The Bennington evening banner. (Bennington, Vt.) 19??-1961, 1912-02-17
ELECTRIC TERMS.
The Units of Measurement and
What They Mean.
AMPERES, VOLTS AND WATTS.

5re&dly Speaking. Ampsrss Indicate
Volume, Velte Measure Pressure and
Watts Show the Rewriting Quantity.
The kilowatt Hour
It has been estimated that the time
and labor wasted by those engaged in
selling electricity In trying to make
their customers understand a kilowatt
would suffice to build a string of pyra-
mids from New York to San Francisco.
writes Allen Hollis. The dlscouraging
feature Of the task Is that after all this
effort the customer still remains igno.
rant and cherishes the delusion that
the method OF electric measurement Is
a devious device for coDceallng nefarl-
Gus practices by the electric light com
panles.
The average American Is perfectly
satisfied TO buy gas by the foot, trans
portation by the mile and telephones
by the month. but watts look suspicious
and kilowatts totally depraved. This
difficulty might have been avoided If
the eminent scientists who tlrst adopt
ed these accurate and TO them conven-
lent terms had been willing to show
the rest Of the world how to compute
electric quantity In feet and inches or
barrels and quarts. Lacking this. peo-
pie are left to struggle with their mys-
terious method of measurements
The kilo is an old friend Tor ancient
enemy. II you Will borrowed from the
metric system.
This leads to the definition Of watt.
But In order to know watts one must
first learn about the two other mem
bers of the family, amperes and volts
Broadly speaking, amperes measure
volume. volts pressure and watts the
resulting quantity.
In order to get tangible idea OF
the ampere. electricity may be COM
pared with water towing through a
pipe. In this illustration the ampere
will represent the volume Of water.
which Is determined by the size OF the
pipe. but this should not be confused
With the size of the electric wire.
which has nothing TO do with the pres
ent problem. The ampere then meas
ures the volume of current flowing In
the wire at a given time. The quaint
ty Of energy flowing will depend upon
the other factor. which Is expressed
In volts.
The volt may be considered the meas.
ure OF pressure or intensity. In the
illustration of water flowing through a
pipe the pressure is commonly express
ed In pounds to the square inch. With
electric energy the same idea is ex'
pressed In volts. 1t Is evident that the
quantity OF water flowing In a pipe OF
a given size will increase as the pres
sure increases In a similar way the
quantity of electricity. increases In ex
act proportion to the electric pressure
of voltage. and this quantity is meas
ured by watts.
The quantity (wattsl of electricity
delivered over a single circuit is the
direct product of the volume amperes
multiplied by the pressure (voltsl. Ii
other words. amperes multiplied BY
volts equals watts
The Illustration serves TO indicate the
theory OF electric measurement X Il
likely. however. 10 be misleading un
less the fact is kept in mind that wa
ter is material. while electricity mani
tests itself only through Its capacity
Of affecting visible things. 1t heat
the filament in an incandescent lamT
and gives Us light. 1t turns our motors
II magnetizes telephone and telegraph
instruments. but always II conceals Ii
own personality.
In order to know what watt &C
tually is 1t is necessary to ascertain
what II will do. A thousand (kilo
watts are the mechanical equivalen
Of one and one-third horsepower-tha
is. mechanical horsepower equal
TAO watts OF energy. Lighting circuits
usually carry 40 to 100 volts. An or
binary sixteen candle power LAM
takes little less than half an amper
In volume and consequently consume
about fifty watts Of current. With tn
tungsten lamp the rating by watts in
stead OF candle power has been intro
duced and bids fair to become univer
sally adopted.
Being thus furnished with a stand
ard OF measurement It is necessar.
only TO multiply the amount employees
commonly called "capacity"l by th
number of hours of use to get the &C
tual quantity consumed In watt hours
The sixteen candle power lamp, wit
Its fifty watts capacity. consumes oft
watt hours each hour II is used. Th
customary unit OF consumption Is tn
kilowatt hour. 1000 watts used on
hour. and the lamp will consume thi
quantity In twenty hours. The oil
binary electric meter ,recording wat
meter, records automatically the nun
Der of kilowatt hours used, being or
Grated by a mechanism which runs a
speed which corresponds to the ca
pacity employed. Rollins Magazine.
VI Bismarck and No. 3.