E
Earth. The accidental grounding of a circuit is termed an “earth.”
Earth-plate. A plate buried in the ground to receive the ends of telegraph lines and other circuits, and so give a ground connection. Copper plates are often used, but in houses the ground is usually formed by attaching a wire to the gas or water pipes.
Earth Return. The grounding of a wire in a circuit at both ends gives the circuit an earth return. This method is commonly used in telegraph lines, both in the wire and wireless systems.
Eddy Currents. (See [Currents, Eddy].)
Edison Distributing-box. A box used in the Edison “three-wire” system, from which the outlets pass to local circuits.
Edison Lalande Cell. A zinc-copper battery having a depolarizing coating of copper oxide on the copper element, the couple being immersed in an electrolyte composed of potash or caustic soda.
Ediswan. A term applied to the incandescent lamps invented by Edison and Swan and used extensively in Great Britain. Also applied to other apparatus designed by the two inventors.
Efficiency. The relation of work done to the electrical energy absorbed. The efficiency is not equal to the energy absorbed, because it always takes more power to generate a current than is given back in actual efficiency. This is due to mechanical friction and to the resistance of the air in a mechanism such as a dynamo when revolving at high speed.
Efficiency, Electrical. In a generator it is the total electrical energy produced, both that wasted and that actually used in driving machinery or apparatus.
Efflorescence. The dry salts on a jar or vessel containing liquid that collects above the water or evaporation line. This is due to creeping.
Elasticity. A property in some bodies and forces through which they recover their former figure, shape, or dimensions when the external pressure or stress is removed. Water has no elasticity. Air is very elastic; steam has a great volume of elasticity; while electricity is undoubtedly the most elastic of all in its motion through air, water, and other conducting mediums.
Electric. Pertaining to electricity; anything connected with the use of electricity. It has been a much-abused word, and its meaning has been garbled by the impostor, the crook, and the “business thief” in foisting on the public wares in which there was no electrical property whatever. “Electric” toothbrushes, combs, corsets, belts, and the like may contain a few bits of magnetized steel, but they possess no active therapeutic value.
Electrical Engineer. The profession of electrical engineer calls for the highest knowledge of electricity, both theoretical and practical. It embraces the designing and installation of all kinds of electrical apparatus.
Electrician. One versed in the practices and science of electricity; a practical lineman or wireman.
Electricity. One of the hidden and mysterious powers of nature, which man has brought under control to serve his ends, and which manifests itself mainly through attraction and repulsion; the most powerful and yet the most docile force known to man, coming from nowhere and without form, weight, or color, invisible and inaudible; an energy which fills the universe and which is the active principle in heat, light, magnetism, chemical affinity, and mechanical motion.
Electricity, Atmospheric. The electric currents of the atmosphere, variable but never absent. They include lightning, frictional electricity, the Aurora Borealis, the electric waves used in wireless telegraphy, etc. Benjamin Franklin indicated the method of drawing electricity from the clouds. In June, 1752, he flew a kite, and by its moistened cord drew an electric current from the clouds so that sparks were visible on a brass key at the ground end of the cord. Later, when a fine wire was substituted for the cord, and a kite was flown in a thunder-storm, the electric spark was vivid. This experiment confirmed his hypothesis that lightning was identical with the disruptive discharges of electricity.
Electricity, Latent. The bound charge of static electricity.
Electricity, Negative. (See [Negative Electricity].)
Electricity, Positive. (See [Positive Electricity].)
Electricity, Voltaic. Electricity of low potential difference and large current intensity.
Electricity produced by a voltaic battery or dynamo as opposed to static electricity, which is frictional and practically uncontrollable for commercial purposes.
Electrification. The process of imparting an electric charge to a surface. The term is applied chiefly to electro-static phenomena.
Electrization. In electro-therapeutics, the subjection of the human system to electric treatment. An electric tonic imparted by electro-medical baths through the nervous system.
Electro-chemistry. That branch of science which treats of the relations between electric and chemical forces in their different reactions and compounds. It deals with electro-plating, electro-fusing, electrolysis, etc.
Electro-culture. The application of electricity to the cultivation of plants. The use of electricity has been found very beneficial in some forms of plant growth.
Electrocution. Capital punishment inflicted by electric current from a dynamo of high electro-motive force. The current used is from 1500 to 2000 volts, and it acts to break down the tissues of the body.
Electrode. The terminals of an open electric circuit.
The terminals between which an electric arc is formed, as in the arc-light.
The terminals of the conductors of an electric circuit immersed in an electrolytic solution, such as the carbon and zinc of a battery.
Electrolier. A fixture for supporting electric lamps, similar to a chandelier for gas or candles. Combination electroliers conduct both gas and electricity.
Electrolysis. The separation of a chemical compound into its constituted parts by the action of an electric current.
Electrolyte. A body susceptible of decomposition by the electric current. It must be a fluid body and a conductor capable of diffusion as well as composite in its make-up. An elemental body such as pure water cannot be an electrolyte.
Electrolytic Decomposition. (See [Decomposition, Electrolytic].)
Electrolytic Deposit. (See [Deposit, Electrolytic].)
Electrolytic Resistance. (See [Resistance, Electrolytic].)
Electro-magnetic Induction. (See [Induction, Electro-Magnetic].)
Electro-magnetism. Magnetism created by electric current.
That branch of electrical science which treats of the magnetic relations of a field of force produced by a current.
Electro-medical Bath. A bath provided with connections and electrodes for causing a current of electricity to pass through the body of the patient.
Electrometer. An instrument used for measuring static electricity. Electrometers are different from galvanometers, since the latter depend on a current flowing through wires to create an action of the magnetic needles.
Electro-motive Force. Voltage. It may be compared to the pressure of water in hydraulic systems. The unit of electro-motive force is the volt.
Electro-motor. A term sometimes applied to a current-generator, such as a small dynamo or voltaic battery.
Electro-plating. (See [Plating, Electro].)
Electropoion Fluid. An acid depolarizing solution for use in zinc-carbon couples, such as the “Grenet” and “Daniell” cells. The bi-chromate-of-potash and sulphuric-acid solution for battery charges is a good example.
Electroscope. An apparatus for indicating the presence of an electric charge and whether the charge is negative or positive.
Electrostatic Accumulator. Two conducting surfaces, separated by a dielectric and arranged for the opposite charging of the two surfaces. A faradic or static machine for accumulating frictional electricity is an example.
Electrostatics. That division of electric science which treats of the phenomena of the electric charge, or of electricity in repose, as contrasted with electro-dynamics or electricity in motion.
Electrotype. The reproduction of a form of type or engraving by the copper electro-plating process. The original is coated with plumbago and a wax impression taken of it. The face of the negative is made conductive with plumbago or tin dust, then suspended in a copper bath and connected with the current. A film of copper will be deposited on the face of the wax impression.
Element, Chemical. Original forms of matter that cannot be separated into simple constituents by any known process. There are about seventy in all, but as science advances the list is constantly being revised. New elements are discovered and known ones are being resolved into simpler forms.
Elements of Battery Cell. (See [Battery Cell, Elements of].)
Emergency Switch. An auxiliary switch used as a controller on a car to reverse the action of the motor.
E-M-F. An abbreviation for electro-motive force, or voltage.
Equalizer. A term applied to a wire or bar in electro-magnetic mechanism for equalizing the pressure over a system.
Exciter. A generator used for exciting the field-magnets of a dynamo.
Extension Call-bell. A bell connected with a telephone call-bell, and located in another part of a building so as to give a distant summons.
External Circuit. (See [Circuit, External].)