The silver state news. [volume] (Winnemucca, Nev.) 1907-1909, 1909-01-19

All matter is believed to be made
nm of minute particles called mole
cules According to the kinetic the
orv of matter, these molecules are in
rapid but irregular motion (like a
.varm of bees.) To increase the We
,oe;tv of these molecules is to warm
the body; TO decrease their velocity
ia 70 cool the body. There are many
ways in which body may be warmed.
r. we rub coin vigorously upon the
Garnet. we set its molecules in more
rapid motion and soon perceive that
we press on the coin, the greater is
its motion but the more heat is deveI-
oped.
Among the many ways of develop
ing heat in body is to pass current
of electricity through it. All the elec-
tric energy that is used up in over
coming the resistance of its current
is converted into heat energy. After
much experimental work, Joule,
great English physicist, found that
the amount of heat developed by an
electric current could be accurately
calculated. He announced the law
that the number of heat units devel-
oped within conductor is proportion
alto Q) the time the current flows,
f2l TO the resistance of the circuit,
and (3) to the square of the current
strength.
In developing heat, increase of cur
rent strength is, consequently. of
greater Importance than increase Of
resistance. A circuit that has twice
the resistance but the same current
strength as another is developing heat
twice as fast as the second whereas a
circuit that has twice the current
strength but the same resistance as
another is developed heat four times
as fast as the other.
II will be remembered that when
the pressure or electro motive force
remains constant Gas it is supposed 70
do in our incandescent lamps) the cur
rent strength or size Of current is in
versely proportional to the resistance
il must overcome If / lessen the re-
sistance in circuit to one-half wha.
il was at first, twlce as great eu--
rent is allowed TO pass through.
Would the change have any effect up
on the amount of heat developedf BY
making the resistance oDe-half as
great, the heat would he developed
one-haf as fast, but in making the
veloped four times as fast. The net
effect of the change is, therefore, TO
develope the heat twice as fast. II
is thus seen that the less resistance we
put in any circuit having constant
pressure, the greater is the heat de
veloped (and the greater the amount
of power eonsumed.)
An ordinary electric laundry iron
consumes about times as much
power as 16 candle power lamp. 1t
offers only one-eighth the resistance
to the current that the lamp offers
and so its current is eight times as
large.
We have thus far assumed that the
electro motive force or voltage re
mained constant. Since, however, "A
change in voltage makes a proportion
ate change in current strength, we
may readily calculate its effect. Let
us take common case as an illustra-
uon. Suppose person should buy a
fiat'ron for use on l10-volt current
and should afterwards move to city
where the current was run at 220-volt
pressure; with twice the voltage. he
would receive twice the current that
MS iron was designed for and used on
TINS current it would soon burn out.
II the reverse happened and he at
tempted to use 220-volt iron on a
iio'volt current, he would find that
ne could scarcely get his iron more
yuan luke warm. This is why all
makers of electric heating devices
caution intending purchasers to nj
ways state voltage desired. Some
tlmes their descriptive catalogues give
rating. "Voltage 100 to125." From
consideration Of the foregoing prin.
ciples, 1t will be seen that this does
not mean that the device is for opera.
uon on any voltage between. II
merely that the article is made for
any OF the various intermediate volt
ages but that it is necessary to speci
~ the exact voltage desired. Appai
atus will not give satisfaction if con
nected to circuits of voltages varying
more than per cent from that mark