Electrical equipment

“ Every one knows that when by means of an ordinary electrical machine electricity has been generated in sufficient quantity and under suitable conditions to prevent its dispersion, a spark of intense brilliancy and greater or less length, according to the amount of electricity thus collected, can be obtained when some body, not similarly electrified, is brought near to what is called the conductor of the machine. ”

“ The electrical machines in common use are composed of a hollow glass cylinder, or circular plate of glass, turning on an axis, and rubbing against two or more leather rubbers covered with silk, the electricity being collected by sharp points fixed in a metal rod standing on a glass pillar. ”

“ It is not our purpose here to describe at length the electrical machine, but we may state that it consists of two parts, one for generating electricity by means of the friction of a rubber against glass, and another consisting of a system of brass tubes, of considerable surface, supported on glass stems, for collecting and retaining the electricity so produced. This latter part of the machine is called its prime conductor. ”

“ In the infancy of the science no country produced more electricians than Germany; in the discovery and exposition of its subtlest laws, as well as in their application to useful purposes, no country has done more than England; while in the most novel and most extensive use of electrical appliances for industrial purposes the New World may be said to have outstripped the Old. ”

“ Replace it, and let the cylinder be again wiped; the machine is fit for use.
4. Sometimes the electric matter will not be well collected, because the machine is not sufficiently supplied with it from the earth; which happens, when the table upon which the electrical machine is placed and to which the chain or wire of the rubber is connected, is very dry, and consequently a bad conductor. In this case, the best method is to connect the chain or wire of the rubber with some moist ground, or with the iron-work of a water-pump, if convenient. ”

“ CHAPTER LIII.—THE ELECTRICAL MACHINE, AND HOW TO MAKE IT. In our chapter on the Leyden Jar we assumed that those of our readers who were likely to experiment in frictional electricity would be in possession of an electrical machine to start with. Many, however, may be desirous of building an electrical machine of their own. ”

“ ELECTRIC TOY MAKING, DYNAMO BUILDING, AND ELECTRIC MOTOR CONSTRUCTION. By PROF. T. O'CONOR SLOANE. This work treats of the making at home of electrical toys, electrical apparatus, motors, dynamos and instruments in general, and is designed to bring within the reach of young and old the manufacture of genuine and useful electrical appliances. The work is especially designed for amateurs and young folks. Thousands of our young people are daily experimenting, and busily engaged in making electrical toys and apparatus of various kinds. ”

“ On account of this very low electrical pressure all danger from the current is eliminated and the apparatus may be handled with the same freedom as any ordinary metal-working machine. In the distribution of the electrical appliances the current is usually generated by a machine conveniently located with reference to the source of power, and the current carried by wires to the welders, where the transformation takes place, each welder being provided with its own converter, proportioned so as to supply the character of current best suited to the special work of the machine. ”

“ Form a communication by a chain from the coating to the cushion, and the phial will charge.
For the globe then draws the electrical fire out of the outside surface of the phial, and forces it, through the prime conductor and wire of the phial, into the inside surface. ”

“ If the electrical stand be kept clean and dry, a man standing on it when such clouds are passing low, might be electrified and afford sparks, the rod drawing fire to him from a cloud. If any danger to the man should be apprehended (though I think there would be none) let him stand on the floor of his box, and now and then bring near to the rod, the loop of a wire that has one end fastened to the leads, he holding it by a wax handle; so the sparks, if the rod is electrified, will strike from the rod to the wire, and not affect him. ”

“ Frictional electrical machines can be purchased from any electrical instrument makers, at a small price, and with these experiments mentioned are more readily performed. In this article I only mention experiments that can be performed with materials to be found in every house, or the necessaries for which can be procured from a shop for a nominal sum. ”

“ While the company has never undertaken the wiring of residences, ordinary apartment houses, or accepted any like contracts, it repairs anything electrical from an electric iron to a 500 horse-power electric motor. ”

“ Fig. 175. The Leyden jar and brass wire discharger.
Thirty-sixth Experiment.
The jar is silently discharged if the balls are removed from the discharger and points used instead; so, also, the whole of the electricity produced by an electrical machine in full action may be readily drawn off by a pointed conductor, such as a needle, placed at the end of a brass wire. Electricity passes much more rapidly through points than rounded surfaces, hence the reason why all parts of electrical apparatus are free from sharp points and rough asperities. ”

“ The rapid progress that has been made of late years in the application of electricity to industrial purposes, and particularly in the transmission of power by means of the electric motor, has made it imperative for every engineer who wishes to keep up to date to have some knowledge of the way electrical currents are controlled and used for practical purposes. ”

“ If the needle can be soldered to a metal stand, or the cork covered with tinfoil, the wire is not needed. On rubbing the paper and placing it on the tray, the electricity passes up the wire into the needle, thence into the wire cross, and escapes by the bent portions of the wires, each of which should be filed to a point. In escaping it electrifies the surrounding air, and this, according to the law that “like electricities repel each other,” has a reacting force on the wire arms. Accordingly the windmill begins to turn, and may attain a tolerable rate of speed if the tray is strongly charged. ”

“ Having described the electrical machine, we are now to consider some of the phenomena attending its operation. When the prime conductor receives electricity from the cylinder, it is said to be electrified by communication, and it then acts in every respect like the cylinder itself, except that the latter, when touched by a conductor communicating with the earth, gives a considerable number of sparks before it is discharged; whereas the conductor discharges itself by a single spark. ”

“ All wires and current carrying parts should be kept far enough apart at all points to prevent accidental contact or the jumping across of the 428 current where there is a great difference of voltage. Such wires should be also kept at a sufficient distance from screw heads, metal brackets, gas pipes, water pipes, and other conducting bodies, in order to prevent accidental grounds or short circuits. ”

“ Now, if you grasp the outside of the coated end with one hand, and touch the knobbed wire with the other, you will receive a shock.
96In this experiment, the coated part of the tube answers the double purpose of the electrical machine and Leyden phial; the uncoated part serving as a handle, to hold the instrument by. The friction on the outside accumulates a quantity of positive electricity upon it, and this electricity, in virtue of its sphere of action, forces out a quantity from the inside. ”

“ Do not leave your electrical installation entirely to your architect. Watch what is happening. Remember you need as many outlets as you possibly can afford; the more you have the better lighting you can have, the better electric comforts you can have. If you have few outlets you are very prone to overload your circuit, and in the future as more electric devices come into being you will have to pass them up. Outlets consume no electricity but are simply entrances where electricity can be located as soon as the appliance is connected up with it and turned on. ”

“ Their powers may be enormously increased by covering them with amalgam, as sold in the electrical shops, but a far better plan is to cover the cushions with tinfoil, which can be glued right round the rubbers and over the backs. ”

“ The spread of electric light and power lines through the country constitutes a boon that makes possible the use of all kinds of electrical appliances known in the city, including refrigerators, cooking ranges, washing machines, water pumps, water heaters and hundreds of other machines and appliances, some of which are in their infancy. No great difficulty is experienced in locating in the open country where such electrical facilities are available. ”

“ THE ELECTRIC TRUMPET.
There are many toys which one meets with in the scientific stores, the making of which for themselves would give great satisfaction to enterprising devotees of the electrical art. They are for the most part easily constructed, and a great deal of amusement can be derived from them. I have my doubts whether the fathers and mothers of the amateur electrician will thank me for introducing the subject of the present article, but they must take comfort in the thought that if it works well it shows real constructive power on the part of the maker. ”

“ In consequence of the rapid development of that part of electrical science which may be termed "heavy electrical engineering," reliable measuring instruments specially suitable for the large currents employed in lighting and transmission of energy have become an absolute necessity. As usual, demand has stimulated supply, and many ingenious and useful instruments have been invented, the manufacture of which forms at the present day an important industry. ”

“ In discharging electrical jars, the electricity goes in the greatest quantity through the best conductors, and by the shortest passage. Thus if a chain and a wire be made to communicate at the same time with the outer coating of a jar, and be both presented to the knob of that jar, the greater part of the charge will pass by the wire, and very little by the chain, because the latter is a worse conductor than the former, on account of its discontinuation at every link. When the discharge is 29made by the chain only, sparks are seen at every link, which is a proof they are not in contact. ”

“ The motor frames, the entire frame of the crane and the tracks must be permanently and effectively grounded.
A number of recommendations were made calling for conductive coatings on cables, outlet boxes and fittings in order to secure better electrical contact at all points throughout systems in which they are used. ”

“ The annunciator has a bell to call attention. A cable of six wires enters this annunciator (Fig. 36) . One wire goes direct to the bell and the other five reach the bell through the separate coils of the electro-magnets which control the drops. But how are [70] electrical connections made between a moving elevator car and the push buttons on various floors? The diagram in Fig. 37 shows this in elevation. B represents a battery of several dry cells located in the basement. One wire from it runs direct to the push buttons 1, 2, 3, 4, 5, located upon the five floors of the house. ”

“ In the electrical machines already described sparks occur whenever the carrier comes in contact with a conductor at a different potential from its own.
Now we have shewn that whenever this occurs there is a loss of energy, and therefore the whole work employed in turning the machine is not converted into electrification in an available form, but part is spent in producing the heat and noise of electric sparks. I have therefore thought it desirable to shew how an electrical machine may be constructed which is not subject to this loss of efficiency. ”

“ The alternating current will operate incandescent lamps, arc lamps, electric heating apparatus, alternating current motors. It will flow through a straight wire with slightly increased retarding effect, but if the wire be wound on an iron bar its strength is greatly reduced. ”

“ All electrical machines and batteries are merely instruments for moving electricity from one place to another, or for causing electricity, when accumulated in one place, to do work in returning to its former level of distribution.
The head or pressure in a standpipe is what causes water to move through the pipes which offer resistance to the flow.
Similarly, the conductors, along which the electric current is said to flow, offer more or less resistance to the flow, depending28 on the material. Copper wire is generally used as it offers little resistance. ”

“ Q shows a stout wire or strip of 2 or 3 thicknesses of tin. Suppose we have an apparatus, as, for example, an electric bell, which we want to have ring when someone at a distance desires to call us. If we use a telephone or telegraph instrument we shall want to cut the bell out of the circuit as soon as we hear the call and are ready to talk. Suppose the current comes to us through the wire, A, Fig. ”

“ The Plate Electrical Machine. Fig. 7 also shows an old form of machine. Such machines are made of circular plates of glass or ebonite, two rubbing pads being usually employed, one on each side of the plate. One operator is seen on an insulated stool (Fig. 7) , the electricity passing through him before entering the earth by way of the body of the man at the right.
Fig. 8.
11. The Toepler-Holtz Machine, in one form, is shown in Fig. 8. The electricity is produced by the principle of induction, and not by mere friction. This machine, used in connection with condensers, produces large sparks. ”