A typewriter in which the work of printing or of pressing the type faces
against the paper, or printing ribbon, is done by electro-magnetic
attraction. The keys close electric circuits, throwing the
electro-magnetic action into play. This involves the use of electricity
for what is ordinarily only a mechanical process. The strength of the
impression, however, is independent of the [...]

The ampere-turns on the secondary circuit of an induction coil or
transformer. These depend on the path provided for the current. If of
negligible inductance, such as a number of incandescent lamps would
provide, the ampere-turns should be equal to those of the primary coil.
(See Turns, Primary Ampere.)

The ampere-turns in a primary circuit of an induction coil or
transformer. In an electric welding transformer, or in the transformer
used in the alternating current system, where efficiency is an important
element, the ampere-turns in primary and secondary for an efficiency of
100 per cent. should be equal. In the case of an experimental induction
coil other considerations outweigh [...]

The rotations of a dynamo armature while it is building itself up or
exciting itself. The expression is a bad one, as it is likely to be
confounded with the dead turns of armature wire.

An expression applied to the convolutions of wire in a solenoid,
electro-magnet, or other apparatus or construction of that kind. A turn
indicates a complete encircling of the core or axis of the object. Thus
a wire wound five times around a bar gives five turns.
While this is its primary meaning the term if compounded may refer to
virtual [...]

A braid woven of tissue or worsted, and tubular or hollow. Its object is
to provide a covering which can be drawn over joints in covered wires.
In making the joint the ends of the wires are necessarily bared, and a
short piece of tubular braid is used for covering them. It is drawn by
hand over the joint.

A tube of glass around which is pasted a series of tinfoil circles,
diamonds, or little squares, or other form of interrupted conductor. The
pieces generally are placed in the line of a spiral. When a static
discharge of electricity takes place along the conductor a row of bright
sparks is produced at the breaks in the conductor. These [...]

In telephone distribution systems, the lines connecting different
stations, or different sections of a switch-board and used by anyone
requiring such connections; one trunk line answers for a number of
subscribers.

A telephone switchboard arranged in sections, which sections are
connected by trunk lines, through which trunk lines the desired
connections are made.

An apparatus consisting of a vibrating tongue, kept in motion by
electricity as in the buzzer, q. v., placed in the small end of a
trumpet-shaped tube.