The art of decorating dry goods windows and interiors

Electric power, as applied to the show window, may be divided into two sections: (a) Electric lighting, and (b) electric mechanism. We will consider these sections separately.

LIGHTING THE WINDOW.

The most approved method of stationary electric lights for windows are those placed at the top, next to the window pane, and so arranged as to throw their light downward and backward from the observer. Thus the entire window space is fully illuminated and the incandescents are themselves hidden from view. Separate reflectors or a long reflecting trough of tin should be placed back of the lights. Special lighting effects are explained in detail further on, but the regular lighting is best arranged as above.

COLORING ELECTRIC LAMPS.

Where colored effects are desired the incandescent lamp globes may be tinted to throw distinct or combined colorings over the entire display.

There are several preparations that answer the purpose, and indeed are best at times. Pikron for glass is excellent, or a lacquer will answer. However, they sometimes become spotted from the heat.

Another and better method is by using white shellac, thinned down with wood alcohol, and by dipping the globe this produces a splendid imitation of ground glass when a white light is needed.

If you wish to use purple, green, blue, etc., or any of the more delicate tints, such as violet, buy five cents’ worth of aniline dye of the color you wish; dissolve it in wood alcohol and pour it into the shellac, taking care the shellac is quite thin, as otherwise it will not cover evenly.

By using these or any other transparent coloring a vast number of beautiful tints can be made that will blend perfectly with your color scheme. Another excellent coloring is egg dye, treated in the same way.

Now I will explain how to go about it. After preparing your shellac pour it into a vessel deep enough to immerse your lamp.

Take a piece of wire, and fasten it around the socket end of lamp; then bring one end of the wire back over the end, and fasten to opposite side to form a loop to hang it up to drip and dry.

This done, dip lamp in the coloring and hang it up, so it will dry evenly, when it will be found to be beautifully frosted.

When mixing your color, bear in mind the more dye and the less shellac the deeper your tint will be, and vice versa.

This method will apply to all colors except a deep red or deep yellow, when I recommend the other colorings I have mentioned, any of which can be removed with wood alcohol.

GENERAL ELECTRICAL INSTRUCTIONS.

Before proceeding with explanations of designs requiring special wiring, it is well for the amateur to become acquainted with the primary principles of electricity, without which he is helpless. The following notes we culled from writings of experienced electricians.

POTENTIAL OR ELECTRO-MOTIVE FORCE.

This (commonly E. M. F.) is the term used for electrical energy or power of doing work, and is used in the same manner as “pressure” is applied to steam; in other words, it is the term used to express the force which tends to move electricity from one place to another, and is proportional to the difference of potential at the two places.

The earth’s surface is called “Zero Potential,” and is a reference point to measure the relative condition of other bodies. A positively electrified body is said to have a higher potential than the earth, which in turn has a higher potential than a negatively electrified body.

When two dissimilar metals touch each other, there is a difference of potential at point of contact. If zinc is in contact with copper it is of higher potential. In a series of disks of copper, zinc and wet cloths, arranged one over the other in above order, the wet cloth is the conductor, and current will flow on joining last copper and zinc by wire, etc.

This arrangement is called a voltaic pile (after its inventor, Volta), and the difference of potential produced is proportionate to the number of pairs of disks.

A difference of potential between two points connected will cause current to flow till the potentials of both points are the same.

ELECTRIC RESISTANCE.

Resistance is offered by all substances to the electric current, and varies with the nature of the substance.

Most metals are good conductors; wood and stone offer considerable resistance, and silk, glass and ebonite are practical non-conductors; but remember if a non-conductor is wet or even damp it becomes a good conductor, moisture or water being a first-class conductor. On the other hand, conductivity is diminished by an increase of temperature—otherwise dryness. The following table will give a good idea of the conductivity of metals:

Therefore, generally, good conductors are all the metals, carbon, water, aqueous solutions, moist bodies besides wood, cotton, hemp, etc. Good insulators or non-conductors are paraffine, solid or liquid, turpentine, silk, sealing wax, india rubber, dry glass or porcelain. The best electrical conductors are the best thermal conductors, and a “red hot” temperature converts insulators into fairly good conductors.

ELECTRICAL MEASURES.

Electricity being invisible and imponderable (i. e., not having sensible weight, such as light, heat or electricity), it is impossible to apply ordinary standards of measure. Electricians have devised special units of measure of two kinds, called absolute units and practical units, the ratio between the two being always some power of 10.

It has been decided in these measurements, length, mass and time shall be expressed respectively in centimeters, grams and seconds—called C. G. S., or centimeter gram-second method.

A gram equals 15.432 grains, a centimeter 0.3937 of an inch. The weight of a body must not be confused with its mass; the mass is the amount of matter contained, while the weight is its specific gravity, which may be expressed by multiplying mass by accelerating effect of gravity, which varies at different parts of the earth’s surface, and may be averaged at 32.2 feet (or 981 centimeters) per second.

The above absolute units are too large or too small for practical use, but the following examples are given:

The dyne (absolute unit of force) is that force which, acting for one second on a mass of one gram, imparts a velocity of one centimeter per second.

The weight of one gram, as above shown, is equal to a force of 1 × 981 = 981 dynes.

The erg, or absolute unit of work is the work requisite to move a body of one centimeter against a force of one dyne.

The weight of one gram is equal to 981 dynes, the work of raising one gram one centimeter, against the force of 981 ergs.

An erg is about equal to 1/13,560,000 of a foot-pound. A foot-pound represents the work required to raise one pound one foot high.

The practical units of most frequent occurrence are: The volt, the ohm and the ampere.

The volt, or measure of E. M. F., or difference of potential, is equal approximately to the E. M. F. possessed by one “Daniell” cell; accurately it is 0.95 of the E. M. F. of a cell.

The ohm, or measure of resistance (sometimes called the British Association or B. A. unit), is approximately equal to the resistance of 129 yards of copper wire ¹⁄₁₆ inch in diameter, or to 106 centimeters of mercury, one square millimeter in section.

The ampere (formerly called the “Weber”) is the measure of strength of current. If an E. M. F. of one volt be applied to send a current through a resistance of one ohm, the strength of current will be one ampere. That is to say, the strength of a current in amperes varies directly as the E. M. F. applied to produce it, and inversely as the resistance of the circuit.

The watt or practical unit of work (or rather, the rate of doing work) is equal to 10,000,000 ergs per second, or to the work produced in one second by one ampere of current of an E. M. F. of one volt, acting through the resistance of one ohm.

The practical electrical units are called after the eminent scientific investigators whose names they bear.

BATTERIES.

The portion of the copper plate (or carbon) from which the current flows through the wire is called the positive pole (sometimes anode), and the zinc plate the negative pole (sometimes cathode).

Elements, or the parts that produce current, are usually understood as the lower portion of the cell contents, in which the plates are immersed. When the term “pole” is reversed, the zinc being the positive element, and the copper or carbon the negative element, it will be noted current flows from positive pole (copper or carbon) and returns by the negative (or zinc) pole.

The bubbles of hydrogen gas liberated at the negative element (copper or carbon) resist the passage of the current, and being readily oxidizable, will set up an opposing E. M. F.

A battery in this condition is polarized—that is, neutralized—and must be renewed.

The E. M. F. of a cell is equivalent to the difference of potential between its electrode when unconnected, and is independent of the size of the elements, and is determined solely by the materials of which it is constructed.

The difference of potential between zinc and carbon being greater than that between zinc and copper, a cell of greater E. M. F. will result from zinc and carbon.

The cells commonly used for annunciators, bells, etc., are the “Laclede” and “Laclanche,” and are generally taken to have an E. M. F. of one and one-half volts; the “Danniell,” one volt; others vary from one to two volts when in good order.

To renew these cells fill the jar two-thirds full of clean water, add six ounces sal ammoniac, let it dissolve; then put in the zinc and carbon; be sure they are perfectly clean; and that the zinc is not worn out or eaten away. There are two ways to connect up these cells; the first is “in series” for E. M. F., the second “in parallel” for quantity. The first method “in series” is as shown. This way the E. M. F. is in proportion to the number of cells, three cells having three times the E. M. F. of one volt.

The second method, “in parallel” for quantity, is as shown; all the negatives (zinc) are connected, and all the positives (carbon) connected, making the current obtained of much greater volume, but only of the E. M. F. or intensity of one cell.

The strength of a current given by a battery varies with the resistance, as well as with the E. M. F., and can be increased not only by adding more cells “in series,” but also by lessening the internal resistance, viz., by increasing the size of battery plates, or more simply by coupling all the + (positive) poles together, and all the - (negative) poles together. The E. M. F. of cells coupled in this way is only equal to that of a single cell, but the current will be greater because the internal resistance will be only one-third that of a single cell. This plan is called coupling up for quantity, or “in parallel,” to distinguish it from the plan of “in series,” or for intensity.

The E. M. F. of a large and small cell are both the same (using same size elements). To increase E. M. F. multiply the cells “in series.”

The ordinary battery carbon is a mixture of carbon and peroxide of manganese—“Oh, Mr. Window Trimmer, please see if you can make this bell ring.” Bell No. 7 is dead, and there is no end of trouble; this is something met with occasionally. Examine the battery, see that it has not become crystallized (polarized), and if so, disconnect one cell at a time. Clean it well, without wetting the outside of jar, recharge with new zinc (if required) and six ounces powdered sal ammoniac, jar being first filled two-thirds full of warm water, or enough to avoid overflow; replace cell, connect up and take out another. Be sure to reconnect the cells left in battery, so as to keep it working while you are cleaning each one. A good way, if you don’t think the cells need changing, is to take a small call bell or buzzer, with short wires, disconnect both ends of battery, then test every cell by placing a wire on each pole of the cell at same time. If cell is all right, bell will ring. Suppose you find cells all right, proceed to bell No. 7, the dead one, examine the push button, and trace the wires from bell to battery, being sure they are not grounded by lying on some steam or gas pipe with the insulation worn off. (If it should be a case of continual ringing, the wires are crossed.) You may expect a “ground” if the battery has run down suddenly or too quick. If the trouble is found in the annunciator, don’t bother with it, unless you are expert or want trouble. Send for an electrician; it will save time—in other words, money.

SPECIAL WINDOW WIRING.

Many houses have ample facilities for electrical work, but as they do not employ a house electrician many beautiful and attractive effects are barred in their windows. Even when an attempt is made to introduce electrical effects into displays the results are tame and insignificant, because of a lack of special wiring. Yet we know that the success of many windows depends largely upon their illumination.

In some mercantile establishments the trimmer has an electrician at his beck and call, and when a design is ready he simply pushes the button and Mr. Electrician does the rest. But I know that these are exceptional cases, and that in the majority of establishments the trimmer is thrown upon his own resources, and has no one to help him out of his difficulties. And if he is not posted on electrical appliances, his designs are not properly illuminated—a deficiency that annoys the conscientious trimmer as much as it does his employer.

Electricity, properly applied, is an important factor in selling goods through the show window. Therefore the window trimmer who understands wiring his own windows is a more valuable man to his employer than one without this knowledge. I shall endeavor to be plain and avoid the use of unnecessary technical terms.

No doubt your windows have permanent lights. The first thing to do is to have a switch or “cut-out” run in for special work. Any electrician will do this for you in an hour or so, and it saves you from tapping your permanent wires, which should never be done.

Be sure to ascertain the voltage and amperes; or, to be plainer, find out how many lights your “cut-out” will carry.

Before you begin work you must have proper tools to work with, and sufficient supplies to meet any case of emergency.

ELECTRICAL TOOLS.

The following is a list of tools required:

That is not a formidable list, nor difficult to procure; but each item is necessary.

STANDARD ELECTRICAL SUPPLIES.

The list of supplies you should keep on hand is as follows:

This last item you can get prepared with resin, and it needs no acid to make it adhere.

No quantities are specified in the list. Your judgment will enable you to determine how much you will need or can use to advantage.

ARCS AND INCANDESCENTS.

Perhaps I would better explain here the difference between arc and incandescent wiring. If we had a row of arc lights to put up we could run our wires as in Fig. 1. The current going to the first light passes through to the next, and so on until it reaches the last light, when it returns to the dynamo.

With incandescents we run two wires parallel, and make our connections as in Fig. 2. This is called “multiple arc.” Each lamp is independent of the others, and if one “dies” the current passes through the others uninterrupted.

Suppose you have a “cut-out” of 110 volts, carrying sixteen or twenty lamps, and wish to run six lamps on a strip. (This is figurative, and only used to demonstrate, for you can use any number up to the capacity of your switch.) You proceed as follows: Lay out the place for each lamp. Bore two holes the size of bushings, and between each two lamps place two knobs, as in Fig. 3. Cut two pieces of wire, long enough for all the lights, allowing enough extra to knot each knob and for the last lamp, and also leaving enough to reach the switch. Fasten the wire to the knobs nearest the last lamp, as in Fig. 4. Stretch tightly to the next knob, and repeat until the wire is all laid. For each lamp remove about one and one-half inches of insulation on each wire. Take pieces of wire five inches long for connections, and remove one and one-half inches of insulation from the ends of each. Twist these ends tightly around your lead wires, as in Fig. 5, and solder them. The simplest way to solder is to heat your exposed wires until they are hot enough to melt the solder when it is held against them.

Let me say here that when I have laid out my wires, and marked my connections, I then unloose the wires, make my cross-connections and replace them. It takes time, but it is easier, and is the proper way to work.

When the soldering is finished take your tape and carefully wrap each exposed wire. Then through each hole put a piece of bushing, and run your connections through the bushings. Run the two ends through for the last lamp. No short wires are attached for these, and your work should now appear as in Fig. 6.

Then you are ready for your lamps. Turn the strip over and fasten the sockets in place, positive sides all on the same edge of your strip. Cut the connecting wires the required length and remove one-half inch of insulation from the ends. Loosen the brass screws, place the ends of the wires under them, and fasten down. Fig. 7 shows one side of socket connected. Attach brass hoops and rubber rings, and you are all ready for placing and connecting. It is probably unnecessary to state that the same principles above explained will enable one to place lights in circles, horseshoes or any other designs that may be required. Once you know how to wire a window, a great field of operations is open to you.

THE FUSE.

The next important step in show window wiring is the proper fusing of circuits. The fuse is to the lighting wire what the safety valve is to the steam boiler. A fuse is composed of a fusible metal, which contains lead, zinc, etc., and becomes fusible at a certain degree of temperature. The fuse is supposed to be “the watch dog” of safety. Ninety-five per cent of the electrical fires are caused by improper fusing.

My advice to the amateur is to apply to the nearest office of the National Board of Fire Underwriters for a copy of the rules on incandescent wiring. They may be obtained for the asking.

THE TRANSFORMER.

Usually the electric fluid (?) is conveyed into the building from the alley, where the high tension wires are strung, carrying a pressure of 2,500 to 3,500 volts from this line. By the aid of a “transformer” the current is reduced to a pressure of 110, 105 or 50 volts, as required, entering the building, when it is conveyed to a double-pole switch; that is, a switch which cuts off both positive and negative wires at the same instant.

The “transformer” is a device for reducing the current from one potential or tension to another, and consists of a ring of many turns of insulated wire; the high tension wire is then wound around and through this ring several turns, and the low tension wire carrying the current into the building is wound around the opposite side of the ring in like manner. The difference in pressure is controlled by the number of turns around the ring on either side, as shown.

All the wires being insulated, the reduction is made by “induction” only. The size of the wire makes no difference in the voltage or pressure, but it makes all the difference in the “amperes” or quantity used to supply the building.

The electric light company will supply a sufficiently large wire from transformer to switch; the firm does the remainder of the wiring.

FEEDERS.

From this large double-pole switch (which is the main cut-off) radiate “feeder” wires to the various parts of the building, to supply the lamp circuits. These feeders have to be carefully gauged according to the number of lamps, or rather, amperes, they are required to carry, in order to avoid resistance in the wire; or in other words, must not crowd the carrying capacity of the wire, or the resistance will make the wire hot and might cause fire.

A “feeder” to the circuits for fifty incandescent 16-candle power lamps should be of somewhat higher capacity, say a No. 10 Brown & Thorp Gauge (B. & S. G.) which has a safe carrying capacity of thirty-two amperes or sixty-four 16-candle power lamps, allowing one-half ampere to each lamp; a No. 12 B. & S. G. wire is allowed to carry twenty-three amperes, or about forty-five 16-candle power lamps; No. 13 B. & S. G. wire is allowed to carry sixteen amperes, or about thirty 16-candle power amps.

The “feeder” should have considerably more carrying capacity than is required in order to permit the addition of extra lights, as occasion may require, and to provide for the addition of extra window lights, if there be not a special feeder for the purpose.

The feeder wires are tapped for lamp circuits by a branch block carrying a fuse for the protection of the circuit. The construction and operation of the branch block, or cut-out, will be understood at once on inspection. The fuse here is the important part; it must be of smaller carrying capacity than the wire it is to protect, and not depend upon the amount of current in the feeder; thus, a No. 10 B. & S. G. might be protected with a 20-ampere fuse (forty lamps, sixteen candle power), or with a 25-ampere fuse, leaving a margin of seven amperes, the wire being allowed to carry thirty-two amperes. It will be understood that “open work” is meant in every case, and wires that are concealed are not allowed to carry so much. The No. 12 wire B. & S. G. is allowed twenty-three amperes, and would be protected by fuse of fifteen to twenty amperes capacity.

The lamp circuits from feeders are in many cities restricted to a certain number of amperes, usually six to ten, or say from ten to twenty lamps (sixteen candle power). Each of these circuits must be protected by its own fuse and have an independent switch. All fuse boxes must have their porcelain cover kept on, and no inflammable material allowed near them. “Twin wires,” or two wires encased, are objectionable.

Drop cords are not allowed except for drop lamps, and must be protected by one-ampere fuse in rosette or cut-out. All wires where joined must be soldered—to prevent an arc forming by making the path of the current continuous or tight.

It is well for the beginner to know that a current of 110 volts does not kill, though it might make the recipient seriously ill. Therefore, be careful not to get yourself in the path of the current. Never touch both naked ends or openings in wires at the same time, nor stand upon the ground while working live wires. Always stand on some non-conductor, a dry board, for instance. The inexpert can always protect himself by disconnecting a fuse behind him both sides; or, better, open the “main cut-off” or first switch.

CONNECTIONS.

When your design is wired and set up in your window, your next step is to connect it to your “cut-out.” You will find two wires leading from it; to these you connect the two wires leading from your design.

It is not necessary to solder this connection; simply remove sufficient insulation and twist the wires together tightly.

There is a way to do this that every one should know, and I will tell you how to make a

WESTERN UNION HITCH.

After removing the insulation from the wires at the ends to be connected, bend the wires as in Fig. 1, lay them together as in Fig. 2, then with a pair of pliers hold one side, and with another pair twist the end around the lead wire tightly and closely, as in Fig. 3. When this is done hold the twisted wires with pliers and repeat the twisting process on the other side. This is a perfectly safe connection, and does not waste electricity as does a loose joint.

DIFFERENT VOLTAGES.

Sometimes it happens that your electric system is of higher voltage than you need use in special work; for instance, you may have a 220-volt circuit, whereas 110-volt lamps are amply strong for your work; or again, you have a 110-volt circuit, and want to use a number of small lamps, 1-candle power, for example.

These are usually of lower voltage, fifty-five or thereabouts.

In these instances we resort to a method known as wiring in series, which is done as in Fig. 4.

Of course the number of lamps to a series is to be governed entirely by the voltage, and the trimmer must resort to his own judgment in determining this.

You will see by the diagram in Fig. 4 that you have two lights for each connection with your lead wires, therefore, if using a 220-volt circuit and 110-volt lamps you have each connection using the full 220 volts, otherwise your lamps would soon burn out, as every connection must consume as many volts as your circuit carries.

Special Designs.—These few instructions answer for a single string of lights, such as a circle, arch, cornice, etc., where your leads run uninterruptedly from first to last lamp; but “how about a design that is impossible to wire that way?” you ask. It is simple, and I have made a few diagrams to illustrate the method employed.

You may have a cornice about your windows, and must bring your wires from the corner. Fig. 5 will show how to do it. A cross, or such designs as have two breaks, are wired as in Fig. 6.

Again, you may wish to use more than one design in a window; for example, you may have three circles, one at back and one at either side. Fig. 7 shows the easiest method.

These principles apply to many varieties of designs, and it is only the principles I am endeavoring to make plain.

And now I will give a few hints or, better yet, some don’ts which will be valuable for amateurs.

SOME “DON’TS.”

Don’t be negligent in handling your connections. Insulate every joint, and don’t leave loose joints; they consume too much current.

Don’t cross wires that are insulated without bushing the overlying wires, and never cross uncovered wires.

Don’t bring a wire through the floor or back of window without using clay bushings; that’s what they are for.

Don’t run wires (as in Fig. 8) without using a lamp, or cutting wires where X is marked; it saves a short circuit.

Don’t let the wires to your lamps touch brass, except under the screw.

Don’t attempt to connect your design to your “cut-out” until you are sure your switch is open. You may short circuit yourself. It is not necessarily fatal, but is decidedly unpleasant.

Don’t handle live wires; 110 volts won’t kill you, but through carelessness you may some day touch a stronger circuit. Practice caution.

Don’t leave an uncovered wire to show in your window. If you suspend a design, wrap the wires with the same color as your background.

Don’t imagine you are an electrician because you can run a string of lights. Keep digging away; you’ll learn something every day.

Don’t try to do all kinds of joint soldering by heating the wires merely. When you become a little more accustomed to the work, get a larger tool kit, and among the first things get a soldering iron. In many places it is necessary.

LETTERS IN ELECTRIC LIGHT.

In the following illustrations are shown plans of a sign to be electrically illuminated. The electrical work is necessarily done in the electric working shops, but as many illuminated signs are being used nowadays, the description may be useful to decorators who contemplate putting in something of the kind. In the first figure the letter is on a casing, A, having a back or support carrying incandescent lamps in channels. The form of the letter is sheet metal and is set-screwed to the base piece at the places marked C. The disks B are plate glass colored to conform to the requirements. The commutator is shown in the other figures. In the first, E is a wood cylinder, which turns in bearings, D. F F are spring contractors, and G G wire connections which join those of the lights. Another view is in the next drawing, in which the cylinder is B, bearings D and spring contractors C. The cylinder is driven by a small electric motor, G, through a reduction gear, consisting of a train of wheels or worm gearing, as at F and E. The spring contacts are electrically joined to the terminals of the lights. The terminals are joined by a combined return to one pole of the source of electric supply, and the other pole is connected to the contact pieces. The rotation of the cylinder consequently breaks and joins the circuit as desired, producing alternate changing of the lights and colors, resulting in attractive effects.

THE WEBER COMMUTATOR.

Fig. 1 is end view. H is a wooden cylinder six inches in diameter and twelve inches long (length is optional according to number of lights), this, as well as all other bearings, run on bearings of curtain fixtures. G is pulley wheel connected with reducer in Fig. 3, D are projections of soft rubber ¼ inch thick placed on cylinder H, and work as follows:

When D reaches E it forces E to the left and forms a contact at F F, thus closing the line and causing lamp or lamps to burn. The position of D on cylinder, and length of same, must be determined by the length of time the lamp or lamps continue to burn and when they shall burn.

The distance from A B to B is 5¾ inches, from A C to C is 7¼ inches.

F F are made of spring copper cut in strips ⅜ of an inch wide and bent to shape, then fastened in base with screws and washer.

Fig. 2 shows front view of commutator and needs no explanation. The above can be operated with water, motor or electricity; but where electricity is used it becomes necessary to reduce speed of motor (which is 2,200 revolutions) to about 40 or 50 revolutions; this is done by building the reducer as shown in Fig. 3.

Fig. 3 shows machine made at an outlay of labor only. Procure six tobacco pail lids, join them face to face with screws and you have three grooved wheels. Make axles of curtain poles twelve inches long, then make frame, again using curtain fixtures as bearings.

Attach motor to No. 1, then from axle of No. 1 run belt to No. 2, from axle of No. 2 run belt to No. 3, then attach axle of No. 3 to pulley G on cylinder and you have a machine on which you can operate from 1 to 100 incandescent lamps alternately.

The Weber commutator is very inexpensive, and has been made by a decorator with an outlay of only fifty cents for the three parts.

THE REYNOLDS FLASHER.

The most reliable machine we now have is one manufactured by a Chicago firm, which is perfect in its construction and operation and will not break down or cause danger from sparks. The expense is about fifteen dollars and the adjustment is so easy that any one can operate it.

A CHEAP HUB SWITCH.

No doubt every one has seen revolving wheels, stars, pyramids, spiral stairs, etc., strung with lights, and many have envied the man who had the facilities for this work; but by following these instructions they can make an appliance that will do the work perfectly.

First make a pulley wheel twelve inches in diameter; then make two circles of one-inch wood six inches in diameter; nail together and fasten in exact center of pulley; insulate the 6-inch circles perfectly.

Next take two strips of spring copper three-eighths inch wide, and make two hoops to fit snugly over the insulation and to each hoop fasten a wire eighteen inches long; then put your hoops on your 6-inch circles about one inch apart, taking care to have them even and tight.

Bore a hole through pulley wheel, and run wire from hoop nearest it through hole; then bore a hole through 6-inch circles and pulley, and run the other wire through it. Use bushings in holes, and insulate uncovered wires. Next take two pieces of copper three-eighths inch wide, six inches long, bend in half circles, attach wire to end of each, fasten to a piece of 1×2, so they will form contacts with copper bands on circles.

Fig. 1 shows band of copper, two half circles on 1 × 2, and pulley when finished.

Now suppose you want to use revolving wheel on pivot. Fasten your appliance in center of wheel, run wires from lamps to wires running through pulley and connect them; then when your wheel is in position, fasten piece of wood with two half circles so each presses tightly on one of the copper bands; connect the wires from half circles to wires from switch, and as your wheel revolves you have a steady contact.

Fig. 2 shows front of wheel, and 3 shows wheel from rear with half circles in position.

For a pyramid or such fixtures simply fasten your appliance to bottom or top as serves your purpose best.

Make your work as near perfect as possible, so the half circles never leave the bands, and exercise great care in insulating, for, while neglect does not always result disastrously it is well to be on the safe side.

THE RUBENS DOUBLE-REVOLVING EFFECT.

The idea is novel and simple. The construction of this machine is inexpensive. Go to any machine shop and have them bore out a piece of shafting so that one will fit into the other snugly. The contact plates are made of copper, lined with asbestos, mounted on wooden circles. In fact, the entire machine can be built for $12. There is no limit to designs that can be made for this arrangement. The novelty of two large pieces revolving in opposite directions, apparently from the point of a single shaft, is in itself a worthy attraction in any window. You will observe in photo that there are two pulleys on main shaft, also a countershaft below. One belt is up straight, the other belt is twisted so as to reverse either shaft. The large pulley on the countershaft is the main driver. The belt attached to this pulley leads to your motor or whatever power you wish to employ. This device is safe as well as simple, as you have ample room for cut-outs.

THE TYLER AUTOMATIC SWITCH.

A is a wooden cylinder, twelve inches long and six inches in diameter. B is brush made of three layers of copper, and is screwed down at lower end, No. 1, so as to work as a spring. C is piece of copper one-half inch wide fastened around cylinder, and comes in contact with B, so as to make one feed wire run to switch. D is piece of copper running one-third of the way around, and comes in contact with another brush, E. Then fasten a small piece of wire from C to D that carries the current to No. 2, while E is on copper. The other feed wire is direct from main circuit to window. F is pulley wheel running to reducer. No. 3 is fuse blocks, which can be used and are much safer than without. This switch cost me twenty-five cents. Of course, I am my own electrician. It will cost no more to any one, as it is very simple.

HOW TO MAKE AN ELECTRIC WAVING FLAG.

This would appear to the uninitiated as a hard one to build, yet it is one of the simplest electrical devices to construct.

First ascertain size of flag you want to make, as there is no limit to size. Build the body of your flag of thin boards, say half an inch thick. The next important thing is to outline on your woodwork an exact flag. Be sure you get the requisite number of stars and stripes. You are now ready to proceed to fasten on your sockets. I may further add here, the flag should not be square. Have a wave running through your stripes; saw out your edges (see cut) accordingly. You now have the general outline, as far as the flag is concerned.