Heat, Specific, of Electricity.
A proposed term to account for the heat absorbed or given out in
unhomogeneous conductors, by the Thomson effect, or Peltier effect (see
Effect, Thomson--Effect, Peltier.) If a current of electricity be
assumed to exist, then under the action of these effects it may be
regarded as absorbing or giving out so many coulombs of heat, and thus
establishing a basis for specific heat.
Heat Units.
The British unit of heat is the pound degree F--the quantity of heat
required to raise the temperature of a pound of water from 32° to 33° F.
The C. G. S. unit is the gram-degree C.; another metric unit is the
kilogram-degree C. The latter is the calorie; the former is sometimes
called the small calorie or the joule; the latter is sometimes called
the large calorie. The term joule is also applied to a quantity of heat
equivalent to the energy of a watt-second or volt-coulomb. This is equal
to .24l gram degree calorie.
Hecto.
A prefix to terms of measurement--meaning one hundred times, as
hectometer, one hundred meters.
Heliograph.
An apparatus for reflecting flashes of light to a distant observer. By
using the Morse telegraph code messages may thus be transmitted long
distances. When possible the sun's light is used.
Helix.
A coil of wire; properly a coil wound so as to follow the outlines of a
screw without overlaying itself.
Fig. 194. LEFT-HANDED HELIX.
Fig. 195. RIGHT-HANDED HELIX.
Henry.
The practical unit of electro-magnetic or magnetic inductance. It is
equal to 1E9 C. G. S., or absolute units of inductance. As the
dimensions of inductance are a length the henry is equal to 1E9
centimeters, or approximately to one quadrant of the earth measured on
the meridian.
Synonyms--Secohm--Quadrant--Quad.