(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 [...]

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 [...]

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 [...]

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 [...]