantities of various substances into the melted glass. Thus oxide of cobalt[95] gives a blue color; oxide of chromium, or cupric oxide a green; one of the copper oxides gives it a red color, uranium[96] a yellow, etc.
[95] Cobalt is a metal and is usually found along with nickel.
[96] Uranium is also a metal.
How to Cut Glass.
—About the simplest and most useful process for you to know is how to cut glass.
To cut window glass you need (1) a glass cutter; (2) a drawing board and (3) a T square. There are two kinds of glass cutters on the market and these are (a) steel cutters and (b) diamond cutters.
The first kind has a little steel wheel in the end, as shown at [A in Fig. 83]. You can buy one for a quarter and it will serve all your needs very well. If money is no object you can buy a glass cutter with a diamond point such as glaziers use for about $4.00. This kind of a glass cutter has a chip of genuine diamond in a swivel end and it is a pleasure to cut glass with one of them. It is shown at [B].
Fig. 83. glass cutters
A. A steel wheel glass cutter.
B. A diamond point glass cutter.
How to Use a Glass Cutter.
—“There are tricks in all trades but ours,” said the carpenter as he drove in a screw with a hammer, and so if you will dip the steel wheel cutter into some kerosene before each cut is made you will be surprised to find how easily it cuts.
To use a diamond cutter, hold it just as you would hold a pencil and grip the three sided part with your thumb, index and middle fingers, as shown at [C]. Then place the cutter against the straight edge of your T square, press it down firmly on the glass and draw it along evenly.
To make the right kind of a cut hold the diamond at a sharp angle, that is, very slanting, and raise it slowly until a smooth, sound and clear cut is made. Don’t hold it straight up and down or you will surely spoil it, and never never cut twice over the same line.
Fig. 83c. the right way to hold a diamond point glass cutter
It takes more skill to use a diamond cutter the right way than to use a steel cutter, but a little practice will make you proficient.
Fig. 84. how to cut a pane of glass
When you want to cut a sheet of glass lay it on your drawing board with the blade of the T square on it and the head of it against the edge of the glass as shown in [Fig. 84]; hold it tight and then make a good, clean cut. You can then easily break the sheet of glass along the cut if there is enough glass on each side of the cut to get a firm hold on. If not put it into one of the notches on the shank of the glass cutter and you can then easily break it off.
How to Finish Off Glass Edges.
—When you cut a sheet of glass the edge left by the cutter will be slightly rough. To smooth it up and round off the corners rub it on a whetstone, that is any kind of a coarse stone on which you have poured a little water. A better way is to grind it on a grindstone if you have one.
How to Drill Holes in Glass.
—To drill a hole through a sheet of glass make a layer of putty ¹⁄₂ an inch thick and as large as the sheet you are going to drill and lay the glass on it.
The idea of using the bed of putty is to allow the glass to bend a little should you press down on the drill too hard. Take a Morse twist drill and, if you know how, grind it on a grindstone to a sharper point than it has when you get it; the next best thing to do is to sharpen it on your oilstone.
The best kind of a drill stock to use is an archimedian, or a reciprocating one, as shown at [B in Fig. 11], on page 29, for then the pressure on the glass is even in every direction. Set the drill on the glass at the point where the hole is to be made; hold it with the fingers of your left hand to keep it from slipping and lubricate it well with turpentine.
Work the drill at a fairly high speed and do not put too much pressure on the drill stock or you will surely break the glass.
You will find it quite hard to drill a hole less than ¹⁄₁₆ inch in diameter through ordinary glass because the drills will break and when you drill a hole over ¹⁄₈ inch in diameter you will find it a slow job because of its size, but you can drill a hole up to ¹⁄₄ inch in diameter if you go slow and are careful.
A Couple of Ways to Cut Glass Tubing.
—The First Way.
—A simple way to cut, or rather break off a piece of glass tube evenly is to make a cut all round the tube with a three-cornered file[97] and you can break it off at the line without trouble.
[97] The right name of a three cornered file is a three square file.
Fig. 85. a cutter for glass tubes
The Second Way.
—An easy and sure way to cut glass tubing off smooth is to use a gauge glass cutter;[98] this is a V steel rod with a seat on one end and a steel cutting wheel on the other. The arm of the rod holding the wheel is marked off in fractions of an inch like a rule and a stop with a set screw in it slides on this rod as shown in [Fig. 85].
[98] You can buy one of these tools of Hammacher, Schlemmer and Co., Fourth Ave. and 13th St., New York.
To use the cutter set the stop on the rod at the length you want to cut the tube; then put the rod with the cutter on it in the tube and with the seat outside; press the V rods together tight and turn it and the tube in opposite directions when it will make a good cut and you can break the tube in two easily.
How to Cut Glass Disks.
—By sawing out a round board, laying it flat on a sheet of glass and running your glass cutter around the edge of the pattern you can cut out an approximately round disk of glass.
Fig. 86. a circular glass cutter
But to cut out a perfectly round disk you must have a circular glass cutter[98a] as shown in [Fig. 86]. It has an adjustable cutter head mounted on a square rod so that the head can be turned on it. The rod is mounted on a hardwood base so that it can revolve around the latter.
[98a] You can buy one of these tools of Hammacher, Schlemmer and Co., Fourth Ave. and 13th St., New York.
After the cutter head is set on the rod for the size of the circle you intend to cut hold it down on the glass by the thumb-piece. The cutter head is then moved round in a circle and a clean cut is made after which the edge of the disk can be smoothed up.
This circular glass cutter, which is called the Little Beauty, will cut a circle 20 inches in diameter and costs about 50 cents. If you are making a frictional electric machine this is the tool you need to cut the glass plates with.
How to Bend Glass Tubing.
—It is useful to know how to bend a piece of glass tubing, especially if you are interested in chemistry and want to set up some apparatus—in fact you should know how before you ever start to experiment.
There are just two things you need to bend glass tubes with and these are (1) a Bunsen burner[99] and (2) the glass tubing, both of which you can buy of Eimer and Amend, Fourth Avenue, Cor. 18th Street, New York.
[99] Complete instructions for making a Bunsen burner will be found in The Magic of Science by the present author and published by Fleming H. Revell Co., New York.
What a Bunsen Burner Is.
—This is a burner in which a jet of ordinary illuminating gas is mixed with air, the amount being regulated by a ring which opens and closes the air holes in the burner.
A Bunsen burner makes a very hot flame because the gas in the tube moves faster than in an ordinary burner and the oxygen in the air aids the gas to burn. A plain Bunsen burner is shown at [A, in Fig. 87]. If you have no gas in your house you can use an alcohol lamp[100] which you can either buy or make for yourself.
[100] How to make an alcohol lamp out of an ink-bottle is explained in The Magic of Science.
Bending the Glass Tube.
—To bend a piece of glass tube you should have a fish tail jet set in the end of the Bunsen burner to give a wide flame like an illuminating burner as shown at B. Hold the tube over the flame of the burner, or alcohol lamp until it is heated red hot all along the place you want to bend it.
Fig. 87. kinds of bunsen burners
Now turn the tube in the flame with your fingers until it is heated evenly all around and becomes soft; take it from the flame and quickly but gently bend it as you will which you can do very easily. With very little practice you will be able to make a good smooth bend just where you want it.
How to Blow Glass
To Round the Ends of a Tube.
—When you cut a tube either with a file or a glass cutter the edge of the end will be sharp but not smooth. All you have to do to round it is to heat it in the flame until it begins to melt, when the glass will run and make a smooth edge.
To Border the Ends of a Tube.
—To border a tube means to spread the edge out a little all around so that a cork can be put in easier or a liquid poured out better.
Fig. 88. bordering the end of a tube
Take a piece of charcoal and shave it down with your knife to form a cone the size you want the border to be. Heat the end of the tube by turning it in the flame until it is quite soft and then push in the charcoal cone, as shown in [Fig. 88].
To Seal Off the End of a Tube.
—To close one end of a tube, or seal it off as it is called, heat it in a fish-tail burner just as I explained for bending glass.
When the glass begins to get soft pull the two ends of the tube apart until the walls of the tube are drawn together as shown at [A in Fig. 89]. Cut a nick in the thin solid part with a file and break it off. If you want a closed end as shown at [B] heat the end of the tube you have sealed off and press it down on a piece of iron.
Fig. 89. sealing off the end of a tube
Fig. 90. how to make a hole in a tube
To Make a Glass Nozzle.
—In setting up chemical apparatus it very often happens that a glass nozzle is needed. To make a nozzle seal off a piece of glass tube as described above and by nicking it with a file you can have the hole in the end of the tube any size you want it.
To Make a Hole in a Tube.
—To make a hole of any size in a tube, or piercing it, as it is called, you ought to have a sharp pointed flame and a blow-pipe, which is [described] farther on.
Cork up one end of the tube, heat the point, see [A in Fig. 90], where you want the hole and then stick the other end in your mouth and blow gentle puffs in it until a little bulb is formed. When the bulb is cold take a file and gently crack the thin glass and trim it away; now heat the tube around the edge of the hole again until the glass begins to run when a round smooth hole will be produced as shown at [B].
Fig. 91a. welding two tubes together. b. making a T tube
To Join Two Tubes of the Same Size.
—Put a cork into one end of one of the tubes and hold the other end in the flame as well as one end of the other tube as shown at A in [Fig. 91].
Let the ends of the tubes get hot enough to melt but not thicken; now press the melted ends together hard enough to make them stick together but not hard enough to make them form a thick ring.
Fig. 92a. a regular blow-pipe
To make a good job you should now use a pointed flame and heat the juncture all around red hot and blow into the open end of the tube to spread the glass a trifle. While you are blowing keep turning the glass in the flame to make the joint nice and smooth.
To Join One Tube to the Side of Another One.
—First make a hole in the side of the tube in the manner already described and then cork up both ends; heat the tube around the hole and one end of the other tube as shown at [B, in Fig. 91]. When they are soft press them together hard enough to make a good joint.
It is a good scheme to wrap cotton around the joint while it is still hot to anneal the glass, which means to make it less brittle by letting it get cold slowly.
Fig. 92b. cross section of a home made blow-pipe
To Blow a Bulb on the End of a Tube.
—How to Make a Blow-Pipe.
—For blowing bulbs on tubes, for flasks and the like, you need a regular glassblower’s blow-pipe in order to get a hotter flame than a Bunsen burner gives.
You can buy a blow-pipe as shown at [A in Fig. 92] for $1.50,[101] or you can easily make one as follows: get a brass tube ³⁄₄ inch in diameter and 10 inches long and drill a ¹⁄₂ inch hole in it 3 inches from one end; fit another pipe of the same size and length at an angle of about 30 degrees to the first one; put a stopcock in the latter pipe and solder it to the first pipe over the hole as shown at [B in Fig. 92].
[101] Blowpipes and bellows can be bought of Hammacher, Schlemmer and Co., Fourth Ave. and 13th St., New York.
Next take a glass tube ¹⁄₄ inch in diameter and 14 inches long and make a bend in it 3 inches from one end. Make a hole through a cork and push it over the glass tube; slip the tube into the brass pipe and force the cork into the end of the latter tight enough to hold the glass tube exactly in the middle of it.
Fig. 92c. the glass blowing arrangement ready to use
Connect the lower end of the glass tube with a rubber tube about 3 inches long to a brass tube of the same size and 8 inches long and fit a stopcock into this pipe. This completes the burner but you want to set the lower ends of the two tubes into and through the top of your table so that the stopcocks are above it and the lower ends of the tubes project below the table.
Next connect the large brass tube with a gas jet or other source of illuminating gas and the small brass tube with a foot blower or other source of compressed air as shown at [C]. The blower can be an ordinary molders’ bellows which you can buy for about $1.50, or you can make a pair, or you can buy a regular blowpipe bellows as shown at [D], which are very much better, for about $8.00.
Fig. 92d. a regular foot bellows
By adjusting the mouth of the glass tube—which is the air tube—that is, drawing it in and out of the mouth of the brass tube which is the gas tube, and by regulating the amount of air and gas, a pointed flame or a brush flame, that is, a flame of large size, can be had at the mouth of the blowpipe according to the work you are doing.
How to Blow a Bulb.
—Take a good piece of glass tube about ³⁄₄ inch in diameter and 15 inches long; draw one end out long and thin for about 3 inches as shown at [A in Fig. 93].
Fig. 93. first steps in blowing a glass bulb
A. Drawing out the tube.
B. Forming glass rings on the tube.
Then heat a small part of the tube in a large, or brush flame, turn the glass in the flame all the time until it is soft and then press on both ends to make the glass thicker at this point. Do the same thing above the ring thus formed, and so on until you have several rings of glass as shown at [B], which are thick enough to make the sized bulb you want.
Fig. 93c. making a thick ring of glass
Next heat the narrower parts marked a a a a and blow gently and press gradually on the ends to make the thick rings melt and flow together into one large ring of thick glass as shown at [C]; and in doing so be mighty careful that the walls do not cave in.
Now melt and seal off the tail and heat the whole bulb in as large a flame as you can get and at the same time turn the tube till the rings run together. At this instant take it from the flame and, still turning it, blow into it with a few little quick blasts until you get the size and shape you want as shown at [D].
Fig. 93d. last step in blowing a glass bulb
How to Etch Glass.
—There are two ways to etch glass and these are (1) with a sand blast and (2) with acid.
The Sand Blast Process.
—The process which follows is a simplified form of the regular sand-blast way of doing it, and with it you can easily make a ground glass surface or etch a stencilled name or a design on a sheet of glass.
All you need is (1) a box with a tight fitting lid 5 inches wide, 5 inches high and 10 inches long as shown at [A in Fig. 94]. Cut a hole in one end, say 4¹⁄₂ × 4¹⁄₂ inches, thus leaving a margin of wood ¹⁄₂ an inch wide all around; (2) a pound of rather coarse emery, and (3) a pound of shot.
Fig. 94a. parts of the apparatus for sand blast etching
Clean the surface of the glass you are going to etch with warm water with a little soda in it, wash it off and rub it dry. Next cut a stencil with your name on it or you can make a geometrical design by folding a sheet of paper and cutting it out with a pair of shears. Coat the glass with a thin layer of mucilage, lay the stencil on it and rub it down flat. Rub the mucilage off clean in the cut out parts with a slightly moist sponge and be sure to get it all off too.
Now cut out a piece of cloth the size of the end of the box and cut a hole in it the exact size of the hole in the box. Lay this on the end of the box with the hole in it, lay the glass over it and fix them all together tight with rubber bands as shown at [B in Fig. 94], or tie it up with string. The cloth cut-out between the box and glass will prevent the emery from sifting through.
Fig. 94b. sand blast apparatus put together ready for etching
Put the shot and emery in the box, fasten the lid on tight and then shake it hard up and down so that the emery and shot will strike the surface of the glass with as much force as possible. Keep this up for 15 minutes or half an hour when the glass will be etched deep enough.
When you open the box you will find that the particles of emery have been embedded in the lead shot and each of the latter has become a cutting tool. This process of etching can be used for metals as well as for glass.
How to Make Ground Glass.
—To make ground glass go about it as above described but in this case no stencil is needed.
The Acid Process.
—Hydrofluoric acid is made by treating fluor-spar[102] with sulphuric acid. The acid which is thus formed acts on glass by eating into it and for this reason it must be kept in either rubber, lead or platinum bottles upon which it has no effect. In etching large surfaces the acid is not put on the glass directly; because it eats so smoothly the effect is not striking enough; instead the following process is used which leaves a rough surface more nearly like that of the sand blast.
[102] Fluor-spar is calcium fluoride; you can buy it of Eimer and Amend, 4th Ave. and 18th St., New York, or of the L. E. Knott Apparatus Co., Boston, Mass.
Make a lead dish the size of the glass you want to etch and with the sides an inch high. Put about an ounce of powdered fluor-spar into the dish and pour enough concentrated sulphuric acid on it to make a thick paste.
Coat the surface of the glass with paraffin, or beeswax and rosin, and then with a steel scriber, or other pointed instrument scratch on your name or the design you intend to etch, clear through to the glass. Lay the glass with the waxed side down on the dish containing the fluor-spar mixture, as shown at A in [Fig. 95], and let it stand over night. The vapor formed by generating hydrofluoric acid in this way attacks the silica, that is the sand, of the glass with which it has a great tendency to unite, and thus the glass disintegrates or is eaten away.
Fig. 95. etching glass with acid
A. Etching a sheet of glass with fluor-spar.
B. Etching a thermometer tube with hydrofluoric acid.
The next morning when you take off the glass, scrape off the wax and you will find the name or design etched on it.
To etch the graduations on thermometers, burettes, etc., coat them with wax and scratch the lines and figures on them just as described above—but in this case you can put the hydrofluoric acid on direct as shown at [B], using a splinter of wood for the purpose.
How to Cement Glass.
—To cement glass clean the edges or surfaces to be fixed together with hot water in which you have put a little soda; dry well with a clean cloth and then be careful not to let your fingers touch the cleaned parts.
Brush over the edges or surfaces of the glass with the cement made according to the directions which follow and press and bind the parts together as tightly as possible.
To make the cement dissolve 2 ounces of the best gum arabic in some hot water and then add 1¹⁄₂ ounces of pulverized starch and ¹⁄₂ ounce of sugar and stir until they are dissolved. Heat the mixture in a pot or a tin can which sets in a larger pot or tin of water—or water bath as it is called.
When the starch gets clear take it from the fire, put in a few drops of oil of cloves to keep the cement sweet and let it get cold, when it should be about as thick as cream.
A Simple Way to Frost Glass.
—Make a saturated solution of alum water, which means to dissolve as much alum in hot water as possible.
Lay the glass on a perfectly level table and pour on as much of the alum water as you can without its running off and let it cool slowly, when the alum will cover the glass with fine crystals. This is a good substitute for ground glass.
A cheap frosting for windows can be made by dissolving Epsom salts in hot water and then mixing it with a clear solution of gum arabic.
Substitutes for Glass.
—There are a number of substances that can be used instead of glass. In some cases a substitute is better than glass but generally they are used because they are cheaper.
Mica.
—This mineral, which is also but wrongly called isinglass, is found in Farther India; it is a silicate and can be split into thin sheets; in color it ranges from colorless to a jet black and from the transparent to the translucent. It is useful in many ways because it is fireproof.
Gelatine.
—Gelatine is obtained from the skins, hoofs and horns of animals. Isinglass is a nearly pure gelatine and is a white, tough, partly transparent substance which is obtained chiefly from the air-bladders of fish.
To make sheets of either gelatine, or isinglass, dissolve some of the finest glue, or isinglass—the latter is the best—in enough hot water so that it will form a flexible solid sheet when it is cold.
While it is still hot strain it through a piece of cheese cloth; this done, grease a clean sheet of glass and build up the edges with some putty; warm the glass and pour on the gelatine to a thickness of ¹⁄₈ inch. Now lay another greased and hot sheet of glass on top of the gelatine and let it stay there until it is cold. The sheets of gelatine can be given any color by adding a little aniline to the gelatine while it is hot.
How to Silver a Mirror.
—While it is much cheaper to buy a mirror than it is to make one still there are times when it is useful to know how to make one.
As you know, a mirror is a sheet of clear glass free from air bubbles and upon the back of which is a film of silver. The silver bath is made by mixing a weak solution of silver nitrate with ammonium hydroxide until the solution is clear and then adding a little caustic potash to it. This done, put in a few more drops of ammonia and finally a very little glycerine.
Now float the glass on this mixture when the surface will soon be coated with silver. When the film is thick enough take the glass from the bath, wash the film of silver on the back of it with clean, cold water, dry and varnish it and your mirror is done.
CHAPTER X
TOYS FOR THE KIDDIES
If there is as much pleasure in giving as there is in receiving you can get twice as much pleasure out of making toys with your own hands and giving them to your little brothers and sisters—if you have any, and if you haven’t, then I’m truly sorry for you.
Since you know how to use wood and metal working tools it will be easy for you to make any and all of these toys I have described in this chapter and some of them are quite useful too. And when you are making them let the little folks watch you for this will please them greatly and make them doubly happy.
Now some grown-ups don’t know it but however small a kiddie is he or she likes to play with things that look like those the older folks work with. Of course all toys cannot be of this kind for some of them are made to be funny and others are made to be lifelike, but these are the three chief kinds of toys.
How to Make a Policeman’s Puzzle.
—Get two strips of wood ¹⁄₄ inch thick, ¹⁄₂ an inch wide and 11 inches long and cut handles on one end of each strip. Saw with your scroll saw out of ¹⁄₈ inch thick wood, two policemen 6 inches high and also one Baxter Street clothier of Semitic persuasion, 3 inches high as shown in [Fig. 96].
Pivot the leg near the foot of each policeman to the ends of both of the strips by driving a couple of brads through and into them and then nail the Israelite fast to the top strip with a couple of brads. Now when you pull the strips apart one of the long arms of the law will crack Ikey on the cranium and when the strips are pushed together again the other minion of authority will bounce his club on the place where his brains ought to be. A little red and blue water color will add to the realism of the toy.
Fig. 96. a policeman’s puzzle, or now will you be good
How to Make an Automobile Truck.
—This little toy will bring a lot of unalloyed joy to any tiny, weentie fellow and it’s easy to make, too.
Cut out a board for the bottom ³⁄₄ inch thick, 4¹⁄₂ inches wide and 14 inches long; trim down one end of it so that it is 2 inches wide in front as shown at A [Fig. 97]. Bore a ¹⁄₄ inch hole 2³⁄₄ inches from the front end.
Saw off a block of wood 1 inch square and 2¹⁄₂ inches long—this is to brace the seat with—and glue this block across the body 6¹⁄₂ inches from the back as shown by the dotted line in [Fig. 97]. Make a seat of a board ¹⁄₄ inch thick, 1¹⁄₂ inches wide and 3¹⁄₂ inches long and glue or nail it to the block.
| C—THE HOOD | B—SIDE VIEW |
| TOP VIEW |
Fig. 97. plans for the automobile truck
To make the body or box, cut out two strips of wood ¹⁄₄ inch thick and make one 2 inches wide and the other 2¹⁄₂ inches wide and 4¹⁄₂ inches long for the front and back, and two strips of wood 2 inches wide and 6³⁄₄ inches long for the sides. Nail one of the short strips on the bottom close up to the seat and the blocks of wood it rests on and nail the side strips on the bottom.
Next round off the lower edge of the short board that is left; set it in between the ends of the sideboards and drive a brad through each of the sideboards and into the tail-board near the bottom; this brings the tail-board so that it can be closed up or let down as the side view at [B] shows.
Saw off two ³⁄₄ inch square blocks and have both of them just a shade over 4¹⁄₂ inches long and these are for the axles. Nail one fast near the rear of the bottom 2 inches from the back end, and nail the other one fast to the front of the bottom 1 inch from the end.
Fig. 97d. the automobile truck ready to run
Make a hood out of a block of wood 1³⁄₄ inches wide and long and 2 inches high and bevel off the top as shown at [C]; nail this to the bottom in front as shown in the top and side views. For the steering wheel saw out a wheel ¹⁄₄ inch thick and 1¹⁄₂ inches in diameter.
The last thing to do is to saw out four wheels ¹⁄₄ inch thick and 2³⁄₄ inches in diameter; drill a ¹⁄₈ inch hole in the exact center of each wheel and screw it on the end of the axle with a 1 inch long, round head, wood screw. Paint the automobile a bright red when it will look like [D] and run like a fire engine.
How to Make a Swell Coaster.
—This is a practical toy that every little tot will like immensely. It is just as simple as the automobile but it must be made very much stronger.
| A—TOP VIEW |  | ||
 | |||
 | D—STEERING HANDLE | ||
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| C—SIDE VIEW | B—AXLE SUPPORT | ||
Fig. 98. plans for a swell coaster
Get a board, hardwood is the best, ⁷⁄₈ or 1 inch thick, 5³⁄₄ inches wide and 14 inches long and saw it out so that one end is 2¹⁄₂ inches wide as shown at [A in Fig. 98]; bore a hole 1 inch in diameter in the front end and ³⁄₁₆ inch holes across the back at the places marked with circles.
Next make the rear axle support and for this saw out of a 1 inch thick board a piece 4 inches wide and 7 inches long and saw out of one end of it a piece 2 inches square. Take your brace and bit and bore a ¹⁄₄ inch hole through the hangers as shown at [B].
Screw this support to the seat across it 1¹⁄₂ inches from the rear end. Brace the support by screwing an angle brace, as shown in the side view [C], to it and the seat. This done make the steering handle, and for it you want to use a stick of hardwood 1 inch thick, 2 inches wide and 15 inches long; saw a piece out of one end 1¹⁄₈ inches wide and 2¹⁄₂ inches deep for the axle support for the front wheel; saw the other end down until it is 1 inch wide and 6 inches deep.
Fig. 98e. the coaster ready to ride on
Round off this smaller end for the handle, as shown at [D], and bore a ¹⁄₂ inch hole close to the end for the handle bar. Slip the rounded end through the hole in the front part of the seat, drive a nail through it just above the seat and glue in a piece of wood ¹⁄₂ an inch in diameter and 6 inches long, for the handle bar.
Saw out three wheels each of which is 4 inches in diameter, bore a ¹⁄₄ inch hole in the center of each one. Set one of the wheels between the hangers of the steering handle, slip a bolt through them and screw on a nut.
Push a bolt through each of the other wheels and through a hanger of the axle support and screw on a nut, when the coaster is ready to run, as shown at [E]. A coat of bright paint will make it more attractive but it won’t run any better.
How to Make a Nifty Wheelbarrow.
—This is a cute wheelbarrow and will tickle any little choptie ’most half to death and you can make it in no time.
Get two sticks of wood ³⁄₄ inch square and 24 inches long and round off one end of each one about 3 inches down for the handle. Next bore ¹⁄₂ inch holes half way through in the other ends of the sticks 4 inches back for the axle; bore two more ¹⁄₂ inch holes 6¹⁄₄ inches back of the first two, and finally 5³⁄₄ inches back of the last ones bore two more ¹⁄₂ inch holes, as shown at [A in Fig. 99].
This done cut off four sticks ¹⁄₂ an inch in diameter—or ³⁄₄ inch square ones will do—and make one of them 4¹⁄₂ inches long; the next one 6³⁄₈ inches long, the third 8 inches long, and the last one 10¹⁄₂ inches long.
Out of a board 1 inch thick saw a wheel 5 inches in diameter and bore a hole in its center ¹⁄₂ an inch in diameter. Smear some glue on the middle of the shortest stick and slip the wheel on it so that it is exactly in the middle.
Make the body, that is the box, of the barrow of wood ¹⁄₄ inch thick and have it 4¹⁄₄ inches wide at one end, 6¹⁄₄ inches wide at the other end, 5 inches high and 7 inches long. Through the middle, but a little toward the back and near the upper edge, bore two holes a shade larger than ¹⁄₂ an inch in diameter and slip the third longest stick through the holes in the body; drive a brad through the stick on each side of the body to keep the latter from slipping from side to side, but it must swing easily on the stick.
A—TOP VIEW OF WHEELBARROW
B—SIDE VIEW
C—WHEELBARROW COMPLETE
Fig. 99. a, b. plans for the nifty wheelbarrow, c. the barrow ready to wheel
You are now ready to assemble the wheelbarrow and if you intend to paint it you must do so before you put it together. To assemble it smear glue on the ends of all the cross-sticks, except the one with the wheel on it for this one must revolve, and drive on the handles, being careful that the axle of the wheel does not bind. A side view of the wheel barrow is shown at [B].
When it is done, see [C], you will see that however high or low the handle-bars are held the body always sets level and if it is a good idea for a toy why wouldn’t it be a good idea for a full grown wheelbarrow?
How to Make a High-Low Swing.
—Here is a peace promoter and a queller of disturbances wherever there are very little kiddies around. It is an indoor swing that can be hung from the top of a door-case. Further, though it may look a little complicated in the drawing, it is simplicity itself.
First take the seat and for this, as for all of the wood for the swing, use ¹⁄₂ inch thick stuff. Cut out two side bars 1 inch wide and 13 inches long and drill a ³⁄₈ inch hole in the end of each one. Across these bars nail four cross bars 2 inches wide and 14 inches long as shown at [A in Fig. 100].
Next make the sides of the swing and from each of these saw off two strips 1 inch wide and 13 inches long as shown at [B]. Bore a hole in each end of both sticks to match the holes in the side bars of the seat and then bore two ¹⁄₂ inch holes in both sticks and have each hole 2¹⁄₂ inches from the end.
Saw off two strips of wood ¹⁄₂ inch thick and 1 inch wide for each side, cut down and round the ends, smear glue on them and drive them into the cross-sticks. The backs of the swing, as you will see at [C], are made exactly like the sides except that they are 14 inches long, and finally a single bar 1 inch thick and wide and 14 inches long with a ¹⁄₂ inch hole in each end goes across the front of the swing to keep the little fellow from falling out.
 |  | ||
| A—THE SEAT | B—THE SIDES | ||
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| C—FRONT BAR | |||
Fig. 100. plans for the high-low swing
Now get two pieces of good ³⁄₈ inch thick manila rope about 10 feet long; double each piece in the middle and pass one end through the hole in the front bar, thence through two holes in the side-strips and finally through the hole in the cross-bar of the seat and then knot it.
This done pass the other end through the holes in the cross-strips of the back, then through the holes in the cross-strips of the side and last of all through the cross-bars of the seat. Fix the other piece of rope the same way and swing is done, as shown at [D].
Fig. 100d. the swing ready to swing low, swing high
All you have to do now is to loop the top of the ropes over a couple of hooks screwed into the top of the door-case, put the little tot in and give him or her a swing.
How to Make a Stick Horse.
—This is a great improvement over riding a broomstick because it doesn’t take so much imagination to change it into a runaway horse.
Saw out of a board 5 inches square the head of a fiery steed as shown at [A in Fig. 101] and paint it a dapple-gray, with a mane on its neck to look like a real pony. Make a rein of webbing and then nail the head on a stick ³⁄₄ or 1 inch square and 3 feet long for the rider to straddle.
THE HEAD OF THE HORSE
THE STICK HORSE COMPLETE
Fig. 101. ride a stick horse to banbury cross
Make an axle of a stick 1 inch square and 4 inches long; whittle the ends down until they are ¹⁄₂ an inch in diameter and nail the axle to the free end of the long stick. Saw out a pair of wheels of ³⁄₄ inch thick stuff, 4 inches in diameter and bore a ¹⁄₂ inch hole through their centers.
Slip a wheel over each end of the axle and drive a thin nail through each end to prevent the wheels from coming off, and it will be fit and ready to ride as shown at [B].
How to Make a Pony and Cart.
—If this little pony and cart are to be played with in the house you can make it the size marked in [Fig. 102] but if it is to be used out-of-doors then you should make it twice the size.
Get a nice smooth board ¹⁄₂ an inch thick, draw on it a horse, at least as good as the one shown in the picture, and then saw it out. Paint it any color but red or green, for ponies, even in little picture books, are never of these colors.
Make a frame 1⁵⁄₈ inches wide and 4 inches long by nailing two strips of wood ¹⁄₂ an inch square with a block of wood ¹⁄₂ an inch square and 1 inch long between them. This leaves an opening ¹⁄₂ an inch wide and 1³⁄₄ inches long as shown at [A]. Saw out of a piece of ³⁄₈ inch thick wood a wheel 1 inch in diameter and drill a ¹⁄₁₆ inch hole through its center. Set the wheel in the opening and drive a wire nail through the frame and the center of the wheel for it to run on. This done nail, glue or screw the horse to it as shown at [B].
Make the cart next, see [C], which is simply a box made of ¹⁄₄ or ³⁄₈ inch stuff, 3 inches high, 4 inches wide and 6 inches long. Nail a strip of wood ¹⁄₂ an inch square and 4¹⁄₈ inches long on the bottom and in the middle of it. Saw out a pair of wheels 2⁵⁄₈ inches in diameter and screw them to the ends of the strip of wood so that they can turn freely.
Next make the shafts; these are formed of two strips of wood ¹⁄₄ inch thick and about 5¹⁄₂ inches long. Nail the ends of these to the front end of the cart in the middle and at a distance apart so that the horse will just slip in between them.
 | |
 | COMPLETE |
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| FRAME FOR THE WHEEL | |
| PONY | |
| CART | |
 | |
Fig. 102 a, b. plans for a pony and cart. c, d. the pony and cart when done
Glue, or otherwise fasten the shafts to the horse, as shown at [D], and you can then show your little brother how to play with it, but don’t break it before you give him a chance to play with it too. The finished pony and cart will then look like the picture.
How to Make a Life-like Goose.
—Nearly all geese, including goslings, are lifelike unless they are being made ready for the pot but this gray-goose is lifelike in that her head moves out from and back toward her body when she is drawn over the floor by a string.
Fig. 103. how the life-like goose is made
A. The size of the board for the body.
B. The size of the board for the head and neck.
C. The crank shaft which makes the goose life-like.
Get two pieces of thin wood ¹⁄₄ inch thick, 3¹⁄₂ inches wide and 6 inches long; draw the outline of a goose’s body on one of them, as shown at [A in Fig. 103], and then fasten them together with a couple of brads. Saw them out and drill a ¹⁄₁₆ inch hole through them in the center of the circle which is the wheel; also drill, or bore, three ¹⁄₄ inch holes at the points near the edge of the body as shown by the larger circles.
On a board ¹⁄₄ inch thick, 2³⁄₈ inches wide and 5¹⁄₄ inches long draw out the head and the neck of a goose, as shown at [B], saw it out and drill a ¹⁄₁₆ inch hole near the end of its neck. Now paint the bird’s body and the anterior part of its anatomy—by which I mean its head and neck. Saw out two wooden wheels 2 inches in diameter and drill a ¹⁄₁₆ hole in the center of each one.
Cut off a piece of iron wire ¹⁄₁₆ inch thick, slip it through the hole in the goose’s neck and bend the wire on both sides of it to form a crankshaft as shown at [C]. The next move is to put each end of the wire through the small hole in the body, then force a wheel on each end of the wire tight and bend up what is left of the latter.
Fig. 103c. goosie, goosie gander, where shall i wander
Make three pins of wood ¹⁄₄ inch in diameter and ⁷⁄₈ inch long; smear some glue on the ends and drive them gently through the holes; these pins will keep the boards which form the body the right distance apart and the pins in front also act as a guide for the goose’s head. When finished it will look like [C]. Now when a string is tied to the front part of the goose’s body and your little sister (or you) pulls it over the floor, the goose will run its head to and fro and forth and back in a most real and life-like fashion.
How to Make a Dancing Sambo.
—Here is a chance for you to get in your fine work with your scroll saw and to do a bit of wood carving at the same time if you want to.
Fig. 104a. the dancing sambo
Saw out, or carve out, or both, the head and body of a black rascal named Sambo, and make them of a single piece of wood; saw out a pair of arms and legs but make each one of the latter in two parts and joint them at the knees as shown at [A in Fig. 104].
Fasten the arms and legs to the body with pins so that they will swing freely. The figure should be about 6 inches high and painted in 3 or 4 bright colors. When you have it done fix the end of a wire ¹⁄₁₆ inch in diameter and 5 inches long, firmly into the back of Sambo’s body.
Make a box 3 inches wide, 3 inches high and 6 inches long; bore or cut a hole ³⁄₄ inch in diameter in one end; turn it upside down and drill a ¹⁄₁₆ hole through the middle of the top and drill a ¹⁄₁₆ inch hole through both sides 2 inches back from the large hole in it as shown at [B].
Fig. 104b. the mechanism of the dancing sambo
Cut off a strip of wood ¹⁄₂ an inch square and as long as the box is wide, drill a ¹⁄₁₆ inch hole through it and glue it inside the box so that the hole in the strip and the one in the top of the box will be in a line.
Now cut off a strip of hardwood ¹⁄₄ inch thick and 3¹⁄₂ inches long for the lever and drill a ¹⁄₁₆ inch hole through it 2 inches from one end; slip the lever through the hole in the end of the box with its end under the cross-bar; pivot the lever by running a wire through the hole in it and the sides of the box as shown at [B].
Slip the wire which is fixed to Sambo through the hole in the top of the box and on down through the hole in the cross-bar so that its free end rests on the end of the lever. This is all there is to the working mechanism of Sambo.
By working the end of the lever with your fingers as though you were sending a telegraph message, as shown at [A], the small time Ethiopian will execute all sorts of fancy dance steps and cut up antics that will keep the children, and the grown-ups too, in great good humor for a long time.
By working the lever cleverly you can give the darkey distinctive characteristics that not even a member of his own race ever possessed.
Fig. 105a. the wireless pup. the slot in the floor of the dog house
How to Make a Wireless Pup.
—This is a most remarkable bull-pup for he will jump out of the kennel when you or any one else calls him, when you clap your hands or on any other occasion when a loud noise is made.
Always make a dog-house for a pup before you catch him so that when he gets home he’ll know he’s there. Use smooth ¹⁄₂ inch thick pine boards for the house and cut out a piece 7 inches wide and 8 inches long for the floor. Cut a slot clear through the board 1³⁄₄ inches from one end and parallel with the edge of the back and have it ¹⁄₂ an inch wide and 1¹⁄₄ inches long; then on each end of the slot cut a groove ¹⁄₂ an inch long and ¹⁄₄ inch deep as shown at [A in Fig. 105].
Fig. 105b. the back end of the dog house
Cut out two pieces for the sides of the house 4 inches wide and 8 inches long and screw them to the floor. Now bevel off the top edges of the sides with a plane to allow for the slope of the roof but before you put it on you must install the wireless apparatus that makes the pup jump out of the dog-house. Make a back out of a board 7 inches square as shown at [B].
This apparatus consists of five chief parts and these are (1) a spanker; (2) a solenoid; (3) a stiff piece of clock-spring; (4) a telephone transmitter and (5) two or three cells of dry battery.
Fig. 105c. the spanker with electric solenoid control
The spanker, so called because it spanks the pup out of his kennel, is shown at [C]; it is simply a strip of wood ¹⁄₈ inch thick, 1 inch wide and 3¹⁄₂ inches long. Tack, or otherwise fix, a piece of tin to one side of it to form an electrical contact; cut a ³⁄₈ inch hole in the middle of it and then drive a brad in each edge near one end. The spanker sets in the slot in the floor and the brads rest in the grooves and serve as pivots.
A solenoid is merely an electromagnet with a loose iron core in it. Make a cardboard spool 1¹⁄₄ inches long and 1¹⁄₂ inches in diameter and have the hole in it ⁷⁄₁₆ inch in diameter; wind it full of No. 20 or 22 double cotton covered magnet wire and your solenoid is done. An iron bolt ³⁄₈ inch in diameter and 1¹⁄₄ inches long makes a good plunger, as the loose iron core is called. Slip it through the hole in the spanker and screw the solenoid to the inside of the back of the house as shown in the cross section drawing at [D].
Fig. 105d. cross section side view of the wireless pup ready for action
Make a contact plate of a strip of tin or sheet brass and screw this to the floor back of the spanker so that when the plunger is drawn into the solenoid and the spanker is back as far as it will go the plate will come in contact with the tin on the spanker. Put a stop in front of the spanker to prevent the latter from falling too far forward.
Fig. 105e. the front end view of the wireless pup house
Next get a strong, stiff piece of clock-spring, punch two holes in one end and screw it to the back of the house near the top, with the free end of the spring pressing out the spanker. Fasten by means of hangers, or otherwise, an ordinary telephone transmitter to the roof of the house as shown at [D]. Now make the front of the house and cut 4 × 5 opening in it for the pup to get in and out, and a hole 1¹⁄₂ inches in diameter, as shown at [E], so that when you put the front on, the hole will be directly over the mouthpiece of the transmitter.
Before putting on the front connect up the apparatus as shown at [D], that is, connect one of the wires of the transmitter to the contact plate; join the other wire of the transmitter to the battery; lead one of the wires of the solenoid to the tin on the spanker. When these connections are made the circuit will be complete if a battery is connected in and the spanker is pushed back. Now put on the front of the house and then make the pup.
Fig. 105f. when you call the wireless pup or clap your hands he comes out of his dog house in a hurry
Saw the body of the pup and his legs out of separate pieces of wood and glue them together. He should be 2³⁄₄ inches high and 5 inches long when done and he must slide easily on the floor. See [F, Fig. 105].
The action of the wireless pup is like this: You push the pup into the house and back against the spanker as far as he will go; this presses the spring back and at the same time makes connection with the contact plate which closes the circuit.
The current from the battery then flows through the solenoid and transmitter and this magnetizes the iron plunger core and holds the spanker back against the force of the spring.
If now you call loudly, or clap your hands, the carbon granules in the transmitter will vibrate and this will suddenly weaken the current, and, hence, the magnetism of the solenoid. The instant the magnetic pull of the solenoid is weaker than the spring the latter will force the spanker against the posterior end of the pup’s anatomy and boost him out of his kennel.
CHAPTER XI
HOME MADE MUSICAL INSTRUMENTS
There is music in everything if you only know how to get it out without cracking it. When a small boy beats a pie-pan with a stick, or drums on a wooden fence he is making music, only the neighbors won’t believe it.
This is because he sets up the same note in succession and after a while the constant repetition of this single note gets on a grown-up’s nerves, especially if he is writing a book; hence he thinks the sounds are noise but it is really music of a bombastic[103] order.
[103] The gong, drum, bell, and cymbals all set up sound by concussion and these are called bombastic instruments.
By this I mean that what we call noise is sound set up by uneven air waves[104] in time and volume while music is made by a tone, or tones, of even air waves. Any musical instrument that produces sound by shock, or concussion as it is called, is said to be bombastic.
[104] For the theory of air waves and sound see The Magic of Science by the present author, published by Fleming H. Revell and Co., New York.
When a bombastic instrument is played alone the sounds set up by it are not very sweet or musical but if you will use a set of eight of them, or octave as it is called, and tune them so that the pitch—which is the number of air waves that are produced and heard in a second of time—of each one is a note higher than the one before it and then make first one and the other vibrate you will produce pleasing tones, and by combining these tones properly you will have a resemblance of what we call music.
The Musical Coins.
—How to Make Them.
—A simple and very pleasing way to show that there is music even in cold brass is to take a piece of sheet brass, or, better, sheet steel, about ¹⁄₁₆ inch thick and scribe on it with a pair of compasses eight circles whose diameters range from 2 inches to 3 inches.
Fig. 106a. the musical coin
Saw them out and file them down so that each one will ring out a whole number, as it is called in physics; that is, if the largest and deepest toned coin, or disk, makes 250 vibrations a second, the next one must make 500 vibrations a second, the next 750 and so on until the smallest and highest pitched coin will make 2000 vibrations a second.
When each coin rings out its whole number, or nearly so, you will have what is known as a harmonic series. Now saw notches in the edges of each one as shown at [A in Fig. 106] and then file them until the tone of each one is just right.
How to Play Them.
—To play a tune with the musical coins spin them on the top of a table—a marble top table is the best—and as each coin dies down[105] and its edge strikes progressively against the surface of the table it will ring out in a clear, loud tone.
[105] If you will look closely at the spinning coin you will see that when it spins fast at first the axis about which it rotates is its diameter and that the coin stands upright. As the coin commences to die down the axis about which it spins gradually begins to shift from the diameter to the center of the coin until finally at the finish the coin is spinning directly about its center. This motion is the same as the processional motion of the earth.
Fig. 106b. how to hold the musical coin to spin it
The coins should be laid in a row on the table and whatever note you want to ring out pick up the coin which will produce it, hold it as shown at [B], and give it a little spin. You can soon learn to spin them with either hand and keep two or more of them going at the same time, when you will have that agreeable combination of tones that is known in music as harmony.
The musical coins are easy to learn to play and at a little distance off they look like real coins and are a very pleasing novelty.
The Musical Tomato Cans.
—How to Make Them.
—The musical tomato cans make a bombastic instrument—very bombastic I should say. Be that as it may, get eight tomato cans, soak the labels off carefully and keep them. Next melt off the tops of the cans and paste the labels on them again. Set each can on a piece of felt as shown in [Fig. 107].
Fig. 107. the chopin tomato can
Now by pouring water in the cans you can tune them so that each one will send forth a whole number note and all of them together will give the notes in the regular order of an octave. You do not need to put any water in the first can but use this one for the fundamental note, that is the note on which the chord is formed.
Make a couple of mallets, as the sticks to beat the cans with are called, of a pair of sticks about as thick as a lead-pencil and twice as long and glue a wooden ball ⁵⁄₈ inch in diameter on one end of each one.
To Play the Tomato Cans.
—When you have tuned the cans set them in a row on a piece of felt, or a couple of thicknesses of thick woolen cloth will do, and with a mallet in each hand tap them softly.
While some folks who have no ear for melody, harmony and dissonance[106] may say that both the instrument and the performer ought to be canned still the instrument is a great one to play Chopin’s[107] funeral dirge[108] on. Undertakers are crazy about the musical tomato cans.
[106] These are the three chief factors that make up the various combinations of tones which we call music.
[107] Chopin (pronounced Sho′-pan) was a Polish musical composer.
[108] A dirge is a tune expressing grief and mourning.
The Musical Glasses.
—How to Make Them.
—Different from the tomato cans, the musical glasses make about the sweetest music ever heard. To make a set get eight very thin glass goblets and mount them on a board 12 inches wide and 2 feet long. An easy way to do this is to fasten the foot of each goblet down with a couple of thin strips of tin or brass placed across it and screwing the ends of these to the board as shown in [Fig. 108].
To tune the glasses pour water in them until each has exactly the right pitch and together they form an octave. When you have learned to play simple tunes on an octave of musical glasses you can build up the set to 22 glasses or three octaves, which will give you enough notes to play almost any of the popular airs.
Fig. 108. the musical glasses
How to Play the Glasses.
—Before starting in to play moisten the rims of the glasses and rub your fingers with water in which you have put some vinegar, or better, a little acetic acid,[109] until they feel quite rough.
[109] This is the acid contained in vinegar that gives it its value.
Now when you lay the tips of your fingers flat on the rim of a glass and rub them around it, the friction between the skin of your roughened fingers and the edge of the glass will set the latter into vibration and a wonderfully sweet tone will be sent out. By varying the pressure of your fingers on the glasses you can produce a very beautiful tremolo effect.
It is a good scheme to put a few drops of acetic acid into each goblet so that just as quickly as the volume of sound begins to fall off you can dip your finger tips into whatever glass they are nearest to and so increase the friction between them and the glass.
If you can play a set of musical glasses well your services will be in demand for all kinds of entertainments.
The Tubular Harp.
—How to Make It.
—This easily made instrument gives out tones very much like those of the musical glasses but they are much deeper and louder.
Fig. 109 a, b. the harp of a thousand thrills
To make this harp you will need 12 feet of ¹⁄₂ inch bell-metal[110] tube—brass tube will do but it is not as good—and cut it into eight pieces; saw off the first tube 2 feet long and cut off each of the other pieces ¹⁄₂ an inch shorter than the one before it. Cylindrical sticks of wood can also be used for the tubes.
[110] Brass and bell metal tubing can be bought of the U. T. Hungerford Brass & Copper Co., 89 Lafayette St., New York.
Get two strips of wood 1 inch square and 3 feet long and screw them together as shown at [A in Fig. 109] with a couple of thumb screws; this done bore eight ¹⁄₂ inch holes in the sticks every 4 inches apart and smooth them out with a half-round file.
Glue a strip of cloth on the side of each strip that is bored out, set each tube with the middle in the groove so that they grow shorter in steps and screw the strips together tight with the thumb screws to hold the tubes in securely as shown at [B].
Fig. 109c. how to play the harp
To tune the tubes saw off and file off the end of each tube until it gives forth the proper note. When you have tuned them make a stand to hold the instrument and this can be of either wood, or metal tubing if you want the harp to look nice and you don’t care about the expense. The harp is shown complete at C.
How to Play the Harp.
—When you have made the stand get a pair of old gloves and cut off the fingers; powder some rosin and rub it well into the palms of the gloves.
This done, put on the gloves, grip the top of the tube and draw your hand slowly down toward the sounding board, as shown at [C], and a beautiful tone will be emitted. Not only does the tube vibrate to make the sound but as it is hollow it acts as a resonator, that is, the sound will set up sympathetic vibrations in the tube which will reënforce the simple vibrations of the tube both in strength and quality.
By waving your finger over the top of the tube while you are playing it with the other hand a tremolo effect can be produced that is very beautiful and if you are versatile you can make it sound almost like a human voice.
The Musical Push Pipe.
—How to Make It.
—This musical instrument is an organ pipe but it is played like a slide trombone, that is by pushing in and pulling out a slide that fits inside of it.
Spruce is the best wood to make the organ pipe of but you can use any other kind you have at hand. Saw off four strips of wood ¹⁄₄ inch thick and 16 inches long and have two of them 3 inches wide and the other two 2¹⁄₂ inches wide, as shown in [Fig. 110]. Saw off one of the 3 inch wide boards so that it will be 12¹⁄₄ inches long and plane down one end to a sharp edge as shown at [B].
Take another board ¹⁄₂ an inch thick and make it 2¹⁄₂ inches high and 3 inches wide as shown at [D]. Cut out a board for the end ¹⁄₄ inch thick, 2¹⁄₂ inches wide and 2¹⁄₂ inches long and bore a ¹⁄₂ inch hole in it as shown at [E].
THE PUSH
THE PIPE
BACK BOARD
TOP FRONT BOARD
LOWER FRONT BOARD
LIP
SIDE BOARDS
END
MOUTH PIECE
Fig. 110. parts of a musical push pipe
As you supply this pipe with air by blowing in it, take a common thread spool and trim down one end of it as shown at [F] so that you can get it into your mouth; then glue the large end over the hole in the bottom board. Next glue the sides together to form a square tube and make and glue into the lower end a three-cornered piece of wood 2 inches wide, 3 inches high and 2¹⁄₈ inches thick as shown at [G]. This will bring one of its sharp edges just under and very close to the sharp edge of the short side of the pipe.
Glue the thick piece of wood shown at [D] to the lower end of the pipe so that it leaves a ¹⁄₄ inch space between its top edge and the sharp edge of the short side of the pipe. Finally glue the mouthpiece in the lower end of the tube and this part of the push pipe is done.
If now you will place your hand over the open top of the pipe and blow through the mouthpiece, a soft note like that of a steamboat whistle will issue from it. To play a tune on the pipe it must have a range of an octave but if it will sound an octave and a half you can play many of the popular airs on it.
To do this fit the organ pipe with a movable stop, or push, which slides in and out of the pipe. Make this push of two strips of ¹⁄₈ inch thick wood, 2¹⁄₂ inches wide and 12 inches long; screw one end of each of these boards to a block of wood the size of the top of the organ pipe and screw a knob—the head of a clothespin will do—on it in the center for a handle. The stop, or slide, will of course be open on two sides and must slip snugly but easily in the pipe.
To Play the Push Pipe.
—If now you will blow through the mouthpiece and slide the stop in and out various tones and semi-tones will be produced. It takes very little practice to learn just where to stop the slide to make a given note—that is if you are at all apt in playing musical instruments. A push pipe[111] is just the thing for a black-face musical act.
[111] A push pipe can be bought for $4.00 of the L. E. Knott Apparatus Co., Boston, Mass.
Fig. 110j. how the push pipe is played
The Curious Xylophone.
—How to Make It.
—This instrument, which is pronounced zil-o-fon´, is cheap to make or buy[112] and is easy to learn to play.
[112] Can be bought of any dealer in musical instruments or of the L. E. Knott Co., Boston.
To make one cut off fifteen bars of a stick of maple ¹⁄₂ an inch thick, ⁷⁄₈ inch wide and make the longest one 5 inches. To get the right lengths of all the others you will have to saw them off a little at a time and try them out for tone, because any variation in thickness will make a difference in the length of them. Hence the above rule-of-thumb method for determining the sizes of them.
Drill a ¹⁄₁₆ inch hole through both ends of each bar and string them on a wire to keep them in place. Make two rolls of straw ³⁄₄ inch in diameter and 20 inches long; fix the ends of these rolls on a board as shown in [Fig. 111] and lay the maple bars on them when they are ready to be played on.
How to Play the Xylophone.
—The xylophone is played with a pair of hammers. To make the latter cut off two sticks ¹⁄₄ inch in diameter and 8 inches long; get or turn two wooden balls 1 inch in diameter; bore a ¹⁄₄ inch hole in each one and glue in one of the sticks.
Fig. 111. a xylophone. the bars are made of wood
Take a hammer in each hand and hold it loosely; stand over the xylophone so that the sticks of the hammers are parallel with and about 6 inches above the bars of the xylophone and with the ball ends in the middle of the bar it is over. Now pound the bars for dear life and the faster the tune the more musical it will sound. For this reason pieces like the Circus Life Gallop are especially adapted for the xylophone.
The Peculiar Tubaphone.
—How to Make It.
—By using brass tubes, or better, tubes made of bell metal, you can have a xylophone of another order. Use tubing ³⁄₄ inch in diameter and have the first one 5 inches long for the fundamental.
Keep on sawing them off and filing them down until you have them all done and all in tune. Make a wooden frame of ¹⁄₂ inch stuff and have the bottom 2 inches wide at one end, 4 inches wide at the other end and 17 inches long.
Fig. 112. a tubaphone. the bars are made of metal tubes
Saw off two strips of wood ¹⁄₂ an inch thick, 1 inch wide and 17 inches long. Bore fifteen ³⁄₄ inch holes 1 inch apart measured from their centers in them; glue a strip of felt or thick cloth to the wood in each one and slip the tubes in the felt lined holes as shown in [Fig. 112].
How to Play the Tubaphone.
—To play this peculiar instrument use a couple of felt covered mallets; these can be made by winding a little ball of string around one end of each stick which should be about ¹⁄₄ inch in diameter and 8 inches long, and then covering it with felt. Beat the tubes with the felt mallets in exactly the same way you do when you play the xylophone.
The Cathedral Chimes.
—How to Make Them.
—This is one of the easiest musical instruments to make and the music produced by it is impressive in its tone and depth.
To make it saw off a board, ³⁄₄ or ⁷⁄₈ inch thick, about 12 inches wide and 22 inches long and screw a block 1 inch square to each corner for it to rest on. Get eight binding posts[113] of the size shown at [A in Fig. 113]; drill eight ¹⁄₈ inch holes in the board, 4 in a row with the holes 5 inches apart and have the rows also 5 inches apart, and then screw a binding post into each hole.
[113] These can be bought of the Manhattan Electrical Supply Co., Park Place, New York City.
Fig. 113. the cathedral chimes
A. A full sized binding post.
B. The chimes on the sounding board.
Make eight spirals of No. 14 spring brass, steel or, better, phosphor-bronze[114] wire; you can do this by cutting off eight pieces of the wire each of which is 20 inches long. Draw a spiral on a sheet of paper as [described] in Chapter V so that the inside turn of wire is about ³⁄₄ inch in diameter, the outside turn about 3¹⁄₂ inches in diameter and each turn of wire will be separated from the other by a space of ¹⁄₄ inch as shown at B.
[114] Get it of the U. T. Hungerford Brass and Copper Co., Hungerford Building, New York.
With your round nose pliers bend each length of wire like the pattern you drew on the paper. When you have made the spirals screw the inside end of each wire in the binding post and your cathedral chimes are done all except the tuning of them.
Let the first spiral of the upper left hand side give the fundamental tone and tune the others to it by cutting off the free ends of the wires until they are all tuned in unison. Make a couple of wood mallets and cover the ends with leather or rawhide.
How to Play the Cathedral Chimes.
—Strike the inside turn of wire up close to the end that is fastened to the binding post, and a tone will issue from the spiral that is long, deep and loud, for the wire with its free end forms a very perfect vibrating body.
The Æolian Harp.
—How to Make It.
—This harp is of very ancient origin and it gets its name from Æolus who, in classic mythology, was the father of the winds, and very appropriately is it named, too, for it is the wind that plays it.
Make a box of ¹⁄₂ inch thick wood, 2 inches deep, 5 inches wide and 3 feet long; use clear pine, or deal will do, for the sides of it but the ends should be of beech to hold the tuning pins and the hitch pins. Cut a sound hole 3 inches in diameter near both ends of the board which is to be used for the top; then glue the box together and screw up the ends with your wood clamps to hold it together tight while it is drying.
Fig. 114. the harp of aeolus
When it is thoroughly dry, drill a dozen ¹⁄₄ inch peg holes ³⁄₄ inch deep in one end, six in a row as shown at A in [Fig. 114]. Make a dozen pegs to fit the holes and these should have wings on them as shown at [B] like violin pegs. Each peg should be about 1¹⁄₂ inches long and each one should have a ¹⁄₃₂ inch hole drilled near the top of the shank for the end of the string to pass through. The hitch pins can be brass brads driven into the other end of the box and in a line with the holes, all of which is shown at [A].
Make two bridges of hard wood ¹⁄₈ inch thick; have each one 1 inch high and 5 inches wide and with 12 notches cut in one side. Now get a dozen catgut strings of different thicknesses and put them on the sounding board; to do this twist a loop on the end of each one; thread the other end through the hole in the peg and tighten it up a little.
When you have all of the strings in place set a bridge under each end and then tune the strings in unison, but don’t stretch the strings on very tight or the wind won’t make them vibrate. This done, cut out another ¹⁄₂ inch thick pine board and glue a block ¹⁄₂ inch square and 1¹⁄₂ inches long to each corner and set it on top of the harp. The purpose of this cover is to make the wind blow with as much force as possible over the strings.
How the Wind Plays It.
—To the end that old Æolus may play the harp to the best of his ability set it on the sill of an open window so that the wind strikes the strings at a slant. Pull the window down on the harp in order to make all of the wind pass between the cover and the strings.
When the wind blows softly beautiful tones will be emitted and when the wind blows hard discords will be produced but as the wind subsides exquisite harmonies will again prevail.
An Egyptian Fiddle.
—How to Make It.
—The early Egyptians invented the fiddle, or rebab as they called it, but they did not play it with a bow. Later in medieval times, that is in about the 9th century, this fiddle came to be called a rebec and it was then played with a bow. I’ll bet though that the fiddle I shall tell you how to make and play sounds better than any Egyptian rebab ever made—though it is not exactly a Stradivarius.[115]
[115] The priceless fiddles made by the famous old violin maker Antonio Stradivari of Cremona, Italy, in the early part of the 17th century.
To make a fiddle of this kind—it only has one string and only one is needed by a master violinist—make a sounding box of ¹⁄₈ or ³⁄₁₆ inch thick wood except the ends which should be of ³⁄₈ inch thick stuff; this box should be 4 inches high, 6 inches wide at one end, 8 inches wide at the other end and 12 inches long. Cut a hole 6 inches in diameter in the center of the board which you are going to use for the sounding board, and then glue all of the pieces together using wood clamps to hold them tight.
For the neck take a stick of wood 1¹⁄₂ inches wide, 2¹⁄₂ inches thick and 15 inches long; cut it down until one end is 1 inch thick and cut a piece out of this end ³⁄₄ inch wide and 1 inch deep; bore a conical hole through this end and fit in a peg. Next saw out the other end 2 inches deep for a length of 3 inches back and glue and screw this end of the neck to the narrow end of the box. The shape of the neck with the peg in it and the way it is fixed to the sounding box is clearly shown in the top view A and the side view B in [Fig. 115].
Cut out a bridge of a piece of hard wood ¹⁄₈ inch thick, 1 inch high and 1¹⁄₂ inches long as shown at [C]; and, finally, make a tail-piece of a bit of hard wood ¹⁄₈ inch thick ¹⁄₂ an inch wide at one end, 1 inch wide at the other end and 2 inches long. Drill a hole in each end and whittle or plane the large end to a sharp edge.
In the middle of the large end of the sounding box bore a ¹⁄₄ inch hole and glue in a hard wood peg for a hitch-pin. Fasten the tail-piece to the hitch-pin with a piece of catgut string. Slip the end of an A violin string through the hole in the sharp end of the tail-piece; knot it to keep it from pulling through, and bring the other end up and thread it through the hole in the peg in the neck. Finally put the bridge under the string and tighten it up. Tune it to the treble, or G clef, if you know enough about music to do it, or if not tune it so that it gives a pleasing tone.
Fig. 115. plans for an egyptian fiddle
How to Make the Bow.
—The best kind of wood to make a violin bow of is Brazilian lance-wood or of snake-wood, but for this one stringed fiddle of yours you can use a piece of beech.
Take a strip of wood ¹⁄₂ an inch thick, 1 inch wide and 24 inches long and saw it out as shown at D; then round up the stick and sandpaper it smooth. Cut out two blocks to fit the ends, or frogs as they are called: drill a hole in each one and screw it to the bow but not very tight.
Fig. 115d. how the bow is made
Now comes the hard part and that is putting on the hairs; get 50 or 60 white horsehairs about 2 feet long; I do not advise pulling them out of Dobbin’s tail but rather to buy a bunch of them from Sears, Roebuck, and Co., Chicago, Ill., for 10 or 20 cents.
Having got them somehow put one end of each one under one of the blocks and when you have them all even and close together screw the block down tight; this done fasten the other ends of the hairs under the opposite block, and when you have them all drawn taut screw down the block and put a little glue on the places where they go under the blocks.
If you will look at a horsehair through a microscope you will see that it seems very like the scroll saw blade I told you about in the second chapter, that is, it has a lot of fine teeth on it and all of them run the same way. By rights then half of the hairs ought to be put on the bow with the teeth running in one direction and the other half with the teeth running in the other direction so that the friction of the hairs is the same on the string on the up and the down strokes.
Fig. 115e. how the fiddle is played
Do not use much rosin on the bow but rosin it often. You can buy a piece of regular violin bow rosin for 5 cents but the kind that gives the best results is the genuine Bernardel imported from France and which costs about a quarter. It bites hard on the string and makes a large volume of sound. The way the fiddle is played is shown at [E].
CHAPTER XII
SOME EVENING ENTERTAINMENTS
There is a feature of home life that the heads of too many families overlook and that is getting together and having an evening of entertainment which the youngest as well as the oldest member can enjoy.
This is not at all a hard thing to do but as it takes time to get the props together to give it with—which neither your father or mother can well spare even if they had the inclination—it is up to you as the boy of the family to see that it is done.
It is a noble plan to give a divertisement, or soirée[116] (pronounced swa´re) as the old time magicians used to call it, once every month and you will find after you have given the first one that all of your folks will look forward to the coming of the next one with interest and with pleasure.
[116] This is a French word and it means an evening social gathering.
Moreover, you should let them know what the next divertisement is to be a couple of weeks before it comes off and then let all hands join in and talk about it whenever the spirit moves them. Naturally since you know all about it and they don’t know anything about it, questions will be in order and you are the one who will have to answer them; and don’t try to make a secret of anything you have done or are going to do unless it is magic or some allied subject of mystery. After the divertisement is over it will furnish food for conversation for a long time to come.
Now while I have used the words entertainment and divertisement, both of which mean about the same thing and that is amusement, and while you should always strive to make your talks as light and recreational as you can you do not need to stick to frothy subjects altogether but instead you should alternate them with scientific demonstrations. In this way you will not only please and develop good fellowship in the family, but you will instruct the members of it at the same time.
Finally, don’t make your divertisements too long. Better by all means make each one only 15 or 20 minutes long and have everybody in high good humor and saying that it was all too short, than to give them an hour and have everybody gappy and bored half-to-death.
Cartoons While You Wait.
—This is a good feature to start off your season’s divertisements with. Make a substantial easel on which to set a large drawing board as shown in [Fig. 116], or you can fasten the paper to a wall with thumb tacks if you live in a home and not in a residence.
Get a dozen sheets of good white print paper—you can buy a quire (24 sheets) 24 × 36 inches for 25 cents—and tack ¹⁄₂ a dozen sheets to your drawing board or the wall. Also buy a stick of black marking crayon,[117] which is better than chalk or charcoal for it makes a heavy black line that will not smut, blur or rub off.
[117] You can buy a marking crayon at a hardware or stationery store.
Fig. 116. how an easel is made
Drawing the Cartoons.
—Start in with your crayon in hand and explain that what you propose to do is to show the principles upon which free-hand drawing is based. Then make a simple line drawing of the boxer reaching for the maxillary of his invisible opponent as shown in [Fig. 42], over in the chapter called Drawing Simply Explained, and then draw the horse galloping home on the three-quarter stretch.
Next draw around these simple line figures, which are really the skeletons of the man and beast, the outlines as shown in [Fig. 43]. If you are not expert in free hand drawing you can trace these figures on the paper in faint lines with a lead-pencil before you begin your performance, and then all you have to do is to mark over the lines with the crayon.
After you have made these drawings and explained all about them tear off the sheet and on the clean one draw the outline of a man as shown in [Fig. 44] and mark on the proportions of the human body. Have your next sheet ruled off into squares with the lines 2 inches apart; draw in the face and at the same time explain that this makes it easy for any one to get the features in proportion.
Now comes the grand finale[118] (pronounced fi-na´-le) and that is your cartoons.[119] You should practice drawing these and also have some patter[120] about each one so that when you do them for the family audience your tongue will be as clever as your fingers. You can begin by explaining how the expressions of one’s face—that is the way the features look when the mind is at rest or is excited—can all be represented by a few very simple lines.
[118] The last part of an exhibition and it is generally the climax of it.
[119] A cartoon is usually a caricature of a person or thing done in sketchy style. The word comes from the French carton, which means pasteboard.
[120] Witty or amusing talk to help along the act.
Draw eight circles 5 or 6 inches in diameter in a double row on the paper with your marking crayon as shown at [A in Fig. 117]. Now you say first that sleep can be represented by four straight horizontal lines and you draw them as shown in the first circle. Next draw four vertical lines in the second circle and before you can say awake your little audience will see it and laugh its approval.
 |  |  |  |
| FAST ASLEEP | WIDE AWAKE | SOME JOY | MORE SORROW |
 |  |  |  |
| QUITE MODEST | MUCH DISDAIN | SOMEWHAT SURPRISED | A LITTLE ANGRY |
| A |
Fig. 117a. first principles of cartooning
Joy is represented by four little arcs, or curved lines with the ends of each pointing up, which you draw in the third circle, while sorrow is, of course, shown by four curved lines the ends of which point down as in the fourth circle, since the emotion of sorrow is the opposite to that of joy.
Show how modesty is depicted by drawing four little angles in the fifth circle with the vertex, or point of each one at the bottom, while disdain, which is the reciprocal of modesty, can be illustrated in the sixth circle by reversing the positions of the angles and having their vertices at the top.
To portray surprise all you have to do is to draw four little circles inside the seventh large circle and you will have caught the expression. Finally in the eighth circle draw two slanting lines for the eyes, a vertical line for the nose and an angle with the ends of the lines pointed down and you will have a very good representation of anger, (or maybe it’s a Chinaman.)
| BY DE LIGHT OF DE SILVERY MOON | PAT AND HIS POIPE | HE HAS JUST HEARD A JOKE |
| B | C | D |
Fig. 117 b, c, d. three simple cartoons that you can do
Now without my telling you how to draw the cartoons shown at B C and D in [Fig. 117], draw each one of them half a dozen times on a sheet of paper with your marking crayon and when you get before your audience you will be able to do them like a lightning crayon artist.
Thirty Minutes of Chemistry.
—Here are some very pretty and easily made experiments in chemistry and as you perform them you can give the explanation I have written about each one which will serve as the patter.
The Mystic Glass of Milk.
—The Effect.—You show a glass of perfectly clean water and blow through it with a glass tube, clay pipe or a straw when it becomes to all intents, though not to all purposes, milk of the cow variety. See [Fig. 118].
| BEFORE BLOWING THROUGH STRAW | AFTER BLOWING THROUGH STRAW |
Fig. 118. the oracle of amor, or are you in love?
The Cause.
—To perform this chemical trick get 50 grams of good quicklime and powder it in a pint milk bottle. Let it stand for 24 hours and shake it every once in a while. Let it stand another 24 hours and then pour off the clear solution, which is called lime water[121] and this is the common name of mystic milk.
[121] You can buy it in a drug store all ready to use.
The Chemical Action.
—In the first place the lime in the water is calcium hydroxide and when you blow through the lime water the carbon dioxide in your breath acts on the calcium hydroxide and forms a white insoluble powder commonly known as limestone.
Since the calcium carbonate does not dissolve in the water it remains suspended in the solution and this gives it an opalescent hue that doth verily look like the lactic fluid which is white but woe unto the milkman who sells it as such.
For the Fun of the Thing.
—By pretending you can tell which boys and which girls are in love hand around several glasses of ordinary water and as many of clear lime water. You must see to it, of course, that those whom you want to make believe are in love are given the lime water; then have everybody blow and it is a sure sign that those who change the water into milk are in love.
The Magic Fountain.
—The Effect.—You show an empty bottle, or Florence flask, and then push a cork with two holes in it into the mouth of the bottle. Next push a glass tube having a nozzle on one end through one of the holes in the cork until the nozzle nearly touches the bottom of the bottle.
Through the other hole in the cork push a medicine dropper, or fountain pen filler. The end of the long tube projects down into a bowl containing water which you have colored blue[122] either with indigo or with copper sulphate or you can make a beautiful violet by dissolving in it a little potassium permanganate. The arrangement of the apparatus is shown at [A in Fig. 119].
[122] Any kind of colored water will do for this experiment.
Fig. 119a. the mystic fountain
Now when you squeeze the bulb of the medicine dropper the colored water rushes up the tube and squirts out of the nozzle into a pretty fountain until the flask is nearly full.
The Cause.
—Instead of the bottle being empty as it looks to be, you have previously filled it with hydrogen chloride gas of which 500 volumes will dissolve in 1 volume of water.
The medicine dropper is filled with water and when you squeezed it a few drops of water is forced into the bottle and dissolves a large part of the gas that is in it. This leaves a vacuum when, of course, the atmospheric pressure on the colored water in the bowl forces it up through the nozzle to fill the vacuum.
Fig. 119b. making hydrogen chloride gas
This water dissolves the rest of the gas in the flask and more water is forced up until the bottle is nearly full of it, all of which produces a very mysterious and at the same time a mighty pretty effect.
How to Make Hydrogen Chloride Gas.
—To make this gas take another bottle and fit a two hole stopper into it; in one hole put a funnel and in the other an L tube as shown at [B 119].
In the bottom of the bottle put ¹⁄₃ of a cup of common table salt; put a straight tube down into the Florence flask you want to fill and connect this tube and the L tube with a piece of rubber tube as is also shown at [B].
The apparatus set up, pour sulphuric acid down the funnel, a very little at a time until the salt is all gone and then fit the cork with the long nozzle tube and the medicine dropper in it, into the mouth of the bottle filled with the hydrogen chloride gas.
The Vicious Soap Bubbles.
—The Effect.—Show a dish of soap-suds and then blow bubbles with the apparatus described below.
When the bubbles take on a size of about 3 inches in diameter shake them off and they will rise slowly and gracefully in the air. Before they get out of reach touch them with a long lighted taper and they will explode viciously with a sharp report like that made by a revolver.
The Cause.
—The bubbles are filled with a mixture of hydrogen gas and oxygen gas and when these two gases are simply mixed they form a very explosive compound which is called detonating gas.
When the flame is brought close enough to the bubble it fires the gases in it, and they explode and combine chemically to form water. The apparatus necessary to do this experiment with is shown in [Fig. 120].
It consists of (1) a hydrogen gas generator and (2) an oxygen gas generator.
The hydrogen bottle or flask is fitted with a two hole stopper through which runs a glass funnel and an L tube just as described in the fountain experiment and shown at [B in Fig. 119]. Connected to the L tube is a length of rubber tubing into the other end of which another L tube is fitted.
The oxygen bottle or flask is fitted with a single hole stopper which has an L tube running through it as shown at [B in Fig. 119]. Connected to the L tube is fixed another length of rubber tubing and in the free end of this is fixed another and shorter L tube. Now place the two short L tubes side by side and cement them together with sealing wax. A long length of rubber tube is forced on over the ends of the double tube and, finally, a clay pipe is fitted into the free end of the rubber tube, all of which is shown in [Fig. 120].
Fig. 120. the vicious soap bubbles
Set the bottles or flasks as far apart as possible and in the hydrogen bottle put a handful of granulated zinc. Dilute hydrochloric acid[123] is poured down the funnel on the zinc when hydrogen will be set free, or generated as it is called.
[123] If you want to buy dilute hydrochloric acid ask for normal hydrochloric acid.
Put a small handful of a mixture of 2 parts of potassium chlorate and 1 part of manganese dioxide, finely powdered, in the oxygen bottle and then set a Bunsen burner under it when it will give off oxygen. When the two gases leave the short L tubes they mix in the long rubber tube and by the time they reach the clay pipe you will have detonating gas all right.
Caution.
—Do not bring a flame anywhere near the apparatus and as a further precaution wrap a thick towel around the hydrogen flask.
The bubbles that are blown rise in the air because both the hydrogen and the oxygen are lighter than the air.
The Uncanny Wheel.
—The Effect.—A pitcher is shown full of emptiness and then a cardboard wheel, 4 inches in diameter, with buckets, or cones 1 inch high and ³⁄₄ inch across glued to the rim and which is mounted on a wire so that it can be revolved, is passed for examination.
Placing the wheel on the table you hold the empty pitcher above it and pour out nothing on it when the wheel will turn round just as though you were pouring water on it. It is indeed uncanny. The idea is shown at [A in Fig. 121].
The Cause.
—But it is all canny enough when you know how it is done. While the pitcher is apparently empty you have, forsooth, previously filled it with a gas called carbon dioxide. This gas is 1¹⁄₂ times as heavy as air.
The cardboard wheel does not move in the air because the latter pushes on all parts of it equally. When, however, you pour the carbon dioxide gas on it from the pitcher, since it (the gas) is heavier than the air it fills the little buckets and makes them heavier just as surely as if you poured water on them; and hence the wheel revolves.
Fig. 121. the uncanny wheel
How to Make Carbon Dioxide Gas.
—Take a perfectly dry bottle or flask of the kind shown in the [fountain experiment]; fit it with a single hole stopper and push a glass tube through it until it nearly touches the bottom as pictured at [B].
Set the bottle at a slant and put a mixture in it of equal amounts of powdered copper oxide (that is cupric oxide) and wood charcoal. Heat this mixture over a Bunsen burner until it glows and for a few minutes longer; the bottle will then be full of the carbon dioxide gas.
Pour it into a glass pitcher and put a sheet of glass over it to keep the air away from it until you are ready to perform the uncanny experiment.
Giving a Travelogue.
—A travelogue is simply a talk on travel, or on a country, illustrated with pictures of some kind.
To be able to give a travel talk does not mean necessarily that you must have traveled or been in the country you are going to tell about but if you have done neither, it does mean that you must read up on it.
To do this get several good books on whatever country you intend to talk on, read them carefully, and then outline a route just as though you had gone over it yourself, but this must of course conform to the pictures you can get.
Now there are four methods you can follow to show a series of pictures and you can make your choice according to the amount of money you want to invest in it.
(1) The first and least expensive way is to cut a dozen or twenty pictures out of magazines, arrange them according to your route and build up your talk around them. As you describe each place pass the pictures, which should be mounted on cardboard, in turn to each person present.
(2) A better way is to get a set of stereographs of the trip or the country you are to talk on and a stereoscope[124] and pass the picture showing the view and the instrument to each person present.
[124] A stereoscope and the stereograms can be bought from Underwood and Underwood, 417 Fifth Ave., New York, or Sears, Roebuck and Co., Chicago, Ill.
Each stereograph, as the picture is called, is formed of two pictures of the same scene made from slightly different viewpoints and when the observer looks through the lenses at them they blend into one image when the scene stands out wonderfully clear and apparently in three dimensions. The only drawback of the stereoscope as an aid to a travel talk is that only one person can look at a picture at a time.
(3) A far better plan than either of the above schemes is to make a reflectoscope[125] as [described] in the chapter called Some Kinks in Photography. You can show any kind of a picture in a reflectoscope if it is not larger than 3×5 inches but picture postcards are especially good to use for a travelogue or a talk of any kind and they show up nicely when thrown on a screen with a reflectoscope.
[125] You can buy one of the Bausch and Lomb Optical Company, Rochester, New York, and you can get post-card views for it of the Post-Card Store, 946 Broadway, New York.
(4) Finally either make, or better, if you can afford it, buy, a magic lantern[126] that will take the regular full size lantern slides, namely, 3¹⁄₄ × 4¹⁄₄ inches square. Sets of lantern slides[127] for travelogues or talks on any subject can be rented cheaply and in these days of cheap electricity you can throw a picture on the screen so big and bright and real that your offering is bound to be a success.
[126] For magic lanterns and slides address the Charles Beseler Co., 131 East 23rd Street, New York.
[127] Sets of lantern slides can be rented of the Charles Beseler Co., 131 East 23rd Street, New York City.
An Electrical Soirée.
—Experiments in electricity are always interesting to all however young or old, for of all the powers that have been harnessed by man it is the least tangible and yet the effects produced by it are the most spectacular.
Now there are some very extraordinary effects that you can show with static electricity[128] which do not require apparatus of any kind as you will presently see, but if you will make or buy a ¹⁄₂ inch induction coil[129] you can perform a series of classic experiments that will create a profound and lasting impression on all who see them.
[128] Many experiments with static electricity will be found in The Book of Electricity by the present author and published by D. Appleton and Co.
[129] Complete instructions for making an induction coil will also be found in The Book of Electricity.
Demonstrating Electricity Without Apparatus.
—Did you ever rub a cat in a dark room in the winter and see the sparks fly? Well this is one way to make electricity without apparatus though you need a cat[130] to do it with.
[130] A cat is not apparatus but only a kitten growed up.
The Electrified Papers.
—But you can make a lot of electricity by simply rubbing a newspaper if you know how to rub it and it is perfectly dry.[131]
[131] Winter is the best time to do experiments in static electricity.
A—ELECTRIFYING A STRIP OF NEWSPAPER
B—ELECTRIC ATTRACTION
Fig. 122. the electrified paper
Tear off a strip of newspaper, lay it flat on a table and rub it with your finger nails as shown at [A in Fig. 122]. When you try to take the paper from the table you will find that it sticks to it quite tenaciously. This is because you have positively electrified the paper when you rubbed it and the surface of the table under it is negatively electrified by induction.[132] Now since positive and negative electricity attract each other, the paper and the table are pulled together.
[132] The theory of induction is simply explained in The Book of Electricity by the present author.
How to Electrify a Person.[133]
—This is an experiment that will make your gathering giggle just as school girls giggle when they have their tintypes taken—that is without any real reason except that the idea strikes their mental funny bones.
[133] Since the paper is positively electrified the person must be negatively electrified.
To perform this experiment electrify a strip of newspaper as above and then hold it close to some one’s face; instantly there will be a mutual attraction between them and the paper will be drawn to and stick to his or her cheek. Put an electrified paper on the cheek of each person present as shown at [B] and tell them they belong to the same club. This will get a laugh but it will not lessen their interest in the experiment in the least.
How Like Repels Like.
—Electrify two strips of newspaper this time and hold them together by the ends. Instantly the free ends of the papers will fly apart for like signs of electricity repel each other.
That is, since both strips of paper are positively electrified and hence are of like signs, they repel each other. If they were negatively electrified they would repel each other just the same. In either case it shows that there is a force acting across the space between the two strips of paper.
Making Experiments With Apparatus.
—With a dry battery of two or three cells, an electric bell, a common steel magnet and an electromagnet, all of which you can easily make or buy[134] for a dollar or so, you can provide entertainment enough for ¹⁄₂ an hour’s demonstration, and food for thought to last a year.
[134] The L. E. Knott Apparatus Co., Boston, Mass., and The Manhattan Electric Co., Park Row, New York, sell all these things.
The Induction, or Spark Coil.
—An induction coil is an apparatus for changing a direct low pressure, but large quantity current from a battery into an alternating high pressure but small quantity current, which is called high tension, or high potential, electricity.
With an induction coil you can make any number of wonderful experiments such as miniature streaks of lightning, lighting up Geissler tubes, which produce brilliant and beautiful colors showing the electric discharge in gases, etc., etc. By fixing these tubes to a small electric motor[135] so that they can be revolved while the high tension current is passing through them, the effects are further heightened.
[135] A small electric motor can be bought for $1.00 of any dealer in electrical supplies or of the Manhattan Electrical Supply Co., Park Row, New York.
Demonstrating Wireless Telegraphy.
—All you have to do to make your induction coil into a wireless transmitter, that is, the sending apparatus, is to put a couple of brass balls on the points of the spark-gap, fasten a wire to one of them and the other end to a nail in the wall near the ceiling and then connect the other one with a wire which ends in a small sheet of brass or copper that rests on the floor as shown at [A in Fig. 123].
To make a receiver that will tap out the signals you send on your transmitter, you will need (a) a coherer, (b) a relay, (c) an electric bell and (d) a dry cell. You can make the coherer but the other three pieces of the apparatus you had better buy.
Fig. 123. a simple wireless demonstration set
For the coherer cut off a piece of brass rod ¹⁄₈ inch in diameter and 1¹⁄₄ inches long, file the ends off even and slip them through the holes in the binding post. Put a pinch of nickel and silver filings into a piece of glass tubing about an inch long and push the ends of the rod into the tube with the filings between them.
Screw the rods into a couple of binding posts set 2 inches apart on a block as shown at [B] and your coherer is done.
Connect up the coherer, relay, tapper and dry cell on a board as shown in the wiring diagram at [C]; fasten a wire to one of the rods of the coherer and to a nail near the ceiling; fix a wire to the other coherer rod and to a small sheet of brass or copper which rests on the floor.
Fig. 123b. cross section of the coherer showing its construction
Now when you press the key or button of the sender, which is on one side of the room, the bell of the receiver, which is on the opposite side of the room, will ring out a signal. The fact that there are no wires connecting the sender with the receiver will create much wonder.
The theory of wireless telegraphy is rather deep but you will find it simply explained in my Book of Wireless published by D. Appleton and Co., New York City.
Reading Palms for Fun.
—Many years ago when P. T. Barnum was exhibiting a sacred white elephant, which was nothing more nor less than a small Indian elephant covered with whitewash, and the good folks were breaking their necks to pay their hard-earned coin to see it, the great showman remarked that “the American people love to be humbugged.” And they do. Now palmistry is a kind of mild humbuggery on a small scale and for an evening of fun and bunkum-squint you can’t find anything to beat it.
Fig. 124a. the parts of the hand named according to science
First of all there are three words that are constantly used in the art which you must know how to pronounce correctly or you will surely show your ignorance. The first is palm, pronounced pom; the second is palmist, pronounced pol´-mist, and the third is palmistry, which is pronounced pol´-mis-try; now be sure to say them right.
Fig. 124b. the parts of the hand named according to palmistry
While nearly every one believes in palmistry there is nothing in it in-so-far as it is possible to read a person’s character or to divine one’s future by means of it; but there are some things you can tell from the hand you are reading and these are if its owner is or is not in good health and whether the brain that goes with it is mechanically inclined or is of an artistic temperament.
Further you can gather—not from the hand but from the face, stature, carriage, and mannerisms of the boy or girl or the man or woman whose hand you are supposed to be reading—a good deal about his or her temper and temperament and also about her or his foibles and peculiarities. In fact the palmistry of the palmists is simply a study in deduction, very much a la Sherlock Holmes, of the person as a whole, and it is by no means limited to an investigation of the hand alone.
How to Read Palms.
—There are two things which you should learn before you begin to read palms and these are (1) the names of the different parts of the hand, and (2) the lines and mounts of the hand.
The names given and the corresponding parts of the human hand are shown at [A in Fig. 124]; these are the scientific names and you will add very greatly to your stock of knowledge to get them down by heart.
The names, of the lines and the mounts of the hand are given and shown at [B] and these are the terms that are used by palmists. You will observe that the eminences are called mounts and these are named after the planets of the solar system, for the ancients supposed that they were inter-related. To get by as a palmist it goes without saying that you must have these all down pat.
To find out what kind of health the subject is in, grip the hypothenar eminence, which is the side of the hand opposite the pollux, or thumb, between your thumb and fingers and squeeze it a little; if it is perfectly firm and the palm has a good healthy color you are quite sure that its owner is in good health, but if the flesh is soft and is not elastic and if the palm is pale and bloodless you will be quite right in saying that the subject’s health is not good, nay worse, it is even bad, and you will not offend your subject by so saying.
The length of the life line is supposed to determine how long the subject who owns it will live but even if you find one broken off short never tell the person that he or she will live only a short time. Indeed to be a successful palmist tell every one whose hand you read that she or he will live to be anywhere from 80 to 108, and you’ll be on the safe side.
The line of the heart, according to palmistry, indicates the affections and passions of a person. Always tell a fellow that he is a great lover and that he is constant, but you can say to a girl that she is capricious, which means about the same thing as being fickle, and both the man and the maid will be highly pleased. The line of Saturn is the line of disposition and you must always make the subject just as sweet and angelic as possible unless you want her to break up the séance[136] then and there and hold a wake to prove you’re right.
[136] A sitting given by a medium or a palmist is called a séance (pronounced say´ance).
Apollo, as the line of fortune is called, is a good one to talk at length on; you can tell every subject that he or she has had bad luck, but that fortune will follow; that he or she will marry a pretty girl, or a handsome man as the case may be, live in New York if already living in the country and the other way about—for everybody wants to live anywhere except the place he is in—and don’t forget to say “you’ll live happily ever after.”
Since folks will foolishly believe in palmistry don’t try to convince them to the contrary, but while there is nothing in it, when you play palmist tell them only the nice, pleasant things and you will then be doing them a real service.
Just two more pointers on the ignoble art of palmistry and these are (1) read the palms of each one present right out loud before the whole gathering, and (2) be mighty careful that the single girls and married ladies do not switch rings and so lead you into the trap of thinking that the former are enjoying a state of connubial felicity (whatever state[137] that may be) and that the latter are living in a territory[138] of single blessedness.
[137] Probably Utah.
[138] Most likely Arizona.
A Talk on the Steam Engine.
—For your final evening entertainment give a thumb-nail lecture on steam and the steam-engine.
You will find every one is interested in steam because it is one of the great prime movers but there are very few people indeed who have any idea of how a steam engine works.
If you will do exactly as I tell you, you can talk on and demonstrate the principles of a steam engine so that, whatever the age of your listeners, they will know, when you are through, exactly how and why a steam engine runs and develops power.
Making the Model Engine.
—The engine I shall tell you how to build is not a model that runs by steam,[139] but one made almost entirely of wood and the purpose of it is not actually to produce power but to show exactly how it works.
[139] How to build model steam engines and all other kinds is explained in my new book Engine Building for Boys, published by Small, Maynard and Co., Boston, Mass.
To the end that this may be done the cylinder and steam chest are split-down the middle lengthwise so that the inside of them can be clearly seen and the movements and functions of the piston and the slide valve in these parts will be clear.
Make the cylinder first and the easiest way to do it is to saw out two disks of wood for the cylinder heads of ³⁄₄ inch thick stuff, 4¹⁄₂ inches in diameter and bore a ⁹⁄₁₆ inch hole through the center of one of them for the piston to slide through, as shown at [A], [C] and [F] in Fig. 125. Turn, or whittle out a piece of wood for the stuffing box,[140] 1 inch in diameter and ¹⁄₂ inch long, and bore a ⁹⁄₁₆ inch hole through the center of it and glue it to the center of the cylinder head so that the holes are exactly in a line as shown at [A] and [F].
[140] A stuffing box on a real steam engine is to keep the steam in the cylinder and steam chest from leaking past the piston rod and the slide valve rod.
Fig. 125a. working drawings for the demonstration steam engine. cross section side view of the engine
Next saw out two rings of ¹⁄₄ inch thick wood, make the outside 4¹⁄₂ inches in diameter and the inside 3 inches in diameter, see [C], and glue one of the rings to each end of the cylinder heads. Now cut out of a sheet of thin cardboard, or better of tin, a piece 5³⁄₄ inches wide and 6 inches long; cut two holes ¹⁄₂ an inch in diameter and have the center of each hole ¹⁄₂ an inch from one of the long edges and ⁷⁄₈ inch from each of the short edges as shown at [D].
The next thing on the list is the piston and the piston rod. For the piston, saw out a disk of wood 3 inches in diameter and bore a ¹⁄₂ inch hole through it in the center. The piston rod is simply a piece of wood ¹⁄₂ an inch in diameter and 12 inches long; cut a slot in one end ¹⁄₈ inch wide and ¹⁄₂ an inch deep and bore a ¹⁄₁₆ inch hole through it as shown at [C]. Put the piston inside of the cylinder, slip the piston rod through the hole in the cylinder head, smear some glue on the end of it and fit it into the hole in the piston.
The steam chest is next in order; for it use ³⁄₁₆ inch thick wood and saw out four pieces 2 inches square; two of these pieces are for the heads of the steam chest, as shown at [A] and [B], and in the center of one of them drill a ³⁄₈ inch hole for the slide valve rod to go through. Turn, or whittle out, a piece of wood for the stuffing box ¹⁄₂ an inch in diameter and ¹⁄₂ inch long, bore a ³⁄₈ inch hole through the center of it and glue it to the center of the steam chest head that has the hole in it as shown at [A], [C] and [F].
Saw two holes 1¹⁄₂ inches square out of the other two 2 inch square blocks and glue these to the steam chest heads. Now make a trough of ¹⁄₄ inch thick wood, or of cardboard or tin, 1¹⁄₂ inches square, outside measurement, and 2³⁄₄ inches long; this is for the sides of the steam chest; as shown at [A] and [F].
Fig. 125b. end view of the engine. d. the crank shaft. e. the rocker arm
Bore a ¹⁄₂ inch hole in the center of the top of the trough; this hole is for the intake port, that is the opening through which the steam flows from the boiler into the steam chest. Bore three ¹⁄₂ inch holes in a line in the middle of the bottom of the trough as is also shown at [A] and [F]. The two holes nearest the ends are the ports to let the steam into and out of the opposite ends of the cylinder, and the central hole, or port, is the exhaust port [C].
Fig. 125c. top view of the engine
Next make the slide-valve; use ¹⁄₈ inch thick wood and make it ³⁄₄ inch high, 1 inch wide, and 1¹⁄₂ inch long on top and 2 inches long on the bottom; the bottom, as you will observe at [A] and [E], is cut out so that it will cover one of the cylinder ports and the exhaust port at the same time and you need put only one side on it.
The slide valve rod is a piece of wood ¹⁄₄ inch in diameter and 11¹⁄₂ inches long. Whittle or plane one end flat and drill a ¹⁄₈ inch hole through it. This done, set the slide valve in the steam chest; slip the slide valve rod through the head and glue it to the slide valve.
Now make four tubes or pipes of cardboard or tin ¹⁄₂ an inch in diameter, and have two of them 1¹⁄₄ inches long and the other two 3 inches long; when you have formed all of them cut a strip ¹⁄₂ inch wide out of each one lengthwise; the purpose of which is to show that they are hollow.
When you have the tubes done glue, or otherwise fix, one of the short ones into the intake port of the steam chest and the other short one into the middle, or exhaust port in the bottom of the steam chest; then glue, or fix the two long tubes into the end holes, or ports, of the steam chest and the holes in the cylinders.
Saw out a guide block for the piston rod to slide through, 2 inches wide, 3 inches high, 3 inches long on top and 5 inches long on the bottom as shown at [A] and [C], and bore a ³⁄₈ inch hole through the middle of the top of it lengthwise so that the center of the hole will be exactly 2¹⁄₄ inches from the base line.
Likewise saw out a guide block for the slide valve rod and make it 1 inch wide, 2 inches long and 3¹⁄₄ inches high and drill a ³⁄₈ inch hole through the middle of the top of it lengthwise so that the center of the hole will be exactly 2¹⁄₄ inches from the back board to which it is fixed.
Next cut out a rocker arm of a ¹⁄₄ inch thick piece of wood and have it ³⁄₈ inch wide at one end, ³⁄₄ inch wide at the other end and 7 inches long; drill a ¹⁄₈ inch hole in each end and a 1¹⁄₈ hole 1¹⁄₂ inches from the large end; pivot the small end to the end of the slide valve rod with a machine screw having a nut on the end of it.
Cut out an eccentric rod ¹⁄₄ inch thick, ³⁄₈ inch wide and 8¹⁄₂ inches long, and drill a ¹⁄₈ inch hole at each end so that their centers will be exactly 8 inches apart: pivot one end of this rod to the second hole in the rocker arm with a machine screw as before. Saw out a pivot block 1 inch square and drill a ¹⁄₈ inch hole through the center of it and pivot the lower end of the rocker arm to it with a screw.
Make a connecting rod, to couple the piston rod to the crankshaft with, ³⁄₈ inch thick, ¹⁄₂ an inch wide at one end, ³⁄₄ inch wide at the other end and 9 inches long; whittle or plane down the small end so that it will fit easily into the slot in the end of the piston rod and drill a ¹⁄₈ inch hole in each end so that their centers are precisely 8¹⁄₂ inches apart.
The crankshaft can be made of a piece of ¹⁄₈ inch thick wire 13 inches long which must be bent to the exact shape shown at [D]; before it is thus bent, however, slip the wire through the hole in the end of the eccentric rod and then bend the crank on it.
Saw out a flywheel of ¹⁄₂ inch thick wood, 8 inches in diameter, drill a ¹⁄₈ inch hole through its center and force it on over the wire forming the crankshaft; then slip the end of the connecting rod on the other end of the crankshaft wire and bend it to form a crank.
The front end of the crankshaft must be supported by a pillow block just as it is in a real engine, but the rear end is held in place by a board screwed to the back of the base. This block is ¹⁄₂ an inch thick, 1 inch wide at the top, 2 inches wide at the bottom and 3 inches high; drill a ¹⁄₈ inch hole in the top of it exactly 2¹⁄₄ inches from the base line and slip this over the end of the crankshaft next to the connecting rod.
The last thing to be done is to make a base to mount the parts of the engine on; this is a sort of a shelf and it is built up of a board ³⁄₄ inch thick, 6 inches wide and 31 inches long for the base. Saw a slot in it ³⁄₄ inch wide and 9 inches long in one corner, 2 inches from one end and ¹⁄₂ an inch from the side; this is for the fly-wheel to set in.
Fig. 125f. the steam engine ready to demonstrate
Screw a back to it ¹⁄₂ an inch thick, 10 inches wide and 3 inches long; this must be perfectly rigid and if necessary you can brace it with angle blocks. Finally glue four legs 1 inch square and 2¹⁄₂ inches long on the corners of the base-board.
To put the engine together, or assemble it as it is called, screw the cylinder to the base-board, then glue or screw the piston rod guide block to the base; the slide valve rod guide block to the back board, and the pivot block for the rocker arm to the base-board.
Drill a ¹⁄₈ inch hole in the back board 2¹⁄₄ inches up from the base-board exactly 16¹⁄₂ inches from the front cylinder head; put one end of the crankshaft in the hole and slip the other end of it into the pillow block; see that all is in a line and that the flywheel clears the sides of the slot in the base-board. Then it is all done and will look like [F].
How the Engine Works.
—Now if you will turn the flywheel around with your hand, or better, belt a small electric motor to it, you will see exactly how the slide valve opens first one port in the cylinder and then the other and that when the port is open which gives a clear path for the steam to flow from the steam chest to the cylinder, the other port is connected to the exhaust pipe, when the used steam passes into the open air.
When you know all about it you are then ready to give your last evening divertisement and for the time being to say Good-by.
THE END