Induction, Magnetic. The magnetization of iron or other paramagnetic substances by a magnetic field. The magnetic influence of a bar excited under these conditions is shown by throwing iron filings upon it. They will adhere to both ends (that is at the negative and positive poles) but not at the middle.
Inductor. A mass of iron in a current generator which is moved past a magnet-pole to increase the number of lines of force issuing therefrom. It is generally laminated, and is used in inductor dynamos and motors of the alternating-current type.
Influence, Electric. Electric induction or influence which may be electro-static, current, or electro-magnetic.
Influence Machine. A static electric machine worked by induction, and used to build up charges of opposite nature on two separate prime-conductors.
Installation. The entire apparatus, building, and appurtenances of a technical or manufacturing plant or power-house. An electric-light installation would mean the machinery, street-lines, lamps, etc.
Insulating Joint. Used for the purpose of insulating a gas-pipe from an electric circuit.
Insulating Varnish. A varnish composed of insulating material, such as gums, shellac, or diluted rubber. Shellac dissolved in alcohol is perhaps the best. It is easy to make and dries quickly, making an insulating surface practical for almost every ordinary use.
Insulation. The dielectric or non-conducting materials which are used to prevent the leakage of electricity. The covering for magnet wires, and overhead conduits for power lines and electric lighting.
Insulation, Oil. Any non-combustible oil may be employed as an insulator to prevent electrical leakage in induction-coils, transformers, and the like. Its principal advantage lies in its being in liquid form, permitting of easy handling. Moreover, if pierced by a spark from a coil, it at once closes again without becoming ignited. A solid insulator, if pierced, is permanently injured.
Insulator. Any insulating substance or material to prevent the escape of current. The knobs of porcelain or glass to which wires are made fast.