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Igniter. A mechanical hand apparatus, in which a battery, induction-coil, and vibrator are located, and whose spark, jumping across a gap at the end of a rod, ignites or lights a gas flame, blasting-powder, or dynamite.
I-H-P. An abbreviation for indicated horse-power.
Illuminating Power. Any source of light as compared with a standard light—as, for instance, the illuminating power of an electric light reckoned in candle-power.
Illumination. A light given from any source and projected on a surface, per unit of area, directly or by reflection. It is stated in terms—as, for instance, the candle-power of a lamp. When speaking of an incandescent lamp we say it illuminates equal to four candle-power or it gives a light equal to sixteen candle-power.
Immersion, Simple. Plating, without the aid of a battery, by simply immersing the metal in a solution of metallic salt.
Impulse. The motion produced by the sudden or momentary action of a force upon a body. An electro-magnetic impulse is the action produced by the electro-magnetic waves in magnetizing a mass of soft iron and attracting to it another mass of iron or steel.
An electro-motive impulse is one where the force rises so high as to produce an impulsive discharge such as that from a Leyden-jar.
Incandescence, Electric. The heating of a conductor to red or white heat by the passage of an electric current. For example, an incandescent lamp.
Incandescent Circuit. (See [Circuit, Incandescent].)