Electrification

“ Now if any portion of electricity could be forced into a body so as to be absorbed in it, or to become latent, or in any way to exist in it, without being connected with an equal portion of the opposite electricity by lines of induction, or if, after having being absorbed, it could gradually emerge and return to its ordinary mode of action, we should find some change of electrification in the surrounding vessel. ”

“ This true electrification must be distinguished from the apparent electrification , which is the electrification as deduced from the electrical forces in the neighbourhood of the surface, using the ordinary characteristic equation
If a solid dielectric of any form is a perfect insulator, and if its surface receives no charge, then the true electrification remains zero, whatever be the electrical forces acting on it. ”

“ II. When one body electrifies another by conduction, the total electrification of the two bodies remains the same, that is, the one loses as much positive or gains as much negative electrification as the other gains of positive or loses of negative electrification. ”

“ We cannot walk across a dry carpet, or run the hand along a piece of furniture, without producing some slight electrification which has the effect of setting up potential differences between different points of space, and, as the merest trace of such a potential difference suffices to start the cumulative process, machines of the Wimshurst type generally start without the necessity of previous electrical excitation. ”

“ But we have proved, in Art. 76, that the surface-integral of the electrical force taken over any closed surface gives the total electrification within that surface multiplied by 4. Now, in this case the force is everywhere outwards, so that the surface-integral is necessarily positive, and therefore there is positive electrification within the surface, and, since we may take the surface as near to as we please, there is positive electrification at the point . ”

“ Where currents of any magnitude are required, we must use other methods of producing electricity. These will be discussed subsequently, but for the present it is important to note that, apart from a question of degree, the frictional machine is an apparatus whereby electric currents may be generated.
How does the matter stand with regard to electrification by contact between solid bodies? Can we thereby also produce an electric current? We have seen that two metals in contact electrify each other. Using copper and zinc, the former becomes negatively and the latter positively electrified ”

“ He showed that all substances could be electrified by friction, but that to electrify conductors they must be insulated or supported on non-conductors. Various improvements were made in the electrical machine, and thereby experimentalists were provided with the means of generating strong electrification ”

“ It will be observed that the segments of both discs, whilst passing each other on the horizontal diameter, are charged with electricity of the same sign, namely, positive on the left and negative on the right.
If we now inquire as to the true cause of electrification, we find that apart from the quite insignificant initial charge on A and B, it is simply the mechanical energy required to produce rotation against the opposing force of electrostatic attraction between the outer and inner segments. A has a positive, and a has a negative charge. ”

“ We have seen that the actions of electrified bodies are such that the electrification of one body may be equal to that of another, or to the sum of the electrifications of two bodies, and that when two bodies are equally and oppositely electrified they have no electrical effect on external bodies when placed together within a closed insulated conducting vessel. We may express all these results in a concise and consistent manner by describing an electrified body as charged with a certain quantity of electricity, which we may denote by . ”

“ He named the result produced, electrification, after the Greek name for amber (elektron) . A body like hard rubber or amber which will attract light objects when rubbed is said to be electrified, or to have been given a charge of electricity.
214. Law of Electric Action.—Let a vulcanite rod be electrified by rubbing with a woolen cloth until it will attract light objects; then place it in a wire stirrup suspended by a silk thread. If a second vulcanite rod is similarly electrified and brought near the first, the two [Pg 244] will be found to repel. (See Fig. 186.) ”

“ It is this energy which, by the action of the machine, is converted into the potential energy represented by the electric field surrounding the two electrodes. To increase the charge it is customary to connect the electrodes with the knobs of two Ley den jars, since by the use of a condenser the quantity of electricity, which can be accumulated with a given difference of potential, is greatly augmented. That energy is used in producing electrification is distinctly felt when working the machine by hand. ”

“ Thus in paper-making machinery, where the band of paper passes at high speed over hot metal rolls, it may become electrified to the extent of sparking and igniting itself. To avoid this danger it is necessary to fix spiked combs, which draw off the charge as soon as generated. In all these cases the electricity produced by friction is only an inconvenient by-product of some other operation; but if we wish to produce electricity for experimental work we may use special appliances based on the principle of electrification by friction. ”

“ If the question be absurd, then all the phenomena witnessed in bodies, large or small, are due to the fact that the atoms are not inert, but are immensely energetic, and their inertia is the measure of their rates of exchanging energy.
THE ETHER IS CONDITIONALLY POSSESSED OF INERTIA.
A moving mass of matter is brought to rest by friction, because it imparts its motion at some rate to the body it is in contact with. Generally the energy is transformed into heat, but sometimes it appears as electrification. Friction is only possible because one or both of the bodies possess inertia. ”

“ It was at first the chemist who emancipated electricity for new and myriad uses. His successor to-day is the engineer, who wins his spurs by bringing his generator to practical perfection, by improving his steam and gas engines to double their efficiency of thirty years ago. If to the engineer and mechanic the electric art owes much, magnificently has the debt been repaid. As we discover in replacing at our street door an old-fashioned moving bell pull by an electric wire armed with a push button, electricity transmits motion without movement of its conductor as a mass. ”

“ Since electricity is of all phases of energy the easiest to preserve from losses resembling leakage or friction, the current can not only be distributed throughout the largest workshop with convenience and economy, it can be sent to the shop from an engine or a water wheel many miles away, as in connecting motors at Buffalo to dynamos at Niagara, twenty-seven miles distant. With the transmission of electricity for distances vastly exceeding twenty-seven miles we have long been familiar in the telegraph. ”

“ When they were changed to electric cars, electricity became the successful rival of nothing else than a twisted wire cable. The cars still run by steam power as before, but that power is transmitted by electricity instead of the discarded cable. Steam has driven out the horse as a power for drawing street cars, and electricity has enabled us to gather all the steam engines into central stations, where now they are furnishing the power for moving surface, elevated, and subway cars for street traffic, as also trains for suburban travel. ”

“ The electrical transmission of power is exemplified in everything which is based on the generation of electricity. The ordinary electric light is power coming from a generator in the building or a public street-dynamo.
However, when we talk in general terms of electric transmission we mean the transmission of energy on a large scale by means of overhead or underground conductors to a considerable distance and the transformation of this energy into light and heat and chemical or mechanical power to carry on the processes of work and industry. ”

“ Indeed, electricity has always disported itself there in the lightning, jumping from cloud to mountain peak as I have seen it nowhere else on earth.
The next time I saw the boys they had ambitious plans indeed. The penstock at the mill was to be repaired. The water-wheel was to drive an alternating current dynamo. The voltage of this current was to be stepped up by a transformer. It was to be transmitted to the cottage and there the e. m. f. was to be stepped down again by another transformer. My wife suggested that if it interfered with the simple life it would have to step down and out. ”

“ As regards the nature of electricity, though innumerable observations have been made during the nineteenth century and a vast multitude of facts put upon record, we know little more than is above stated. But if we turn to the practical applications of electric power, it is to find these standing high among the great advances of the century. To it we owe the highly important discoveries of the telegraph and the telephone; the conversion of engine power into electricity by the dynamo and the use of this in moving cars, carriages and machinery ”

“ When they are worked from a power station the great advantage is gained that the same plant which drives them can be used for many other purposes, such as working machine tools and supplying current for lighting. For dock-side jib cranes the use of electric power is making rapid strides. For overhead travellers in workshops, and for most of the cranes which fall into our second class, electricity as a motive power has already displaced nearly every other method. ”

“ It is evident that while our energy would dwindle continually we should never quite come out of the little end of the horn, since any number may diminish by 20 per cent. of itself indefinitely.
"Let us get at something practical," said Erg. "How are we going to furnish electricity to the cottage when the dynamo is not running? If we put a storage battery at the cottage, how are we going to store it having nothing but alternating current up there; and if we attempt to transmit current from our central station battery, how are we going to get along with the drop in the voltage?" ”

“ As the first essential of a successful electric railway is a plentiful supply of cheap power, development from the experimental stage of Portrush had to wait until engineers mastered the art of producing electricity from large generators. ”

“ In the explanations which are given of electric tramways, electric railways, electric automobiles, electric propulsion on ships, and the other phases of electric traction, nothing but the most elementary knowledge of electricity is presupposed. ”

“ Motor generators are frequently used as boosters to raise or boost the voltage near the extremities of long distance, direct current transmission lines. Of these, electric railway systems in which it is desired to extend certain of the longer lines, form a typical example. ”

“ Between the petrol-driven vehicle and the electric automobile there is an interesting series of links provided by 'petrol-electric' systems.
At one end of the chain, electricity plays an important part in supplying power to drive the car. At the other end, electrical apparatus is introduced merely as a form of transmission gear between the petrol engine and the driving axle. ”

“ The generator of the electric current, which is stored away in some out-of-the-way corner, is probably a small so-called "dry-cell" which you could readily carry around in your pocket; or it may consist of a receptacle holding a pint or two of liquid in which some metal plates are immersed. Such an apparatus seems scarcely more than a toy when we contrast it with the gigantic dynamos of the power-house; yet, within the limits of its capacities, one is as surely a generator of electricity as the other. ”

“ Every one knows now that electric lights are produced from powerful currents of electricity generated in a machine containing magnets and coils of wire, and driven by a steam engine, or gas engine, or water-wheel. But of the thousands who have heard that a steam engine can thus provide us with electric currents, how many are there who comprehend the action of the generator or dynamo-electric machine? ”

“ It was predicted by George Stephenson in 1825 that his system would supersede all other methods of conveyance in this country. Similarly can it now be prophesied that throughout the world electrical traction will ultimately supplant all other forms. An age of electricity is dawning, when “power” may be obtained direct from fuel or from the vast store of energy existing in the heated interior of the earth, or even from the atmosphere that surrounds us ”

“ From the before mentioned law of electricity, that points, as they are more or less acute, draw on and throw off the electrical fluid with more or less power, and at greater or less distances, and in larger or smaller quantities in the same time, we may see how to account for the situation of the leaf of gold suspended between two plates, the upper one continually electrified, the under one in a person's hand standing on the floor. When the upper plate is electrified, the leaf is attracted and raised towards it, and would fly to that plate were it not for its own points. ”