The tendency of molecules to resist rotation or change of position; the assumed cause of magnetic coercive force, or retentivity.

The induction coil, q. v.

In a mariners’ compass, the thirty-two points, designated, north, north by east, north north east, etc. (See Compass Mariner’s-Compass, Points of the.)

A petroleum product; a hydrocarbon of low boiling point. Its vapor is used in flashing (q. v.) carbon filaments for incandescent lamps.

A pole changer, current reverser, or commutator, g., such as the commutator of an induction coil. (Obsolete.)

An automatic circuit breaker, one which rapidly opens and closes a circuit, as in the case of the primary of an induction coil an interrupter. (Obsolete.)

This apparatus consists of two cylinders, one, A, made of brass, the other, B, of wood, with a spiral groove. At its end is a copper ring a. A fine brass wire has one end attached to this ring. Its other end is fastened at e, and it is wound as shown; n and o [...]

An apparatus for increasing potential difference. It consists of a number of static condensers. They are charged in multiple arc or in parallel, and are discharged in series. Secondary batteries may be used for the charging; thus a static effect is produced from a galvanic battery.

The third arm of known resistance in a Wheatstone bridge. (See Proportionate Arms.)

An adjustable resistance; an apparatus for changing the resistance without opening the circuit. Its action may depend on the introduction of variable lengths of mercury column, of some other liquid, or of wire into a circuit. (See Rheostat, Wheatstone’s.)