Wood County reporter. [volume] (Grand Rapids [i.e. Wisconsin Rapids], Wis.) 1857-1923, 1893-02-16
I Simple Explanation Which
Should be OF Interest to ALI
Laymen.
The Flow of Water Qnite SINH
lar to That Of Electric
Currents.
Origin OF Terms Volt and Ohm =
Resistance of the Body to
Electricity.

ElfCtflCliy.
Probably few people when turning on
water faucet in their house, or playing
hose in their garden, ever realize that
the laws controlling the flow of water
have a great similarity to those govern
ing the subtler fluid electricity; and
whether they turn on a faucet Or an
electric light, certain conditions exist
and cetain actions follow which are an
alagous.
The water in the faucet is under a
certain pressure, and an amount of wa
ter 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 depend
ent upon the pressure and upon the size
of the wire.
pressure, If allowed to escape through
a small nozzle, will be forced consid-
cradle distance. In an incandesecnt
lamp, current under a fair pressure is
llowed to escape through the minute
filament of the lamp, heats the filament
to incandescence, and throws ont beams
Of light. Not that electricity is 4 fluid
in the sense that water is, says the New
York World, or that there is any actual
transference Of matter when current
passes through a wire, as there is when
water flows through a pipe; but there
Is a close analogy between 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 1t is Of the other.
The great trouble has been that cleo
tricians have thrown a veil of mystery
over their calling by naming all their
units after French and German celebri-
ties. This has led to no end of confu-
sion. Volts, ampers, Ohms, waite, dulles
and coulombs 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 a Chinese laundryman's sign.
Pounds, quarts and the rest of our
everyday units of measurement are IA
miliar to every school child; so will volts
and amperes be some day when the
with the doings of these distinguished
foreigners and the units their names now
represent.
Alexander Volta was professor of
physics in Pavia, who accomplished a
great deal in a scientific way; cOnSe-
quently electricians not only erected a
marble tablet to his memory, but agreed
to name the electrical pound per square
foot after him, and so the unit of cleo
trical pressure is the volt. Similarly
we are compelled to write our electri-
cal gallon with an accent over the last
syllable after ampere. 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 a 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
anybody's common sense would see
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 a great reputation on this
discovery, and since his time other peO-
pie have been finding out that what is
true of water is also analogously true
of electricity. Look at an electric road!
A wire carrying current is stretched
though the al and all a man has to do
to move a car containing 100 people
along street is to connect the car ma
chinery with the wire by a pole. If
the wire was pipe carrying water I'M
der considerable pressure and this pipe
could be connected to the car by NOV
able hose a water motor would make
the car move just as the electric mo-
tor does. and moreover the water would
flow through the pipe, and the hose
and the motor to the ground, falling
from considerable pressure to zero
pressure, just as the current flows
through the wire and the trolley arm
and the motor to the ground, falling
fom 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 certain number Of gal
Ions of water will flow through the pipe,
the hose and the motor, dependent up
on the size Of the pipe, the hose and the
motor and the pressure Of the water,
so will a certain number of ampereS
of current flow through the trolley wire,
the trolley arm and the motor winding,
dependent upon the size of the wire in
them all and the electrical pressure of
the current.
! A line of electric arc lights are made
to burn by inserting them one after thee
other in series in line current of a
high pressure, and the passage of the
current through each light uses up a
certain percentage of this pressure just
/ series OF water wheels may be intro
duced in a brook or river where each
wheel will similarly use up a certain
amount Of the pressure Of the running
water.
Incandescent lights are burned with
out affecting the pressure in two wires
run parallel to each other, by connect
ing the two terminals of each lamp to
the wires and allowing the current to
pass. through their filaments just as
two water mines running naranpl to