Evening star. [volume] (Washington, D.C.) 1854-1972, 1912-08-04

country buy gas or electricity as regu-
larry as they buy bread or potatoes. Yet
there is not one in a thousand Of these
people who have any knowledge OF the
yardstick that is applied to this power
when a piece of it Is torn off and sold
over the producers counters. The stand
ard cell is the yardstick that is used in
measuring any given voltage The stand
ard cell equals 1.O1SS volts, and any volt
age may be measured by comparing it
with a standard cell.
1t would take a scientist six months to
manufacture himself standard cell for
accurate scientific measurement Yet he
may buy a cell from any manufacturer.
send it to the bureau of standards. have
it measured and its divergence from the
standard noted, and then may use 1t free
~. correcting his calculations in accord
ance with its variation. The ability to
do this makes all scientific research in
electricity standard and makes possible
an interchange Of findings on a basis of
the same fundamental quantities
Another matter that enters into all
electrical computations is the resistance
Of the wires over which current is trans
mitted. International conferences have
established an Esperanto measurement
of this resistance. The amount of re-
sistance that an electric current would
meet in passing through given column
Of mercury is called an "ohm." 1t is
standard term used everywhere.
But the meter which weighs out the
amount of electricity that a householder
is using comes most nearly to the inter-
est of the. multitude. Meters are based
primarily upon the ability actually to
weigh a current of electricity. The cur
rent is actually put on the scales and
weighed. This is the way 1t liz done
Two coils OF insulated wire are used.
These are placed in such a way as to
give the positive and negative qualities
of the electrodes an opportunity to at
attached to a scale and the pull of the
attraction or repulsion are actually
measured. The size of the coils, etc 4.
being known, the actual force OF tine cur
rent is thus weighed
When the current being transmitted is
of immense size, as in the ease OF
large consumer, 1t Is impracticabie to
run that current through a meter. In
these cases a transformer is used. The
great current is run through II. frac-
tionaI percentage Of 1t is cut Off most
accurately and this fraction is measured.
Then il is used as basis upon which TO
compute the entire current.
The ordinary meters seen around power
houses. where there is a hand :. at indi-
Gates the power of the current. are built
upon this principle. They are splitting
off a given percentage of a strong cur
rent and computing the whole automat-
ically. 1t Is the quality of attraction or
repulsion of the electrical magnet that
causes the hand Of the meter to move
along the dial.
It is important to the electrical indus
try that its different appliances should
be standard as well as its measures Me-
tiers are generally uniform as are trans
formers. There is no short-weighting in
the electrical business. There is no at
tempt to give current that is less than
that represented The effectiveness of an
electrical business depends upon the cor
rectness of its measures. There is no
reason why q manufacturer should turn
out fourteen-candlepowerl lamp where
sixteen Is ordered. for the one costs as
much as the other. II would be dam
serous business for a power company to
install its plant on the basis of deceiv
ing it's patronage a. 10 the current fur
nished. for that deception would be most