Ground (electricity)

“ The same occurs if the metallic point be fixed on the electrised conductor, and the finger of a person standing on the ground be presented to it, the accumulated electricity will pass off at a much greater distance, and indeed will soon discharge itself by communicating the accumulated electricity to the atmosphere. ”

“ At a certain distance from the point the resultant force is not sufficient to break through the insulation of the air, so that the electric current is checked, and the electricity accumulates in the air round the point. ”

“ By this plan the current is increased in intensity, for the “earth circuit” appears to offer less resistance than the copper wire. The view, however, which regards the earth not as a conductor in the same sense as the wire, but as the great reservoir or storehouse of electricity, accords better with known facts. ”

“ On the Rio Grande River in Colorado they are constructing several plants where water power will be utilized to generate electricity for use more than one hundred and fifty miles away. For transmitting electricity to such a distance they step up the voltage, or electro-motive force as it is called, to 100,000 volts. ”

“ If the surface is quite plane the repelling force between the elementary particles of the charge is parallel to the surface, and there is no component tending to flake electricity off the surface and disperse it into the air. If the surface is curved there is such a component, and it becomes the greater the more sharply the surface is curved. At a sharp corner it becomes very great, and if the corner is drawn out into a sharp point the force is so great that all the charge is dissipated as soon as brought to the conductor. ”

“ Thus we have two bodies—the cloud and the earth—charged with opposite kinds of electricity, and separated by a stratum of the atmosphere. The two opposite electricities powerfully attract each other; but for a time they are prevented from rushing together by the intervening stratum of air, which is a non-conductor of electricity, and acts as a barrier between them. ”

“ Now the very definition of a conductor is a body over the surface of which electricity can distribute itself without hindrance, that is to say, only under the influence of the potential force that pushes it. The region of space surrounding the charged in which the potential has a sensible value is called the "electric field." A unit charge brought into any point of this field will experience a force acting in a certain direction; in the case of the field being due to the presence of a charged sphere the force acts either radially outward from or radially inward to the centre of the sphere. ”

“ In endeavoring to adapt currents or discharges of very high tension to various valuable uses, as the distribution of energy through wires from central plants to distant places of consumption, or the transmission of powerful disturbances to great distances, through the natural or non-artificial media. I have encountered difficulties in confining considerable amounts of electricity to the conductors and preventing its leakage over their supports, or its escape into the ambient air, which always takes place when the electric surface density reaches a certain value. ”

“ If the extreme surfaces be now discharged, these internal charges will gradually be dissipated, and a certain charge may reappear on the extreme surfaces if they are insulated, or, if they are connected by a conductor, a certain quantity of electricity may be urged through the conductor during the reestablishment of equilibrium. ”

“ An electric current manifests itself by heating the wire or conductor, by causing a magnetic field around the conductor245 and by causing chemical changes in a liquid through which it may pass.
Note.—Statics is that branch of mechanics which treats of the forces which keep bodies at rest or in equilibrium. Dynamics treats of bodies in motion. Hence static electricity is electricity at rest. The earth’s great store of electricity is at rest or in equilibrium. ”

“ These lines of force must all terminate somewhere, either on bodies in the neighbourhood, or on the walls and roof of the room, or on the earth, or on the heavenly bodies, and wherever they terminate there is a quantity of electricity exactly equal and opposite to that on the part of the body from which they proceeded. ”

“ Now, electricity is a very exact science. There is no mere theory about it; and a unit is a definite quantity of power, known in that science as a “kilowatt hour.” Thus, a kilowatt, or 1,000 watts, is the equivalent in measured work of 11⁄3 horse-power, equal to the lifting of 44,000 lbs. per minute, or the doing of so many units of work, either electric lighting, heating, machinery driving, or traction. ”

“ Some improvement seems yet to be wanting at both extremities of the rod—at the upper extremity, to secure it against the accident of being melted, which renders it afterwards unfit to answer its original intention, viz. drawing off the electricity, or lightning, from the passing cloud, in a silent imperceptible manner, for it is only pointed conductors that possess this property—and at the lower extremity, to afford a more ready passage for the fluid into the surrounding earth. ”

“ Ritchie's paper, from which the following are extracts: "Common electricity is diffused over the surface of the metal;—voltaic electricity exists within the metal. Free electricity is conducted over the surface of the thinnest gold leaf as effectually as over a mass of metal having the same surface;—voltaic electricity requires thickness of metal for its conduction," p. ”

“ The electrical poles live in eternal animosity, because they have no point of union. Such is then the essence of electricity. Electricity is therefore only a function of surfaces without any line. It clings only to the upper surface of the bodies, and does not penetrate into their thickness. It is only the tension of the surfaces of bodies against each other, of the apices of divided radii.
414. The air is the periphery, the limit or boundary of the earth. ”

“ If the lower conductor is very far from its surface will be very nearly plane, so that we have here the solution of the distribution of electricity on two surfaces, both of them nearly plane and parallel to each other, except that the upper one has a protuberance near its middle point, which is more or less prominent according to the particular equipotential line we choose for the surface. ”

“ A wooden sphere covered with the thinnest layer of gold-beater's skin will at the same potential hold exactly the same quantity of electricity as if it were made of solid brass or lead or any other metal. Electricity at rest resides entirely on the outside of a metal conductor. We might reduce the thickness of a shell to any degree, and still the charge is not altered. ”

“ The whole space in which a distribution of electricity produces any action on electrified bodies is called the electrical field of the distribution. The force exerted on a very small insulated trial conductor, on which is an electric charge of amount equal to that taken as the unit quantity of electricity, measures the field-intensity at any point at which the conductor is placed. ”

“ The theory completely accounts for the theorem of Art. 77, that the total induction through a closed surface is equal to the total quantity of electricity within the surface multiplied by 4. For what we have called the induction through the surface is simply the electric displacement multiplied by 4, and the total displacement outwards is necessarily equal to the total electrification within the surface. ”

“ Priestley states that the German electricians generally used several globes at a time and that they could excite such a prodigious power of electricity from “globes, whirled by a large wheel and rubbed with woollen cloth or a dry hand, that, if we may credit their own accounts, the blood could be drawn from the finger by an electric spark ”

“ 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. ”

“ As the inclination was increased, the electricity became more powerful until the angle formed by the plane of the plate with the dip was 90°, when the electricity for a given velocity of the plate was a maximum. ”

“ It is in many cases impracticable, from the interruption of rocks or other obstacles, to sink the rod so deep as to reach moist earth, or any other substance which is a tolerably good conductor of electricity. ”

“ If a system in which the distribution of electricity is known is placed in the neighbourhood of a conducting sphere of radius , which is maintained at potential zero by connexion with the earth, then the electrifications due to the several parts of the system will be superposed. ”

“ 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. ”

“ So that you have mechanical power, electricity, and heat; mechanical power and heat being the two extremes of the circuit.
“When you have electricity developed, the connection of heat and light is necessarily accompanied by resistance to the passage of the electricity. The action of lightning conductors, for example, is entirely dependent upon that fact. The chimneys that the conductors protect offer resistance to the passage of the discharge, and therefore would be destroyed by that discharge ”

“ Hence it appears that the electricity discharged from an electrified conductor is more powerful than that discharged from an electric—the conductor acquiring a large quantity of electricity from an electric, by receiving it gradually, spark after spark, and afterwards, when touched, discharging it all at once.
The velocity of electricity is almost beyond conception. ”

“ Surging Character of High-tension Currents.—When a current of electricity is sent through a wire, hundreds of miles in length, the current surges back and forth on the wire many thousands of times a second. Light comes to us from the sun, over 90,000,000 of miles, through the ether. ”

“ The Electric Field is the portion of space in the neighbourhood of electrified bodies, considered with reference to electric phenomena. It may be occupied by air or other bodies, or it may be a so-called vacuum, from which we have withdrawn every substance which we can act upon with the means at our disposal. ”

“ Can we conduct from one place to another this peculiar state of things, this queer form of potential energy which we call electrification? It is clear, from the last experiments, that in order to do it we need something besides ebonite, which really acts like a closed stop-cock to the flow of electrification.
To keep electrification in one place we need an insulator; to get it from one place to another we need a conductor. Insulators are as important as conductors. ”

“ We may apply the method of inversion to deduce the distribution of electricity on an uninsulated sphere under the influence of an electrified point from the uniform distribution on an insulated sphere not influenced by any other body. ”

“ After demonstrating the practicability of this method of transmission, the thought naturally occurred to me to use the earth as a conductor, thus dispensing with all wires. Whatever electricity may be, it is a fact that it behaves like an incompressible fluid, and the earth may be looked upon as an immense reservoir of electricity, which, I thought, could be disturbed effectively by a properly designed electrical machine. Accordingly, my next efforts were directed toward perfecting a special apparatus which would be highly effective in creating a disturbance of electricity in the earth. ”

“ Under certain conditions the force of attraction may be sufficiently great and the distance sufficiently small to cause electricity to leap across the intervening space, and then we have the familiar phenomenon of an electric spark. ”

“ Whether electrification is produced by friction or by contact, the process is in either case the separation of charges of electricity of opposite sign. We know that such charges attract each other, and that if accumulated on conductors sufficiently near, the conductors themselves will experience an attracting force. The tendency will be to bring the conductors together, and if they are held firmly in place, the tendency will be for the charges themselves to leave the conductors and unite. ”

“ To understand this, we may consider, that if a person standing on the floor would draw off the electrical atmosphere from an electrified body, an iron crow and a blunt knitting kneedle held alternately in his hand and presented for that purpose, do not draw with different forces in proportion to their different masses. ”