The Bennington banner. [volume] (Bennington, Vt.) 1858-1894, 1892-04-29
TO MEASURE BY METER,

| number of merchants and consumers of
the lights in town have, as a cheaper
way out of it, come to the conclusion to
put in meters &c measure the exact
amount of fluid which they use and
thereby pay for their lights in that Way.
Fol the benefit of those who are inter
ested in these matters we print the fol-
lowing explanation of the method which
is used to measure the light in this man
ner and description of the little meter:
Open one of the meters of the Edison
company and you will find that it con-
sistS of two compartments; in the upper
you will find a piece of German silver
running in zigzag line across the COM
partment; in the lower compartment,
separated from the upper by bar, the
latter being part of the cast iron con-
struction of the meter, there is spool
of copper wire and bottle; in the latter
there are two pieces of zinc, separated
from each other by means of piece of
rubber. These three things constitute
the meter. Some meters contain two of
each kind, and are called double meters,
being capable of doing double the work
done by single meter.
The principle underlying the measur-
ing is that of electrOplating. The latter
is done by means of an electric battery, "a
piece of copper being placed in the bat
terry on the opposite pole or wire, and
the object to be plated being placed on
the negative wire; by the action of the
electricity the copper is eaten away
from the positive wire and deposited on
the article fastened to the opposite wire.
In the electric light meter two pieces of
zinc are used; this zinc must be chemi-
cally, pure that the measurements
may be perfectly correct. These two
pieces of zinc ale separated by rubber
and joined by rubber bolts, so that they
may be near each other and still not
permit of passing of the electric current.
One piece represents the positive pole,
the other the negative pole. Now, the
more electricity passes through these
pieces of zinc the more zinc will be taken
from the positive to the negative pole, so
that if enough electricity is used, in
course of time all the zinc would be on
one pole. Here you have the principle
of measuring electricity. After the
pieces of zinc have been in operation for
some time one will weigh more than the
other, and it is just a matter of mathe-
NAUTICAL calculation how much is charged
the charge being relative to the amount
of zinc decomposed.
But if the bottles were all that was
".
would require a bottle the size of house
to measure the electricity used in the
average residence or store, and the con-
sumption of zinc would be something
enormous. 1t is for this purpose that
the piece of German silver is used, this
metal being selected as best fitted for
the purpose. This piece of metal is
called a shunt, because it stunts off
most of the electricity and prevents it
from going through the bottle.
This piece of metal is so accurately adj
justed that it takes just 900 parts of
electricity to one which passes through
the bottle; the electricity from the cleo
trio light wire, before it goes to the
lamps, passes through the meter; here
one-thousandth part passes through the
bottle with Its piece of zinc, the rest be-
ing shunted off through the German sill
yer. 1t is on this account that the size
of the bottle may be reduced to small
dimensions.
The spool of copper wire is fixed be-
tween the wire and bottle. When the
solution of sulphate of zinc contained in
the bottle gets too warm, it permits
more electricity to pass through it than
the one-thousandth part of the whole.
At the same time the increase in temper
allure would have an opposite effect on
the German silver, and less would pass
through. This would result in a heavy
registering, the amount of zinc con-
sumed being proportiOnately large, and
would be an injustice to the consumer.
In order to avoid this the spool of cop
per wire is used. When the bottle gets
too warm the copper wire is similarly
affected. The copper does not permit
the bottle to gobble up all the electricity
it would like, and thus acts rs a regula-
tor.
During the last days of the months the
employees of the Edison company 90
about among the customers of the COM
pany gathering in all the bottles and re-
placing them by others. These bottles
are all carefully marked and taken to the
office of the company. Here the pieces
of zinc are separated and the negative
pieces, which are indicated by being OPP
posite to where the head of the rubber
bolt is, are carefully washed and then
permitted to dry.
After this their record is looked up,
and the operator knows just to milf
gram how much each piece of zinc
weighed before it left the works and was
put in the meter. On one of the most
nicely adjusted scales the zinc is weighed
and the difference in its weight noted
down. This decrease of weight is null
tiplied by figure known as the con-
slant, and the result is the bill of the
consumer in dollars and cents.
OF course the zinc removed from the
positive pole is deposited on the mega
tive, and the amount of electricity used
might be ascertained by weighing the
negative piece and noting the increase in
weight. But this would not be accur-
rate, as some of the zinc in process of
being transferred from pole to pole is
lost in the solution; besides that, to de-
termine the amount of electricity used
in this way would give way to fraud on
the part of few consumers who under
stand electricity. There is no likelihood
of their scraping the positive pole, for
the more they scrape it the higher would
their bill be.
1t is but natural that only the best
adjusted scales can be used in the weigh
ing of these pieces of zinc. In the first
place, before the weighing is done, every
door and window is closed, although the
weighing is done in an inside room; the
least bit of air would add several dollars
to some customers bill. Then the scales
are covered with glass, and it is only
when the piece of zinc has been placed
on the scales and the glass lowered that
the weighing is proceeded with.-Sun-
day NeUOS.