Armature-bar. An armature in a dynamo or motor whose winding is made up of conductors in the form of bars.
Armature-coil. The insulated wire wound around the core of the armature of an electric current-generator or motor.
Armature-core. The central mass of iron on which the insulated wire is wound; it is rotated in the field of an electric current-generator or motor.
Armored. Protected by armor; as cables may be surrounded by a proper sheathing to guard them from injury.
Astatic. Having no magnetic directive tendency, the latter being a general consequent of the earth’s magnetism.
Astatic Circuit. (See [Circuit, Astatic].)
Astatic Couple. (See [Couple, Astatic].)
Astatic Needle. A combination of two magnetic needles so adjusted as to have as slight directive tendency as possible. The combination is generally made up of two needles arranged one above the other with the poles in opposite directions—commonly called “Nobili’s Pair.” These needles require but a slight electro-force to turn them one way or the other, and are used in astatic galvanometers.
Atmospheric Electricity. (See [Electricity, Atmospheric].)
Atom. The ultimate particle or division of an elementary substance. Electricity is largely responsible for the presence of atoms in the atmosphere.