One of the two kinds of electric charges. The other is the positive. By the double fluid hypothesis this is assumed to be a charge of a particular kind of electricity–negative electricity. By the single fluid hypothesis it is supposed to be caused by the absence of part of the normal electricity of a surface. [...]

The index in needle telegraphy (see Telegraph, Needle), whose motions indicate the characters it is desired to transmit.

The magnetic needle poised horizontally, and used for measuring the intensity of the earth’s magnetic field, or of an artificial magnetic field, by the method of oscillations. The intensities of the field is inversely as the square of the number of oscillations performed in a given time.

(a) A term applied to a bar magnet poised horizontally upon a vertical point, or suspended in a horizontal position by a filament. Thus the magnet in a mariner’s compass, which may be a substantial bar magnet, is called a magnetic needle. (b) An indicator in general shape like the hand of a clock. (Sec [...]

A term for earth currents. (See Current, Earth.)

An element just separating from a combination possesses at that time higher affinities than after separation, and can effect more powerful chemical changes. It is sometimes attributed to a differential time of existence in the atomic modification, before the freed atoms have united to form molecules.

A series of logarithms the base of whose system is 2.72818. They are also called hyperbolic logarithms.

The cylinder electrical machine, q.v.

(a) Symbol for north pole or north-seeking pole of a magnet. (b) Symbol for the number of lines of force in a magnetic circuit.