Staunton vindicator. [volume] (Staunton, Va.) 1860-1896, 1892-06-10
ELECTRICAL TERMS.
A LUCID EXPLANATION OF THE
LAWS OF ELECTRICITY.

IA LUCID EXPLANATION OF THE
| LAWS OF ELECTRICITY.
If One Understands the Flow of Water
as Seen In the Ordinary Househ old
bend the Flow of the Electric Current
Probably few people when turning on q
water lancet in their house, or playing a
hose ir their garden, ever realize that the
laws controlling the flow of water have a
great similarity to those governing the
suptler fluid. electricity; and whether they
turn Oh faucet or an electric light GER
tain conditions exist and certain actions
follow which are analogous
The water in The faucet is under GER
tain pressure, and an amount of water
flows out Of the faucet dependent upon this
pressure and upon the size of the faucet
| An electric current in a wire is under a
certain pressure, and an amount of current
flows through the wire dependent upon
the pressure and upon the size of the wire.
In a garden hose, water under good
pressure, if allowed to escape through a
small nozzle, will be forced considerable
distance. In an incandescent lamp, cur
rent under a fair pressure is allowed to es-
cape through the minute filament of the
lamp, heats the filament to incandescence
and throws out beams of light. Not that
electricity is fluid in the sense that water
is. or that there is any actual transference
Of matter when current passes through a
wire, as there is when water flows through
pipe; but there is close analogy be-
tween the laws governing the two, and it
is just as easy and as simple to predict the
actions of one within certain range of
conditions as it is of the other
The great trouble has been that electri-
clans have thrown a veil Of mystery over
their calling by naming all their units
after French and German celebrities. This
has led to no end of confusion. Volts,
alnperes, ohms, watts, joules and coulom BIS
are becoming common words in print in
these days of great electrical activity, but
they express about as much meaning to
| the average person as Chinese laundry
mans sign.
Pounds, quarts and the rest of our every
day units of measurement are familiar to
every school child; so will volts and am
peres be some day when the American peo-
| PtC e1C bCtCCl ttSl udillUcO W UI Uuo 0OIuSS
of these distinguished foreigners and the
units their names now represent.
Alexander Volta was a professor of
physics in Pavia who accomplished great
deal in a scientific way; consequently cleo
tricians not only erected a marble tablet to
his memory, but agreed to name the cleo
trical pound per square foot after him, and
SO the unit of electrical pressure is the
wolf SiyY,i n rIyy 1oI 70
our electrical gallon with an accent over
the last syllable of ainpere Ohm has
had his name used as the unit of electrical
resistance ever since he gave to the world
his celebrated law on the flow of current.
Ohm said that the amount of current going
through copper wire was proportioned
to the pressure under which this current
worked and to the size of the WIRE
This is not very different from what any
body's common sense would see was true
of water flowing through hose The
amount Of water is Of course proportional
to the pressure under which it works and
to the size of the hose. Ohm made great
reputation on this discovery, and since his
time other people have been finding out
that what is true of water is also analo-
gously true Of electricity. Look at ali
electric road A wire carrying current is
stretched through the air and all man
has to do to move car containing 100 peo-
Pile along street is to connect the car
machinery with the wire by pole.
If the wire was pipe carrying water
under considerable pressure and this
pipe could be connected to the car by
movable hose, a water motor would make
the car move just as the electric motor
does, and moreover, the water would flow
through the pipe, and the hose, and the
motor to the ground falling from con-
siderable pressure to zero pressure Just as
the current flows through the wire, aud
the trolley arm and the motor to the
ground falling from 500 volts pressure to
zero pressure or potential as it may be
called, which is the potential of the earth
just as the zero potential of water is the
sea level. Moreover, as a certain number
OF gallons of water will flow through the
pipe, the hose and the motor, dependent
upon the size of the pipe, the hose, and the
motor and the pressure of the water, so
will certain number of amperes of cur
rent flow through the trolley wire, the
trolley arm and the motor winding de-
pendent upon the size of tho wire In them
all and the electrical pressure of the cur
rent.
A line of electric arc lights are made to
burn by inserting them one after the other
in series in a line carrying current of high
pressure, and the passage Of the current
through each Light uses up a certain per-
oentage of this pressure just as series of
water wheels may be introduced in brook
or a river where each wheel will similarly
use up certain amount of the pressure of
the running water.
Incandescent lights are burned without
affecting the pressure in two wires run par
allel to each other by connecting the two
terminals of each lamp to the wires and
allowing the current to pass through their
tilaments, just as two water pipes running
parallel to each other may be punctured
with small holes wherever it is desired to
have the currents of water escape In
neither case will the pressure be diminished
at any point, except by an inconsiderable
amount due to friction, though large
quantity of water or electric fluid will be
Used.
A mans body offers a resistance to the
passage of an electric current dependent
upon the muscular and nerve fibers of the
body, the thickness of his skin and the con
ditions under which the current enters and
leaves his body. This resistance depends,
therefore, upon three variable factors, and
therein lies the uncertainty of "electrocu-
tion." A mans ability to withstand the
effects Of a waterfall depends similarly
upon the strength Of the man and the point
of application of the waters force Here
are two variable facts which can be disre-
garded SO long as we have Niagara falls
This would seem to be an argument in ia
vor Of ''hydrocution.
All electrical current phenomena have
their exact parallel in the flow Of water,
apd for the ready explanation of the one it
is only necessary to understand the other.
Everybody understands their water fau-
GETS, though they may not understand their
plumber. So should people understand the
common uses Of the mysterious current,
though they do not comprehend the useless
and perplexing technicalities of expert cleo
tricians.-New York World.
NI,o,,oos of owl noo+l,