(a) The number of ampere turns, q. v., required to bring an iron core to
one half its magnetic saturation, q. v., is termed the diacritical
number.
(b) The diacritical point of magnetic saturation is proposed by Sylvanus
P. Thompson as a term for the coefficient of magnetic saturation which
gives a magnet core one-half its maximum magnetization.

Wound in the direction or sense of a right-handed screw; the reverse of
sinistrotorsal, q. v.

Deviation of the compass in iron or steel ships due to vertical
induction. (See Induction, Vertical.) The effect of this induction
disappears when the ship is in the electric meridian. Its name is
derived from the fact that a swing of the ship through half the circle
brings the needle from zero deviation to a maximum and back to [...]

Deviation of the compass in iron or steel ships due to the magnetization
of horizontal beams by the earth’s induction. The effect of this
deviation disappears when the ship is in the plane of the electric
meridian, or at right angles thereto; its name is taken from the fact
that a swing of the ship through a quadrant brings [...]

A portable galvanometer with a high and a low resistance actuating coil,
constructed for the use of linemen and telegraph constructors when in
the field, and actually putting up, repairing or testing lines.

A portable galvanometer, often of simple construction, used for rough or
approximate work.

A press or push button, with small flush rim, for setting into the
woodwork of a desk.

A point where a circuit branches or divides into two or more leads. The
separate branches then receive derived or partial currents.

The metal or other substance precipitated by the action of a battery or
other current generator.

(a) The removal of permanent magnetism.
(b) The prevention of the polarization of a galvanic cell. It is
effected in the Grove battery by the reduction of nitric acid; in the
Bunsen, by the reduction of chromic acid; in the Smee battery,
mechanically, by the platinum coated or rather platinized negative
plate. Other examples will be found under the description [...]