St. Paul daily globe., 1890-01-19

- HAT within the last few
. / ]. / . !. |. : ]
II. years there has been an
y Il r. immense increase in the
E q humber of industries to
& q Al which electricity is ap-
81 "A - llied is trite remark.
BI - lut few have given any
FL - lose attention to any but
@ y the most obvious and
Il - common changes that
u F. have taken place in the
~ uses to which the cleo
trical current has been
put, anu still fewer have any adequate
ldea OF the extent to which it is used in
even the most familiar methods.
FIFTEEN OR EVEN TEN
years ago it may be broadly stated that
electricity, save in the telegraph, ard to
very small degree in medicine, was
Industrially unknown. To-day, although
electrical science is admittedly in its in
Ianey, the change has been so great
that were electricity to be confined
to the uses to which it was put
prior to the last decade, the incOn-
venlence would be more intolerable
than those that would have resulted had
the world been deprived of the tele-
graph during the period just after the
Wdr.
Had any one in 1870 been informed
that in less than twenty years private
conversation could be carried on be-
tween persons separated by more than
$50 miles, an application de lunatlcO i'll
qulrend0 would probably have been
made, and would more than probably
nave succeeded. But at the present
time man in New York can talk to
one in Boston, the varying tones of the
voice being distinctly recognizable
The dim and insufficient gas lamps have
for street lighting been very generally
replaced by the arc lights. The pres
SureS in use vary from 500 to 2,500 volts,
the average length of circuits in central
lighting stations being about four miles.
Jhere are Instances on record where
circuit of niue miles has been supplied
from single central station.
THERE ARE NOW IN OPERATION
In this country $50 central station arc
and lncandeScent plants, and 500 iso-
lated arc plants in factories, mills and
other buildings. The systems most
generally employed are the Edison three
wire system and the Thomson, West
inghOuse, Brush and Slattery alternat-
ing systems.
AS the difference between these sys-
TENS is not very we'll understood,
short explanation may not be out of
place. In the alternating systems
pressure of from 1000 to 1000 volts. not
infreQuently more, is maintained upon
primary circuit, which is very small.
TDiS circuit is carried into the base
ment of the building to be lighted,
where it is connected with a converter
or tranSmitter, which consists of two
coils of wire so placed and proportlOned
as to reduce the pressure OF 1,O00 volts
on the primary circuit to fifty volts on
the secondary or lamp circuit. Two
wires are used in this system. the con-
Verters being in multiple arc.
In the Edison low-tension system of
central station lighting three wires are
used throughout, with q pressure be-
tween the inner and either outside wire
OF ITO volts. or maximum pressure of
220 volts, The current is direct, and a
constant pressure maintained through
out, indicators and regulating instru-
ments being used to maintain the pres
sure at its proper intensity at all times.
There are in continuous operation in
this country 2,400 isolated incandescent
plants and there are manufactured for
their use 7,500,000 lamps annually.
AS A MEANS OF TRANSPORTATION
the development of electricity has been
the United States $50 different electric
street railroads. and the number is
monthly increasing. Steam is being
replaced by electricity in elevators.
Hundreds of printing Offices. thousands
of sewing machines, drills, fans, Iathes.
and a hundred other appliances de-
pend upon the new motor. The trans
mission of power over large distances is
now for the first time possible, With a
current of 1,0O0 volts 100 horse power
can be transmitted to the distance of
mile with loss of 10 per cent. Water
falls have been used as a source of
power for cities miles away by the in
tervention of the electric wire. In
mining it has revolutionized several de-
partments, while in surgery the sur.
geon's knife is guided by the incandes-
cent lamp, and the probe has in many
eases given way to the electric balance.
Electricity has been successfully en-
ployed in tanning hides, plating by the
electro deposition of copper and Silver
is daily becoming more popular, not a
few hOrSe-owners groom their stock by
electric power, packages can be rapidly
sent long distances, and the electric
current has been employed to replace
RI,r,l I, III IL .1-