Southern standard. (McMinnville, Tenn.) 1879-current, 1889-03-09
THE ELECTRIC LIGHT.
An Explanation Of Our NeW HUNT
ndnt, and HOl0 II Is Produced.

EDITOR STANDARD: Owing to the
deep interest many of your citizens
have manifested in the installation of
your electric light plant, / trust you
will spare me little space in your
valuable columns, through which
medium l will endeavor to give some
information which might prove of in
terest to some of your readers.
The electricity is produced with the
aid of a dynamo, where an armature,
that is coil of copper wire fastened
to an axis, revolves close to powerful
magnets. The ends of this armature
are fastened to copper pieces (commu-
tator) screwed to the shaft or axis,
from there the current goes through
pieces of sheet copper sliding on the
commutator, to the outside line.
The outside line consists of copper
wire of about 1900 in. diameter, and
heavily weather-proof insulated by
means of double hemp braiding,
saturated with white lead.
The wire is fastened on glasses to
the poles to prevent the escaping of
any electricity to the ground.
The light used in McMinnvile is
called arc light. The current going
through the mechanism of the lamp,
passes through to carbons of about ~
inches in length and ( inch dame
ter, which touch each other before the
light is produced, but are separated
about 4 inch after the current is turn
cd on, causing continuous spark
over the space, thus producing a most
powerful light. This sparkling re-
peats in such rapid succession, about
1000 times minute, that it is impos.
sible for the human eye to perceive
the vibrations, and it appears as a
perfectly steady light.
The carbons are by this burning re-
duced in length, and last about
hours, when new pair has to be in
serted. Through the action of thu
mechanism of the lamps the proper
space of / inch is always maintained
The street lamps are provided will
two pairs of carbons. The seconC
pair is set automatically in action a
soon as the first pair is consumed
These lamps burn Is hours continu
ously.
Each of the lamps is provided
with switch, by which the light cal
be started or put out. / would ad
wise the use of a wooden stick (broon
stick to turn this switch on and of
1t is not dangerous for one who un
derstands electricity to close the cir
cult by hand, but it might be possible
to experience shock, which Nigh
prove very disagleeable, especially i
there should be anything wrong will
the line.
The line is so constructed that NJ
current escapes to the earth, but b,
the very high pressure that is neces
sary to drive the current through tn
many lamps and long distance, i
sometimes occurs that after sever
rains some of it escapes over the glas
insulators. BY touching the wire q
that time, the person forms a conneC
ton through his body, consequent
gets shock. Therefore let the wire
alone if you have no business to har
die them.
The store lights have always to b
turned Off before leaving, otherwis
they would burn all night, which wi
injure the lamps when the carbon
are burned down.
The dynamo is automatic; that il
it regulates itself, and gives always
steady current. The lamps, there
fore, can be turned off or on, withou
affecting each other.
The system used here is the Thon
son-Houston arc light. 1t is not e2
celled by any other, and more tina
two-tnirds of all the arc lights in tn
United States are manufactured b
this company.
Hoping ! have embodied in tn
little communication all the princip
points of interest pertaining to ii
plant, l will be very glad to answt
oil questions that should arise, as
have cheerfully done up to this ola.
Yours truly,
MAX CAsPARI,
Electrical Engineer and Expert
Thomson-H Houston Co.