Fort Worth gazette. [volume] (Fort Worth, Tex.) 1891-1898, 1895-11-29

rating pant over u IOtu tMehtss hA''
a hundred miles long. Until recently
II has been customary, where cars were
TO be run on a route extending more
than very few miles, to establish
another station. and get up othei
dynamos to furnish the necessary cur
rent. At the present time all electric
cars are operated by what Is called the
direct or continuous current. some
day, perhaps, we snail see alternating
current motors under electrically pro-
PEELED cars, but they have not yet come
into se.Ige. A direct current must De
sent at the voltage at wnich II is 10 oe
used. The volume of electricity sent,
II Will be remembered, Is measured oy
ampefes, and the pressure at which IL
is sent By volts. The two must always
be kept distinct In the mind. altroush
they are sometimes convertible one mo
the other by means OF an apparatus
called a transformer. The usual volt
age Is 800 on railway motors. But the
line resistance In such a case Is 30
great that after the first four or nve
miles the drop" or exhaustion OF the
current, is wasteful. This difficulty
puts u limit on the distance from the
power house at which trolley road
may be advantageously operated. IL
the voltage were increased. copper
conductor Of the size now in vogue
would carry the current further. but,
unfortunately, 1t does not Seem to be
practicable to raise the voltage above
that at present employed. Again. III
larger feeders were used to conduct
the current, the same object would be
attained, but the cost OF copper puts
that resource out of the question.
Still another solution of the problem
was thought OF two or three years ago,
and some recent experiments have
demonstrated Its practicabillty so fully
us to command wide attention among
people interested in electric traction.
The principle utilized may be stated In
a very few words. The alternating
current Is peculiarly suited to long
distance transmission, because IL may
be easily transformed to very high
voltage, and thus sent over a score. "
not q hundred miles, economically; and
at its destination II can be as readily
transformed down again to whatever
voltage IL desired. II may also be
made to undergo another change. 1t
can be turned Into direct current.
This, then, is precisely what has lately
on which the system has been tried
are not very much LONGER than those
whose feeders carry direct current, II
Is easy to see that the plan Is suscepti-
BILE OF extension over much greater dis
tunces. The chief thing demonstrated
so far IL that the idea Is feasible.
Before describing the principal road
on which the new method has been
tried a brief alluslon may be made to
attn another effort to evade the ditli-
Guilty referred to. In Norwich, Conn,
an alternating current Is brought from
Il distance to tho Ponemah mills for
manufacturing purposes. Enough cleo
trlclty is taken from the supply 10 run
the street cars OF Norwich. But the
Ia tot
n direct current In the manner Just In
dlcated. Instead, 81 is used 10 run a
stationary alternating current motor
which IL connected, Just as steam en-
CINE might be, with direct-currcnt
dynamo. The latter generates the cleo
trlclty used by the street railway. a
similar thing Is d ne In sacramento,
whittier several thousand horse power
Is being transmitted from Folsom
twenty-four miles away, at voltage
OF 10000. Now instead Of coupling two
separate machines together, the latest
plan employs a single machine, n "ro-
tary converter" which. after the volt
age is reduced by "static transforms
ers," changes the alternating current
into n direct one.
The pioneer venture with this system
was made on line between Lowell,
Mass. and Nashua, N. H., hfteen miles
away. The current is generated in the
former city by three four-pole. 100 lSilo-
watt dynnmos, and Issues at a voltage
Of $50. The thrce-phaso type OF alter
mating current Is employed, That Is
TO say. instead OF only one there are
three separate currents, having the
same number OF alterations second
but one having Its wave crests coming
n short distance behind those Of nnoth-
or. THIS Is not an essential feature OF
the present scheme, but was doubtless
adopted to permit the use Of three
phase motors Zone OF Tesln's great in
ventlons) at some future time If de-
sirAble The current developed at
Lowell Is carried to n bank Of trans
formers and raised to $500 volts, In
sulatcd cables on poles take the current
to the city limits. from which point II
travcrses the bare wires OF an ordt-
nary three-phase system. At Eayus
mills six miles ont, and also at Nashua
there are sub-statlons, provided
with step-down transformers. that re-
duce the voltnEe to 800 again. md ro-
tnry converters which make the fur
Their mobilization desired. This appa-
ratus, designed and made by the Gem
tral Electric comnany, is of the most
modern nnd improved style. and pos
scsscs many features OF great technical
excellence that need not pe mentioned
here. The direct current empnating
from the converters is led out into the
feeders Of n railway, over which there
run cars much larger than those usu-
ally seen on trolley roads. and more
closely resembling the open excursion
cars In service on many steam lines.
These vehicles do not come into Lowell
but stop at a point between that city
and Easyus' mills. called Lake View,
which IL the terminus OF the previously
existing trolley line in Lowell. The
two roads are operated In connection
and under one MANAGEMENT