The development of new magnetic properties or alteration of magnetic
sensibility in a body by heat. Nickel and iron are much affected as
regards their paramagnetic power by rise of temperature.

Pyrometer, Siemens’ Electric.
An instrument for measuring high temperatures by the variations in
electric resistance in a platinum wire exposed to the heat which is to
be measured.

A current generator producing electric energy directly from thermal
energy by pyromagnetism.
Edison’s pyromagnetic generator has eight electro-magnets, lying on
eight radii of a circle, their poles facing inward and their yokes
vertical. Only two are shown in the cut. On a horizontal iron disc are
mounted eight vertical rolls of corrugated nickel representing
armatures. On each armature a coil of [...]

A motor driven by the alternation of attraction and release of an
armature or other moving part, as such part or a section of it is
rendered more or less paramagnetic by heat.
Thus imagine a cylinder of nickel at the end of a suspension rod, so
mounted that it can swing like a pendulum. A magnet pole is [...]

A phenomenon by which certain minerals when warmed acquire electrical
properties. (Ganot.) The mineral tourmaline exhibits it strongly. It was
originally observed in this mineral which was found to first attract and
then to repel hot ashes.
The phenomenon lasts while any change of temperature within certain
limits is taking place. In the case of tourmaline the range is from
about [...]

A switch for closing a circuit by means of pressure applied to a button.
The button is provided with a spring, so that when pushed in and
released it springs back. Thus the circuit is closed only as long as the
button is pressed. The electric connection may be made by pressing
together two flat springs, each connected to [...]

A form of mechanical air pump for exhausting incandescent lamp bulbs.
Referring to the cut, A is a bulb on the upper part of a tube G; above A
are two other bulbs C and D. From the upper end a tube runs to the bulb
E. Through the cock L, and tube F connection is made with [...]

A form of mercurial air pump. A simple form is shown in the cut. Mercury
is caused to flow from the funnel A, through c d to a vessel B. A side
connection x leads to the vessel R to be exhausted. As the mercury
passes x it breaks into short columns, and carries air down between
them, in [...]

In incandescent lamps a periodical recurring change in intensity due to
bad running of the dynamos, or in arc lamps to bad feeding of the
carbons.

A form of mercurial air pump. It is used for exhausting Geissler tubes,
incandescent lamp bulbs and similar purposes.
Referring to the cut, A is a reservoir of mercury with flexible tube C
connected to a tube at its bottom, and raised and lowered by a windlass
b, the cord from which passes over a pulley a. When raised [...]

A switch for closing a circuit when pulled. It is used instead of a push
button, q.v., in exposed situations, as its contacts are better
protected than those of the ordinary push button.