Magnetic Mass.
A term for a quantity of magnetism. Unit mass is the quantity which at
unit distance exercises unit force.
Magnetic Matter.
Imaginary matter assumed as a cause of magnetism. Two kinds, one
positive and one negative, may be assumed as in the two fluid theory of
electricity, or only one kind, as in the single fluid theory of
electricity. Various theories of magnetic matter have been presented
whose value is only in their convenience.
[Transcriber's note: See "magnet" and Edward Purcell's explanation of
magnetism using general relativity.]
Magnetic Memory.
The property of retaining magnetism; coercive force; magnetic inertia;
residual magnetism.
[Transcriber's note: Small ferrite magnetic donuts were used as computer
main memory from 1950 to 1970.]
Magnetic Meridian.
A line formed on the earth's surface by the intersection therewith of a
plane passing through the magnetic axis. It is a line determined by the
direction of the compass needle. The meridians constantly change in
direction and correspond in a general way to the geographical meridians.
Magnetic Moment.
The statical couple with which a magnet would be acted on by a uniform
magnetic field of unit intensity if placed with its magnetic axis at
right angles to the lines of force of the field. (Emtage.) A uniformly
and longitudinally magnetized bar has a magnetic moment equal to the
product of its length by the strength of its positive pole.
Magnetic Needle.
A magnet with a cup or small depression at its centre and poised upon a
sharp pin so as to be free to rotate or oscillate in a horizontal plane.
The cup is often made of agate. Left free to take any position, it
places its magnetic axis in the magnetic meridian.
Magnetic Parallels.
Lines roughly parallel to the magnetic equator on all parts of each of
which the dip of the magnetic needle is the same; also called Isoclinic
Lines. These lines mark the places of the intersection of equipotential
surfaces with the earth's surface. They are not true circles, and near
the poles are irregular ellipses; the magnet there points toward their
centres of curvature. They correspond in a general way with the
Geographical Parallels of Latitude.
Magnetic Permeability.
The specific susceptibility of any substance, existing in a mass, for
magnetic induction. (See Magnetic Induction, Coefficient of, synonym for
Magnetic Permeability and Magnetization, Coefficient of Induced.)
Synonyms--Magnetic Inductive Capacity--Multiplying Power--Coefficient of
Magnetic Induction.