The Wilmington daily Republican. (Wilmington, Del.) 1890-1902, 1897-01-18
s.sI AN ELECTRICAL WONDER. -
Ineidents bf trolley Ride Through tbe
Largo Sswefs Of Paris.

The main sewers Of Paris are periodical
ly cleared BY ineSns Of sorapers carried on
boats or cars These conveyances are also
used for conveying visitors through the
large sewers under the Rue de Rivoli and
the Boulevards Sevastopol and Des Males.
herbes These exhibitions take place four
times year, In spring and autuQn, and
about s,4o0 visitors are admitteS yearly.
Until 1894 these cars and boats were drawn
by men, but the labor and expense were
found to be SO excessive that now the trac-
ton Is done entirely by electric motors,
taking current from eccumulator batteries
on the boats OR cars. These main sewers
are In section very similar to an ordinary
tunnel; but In the aoor Is formed the rec.
tangular channsl for the sewage, while
round the rosf are fixed the water and
compressed air mains, the telegraph and
telephone wires, otc. The sewer under the
Boulevard DIES Maiesheroes is the largest,
1t Is IS feat a inches wide, 10 feet high
from floor to roof, and the sewage channel
In the floor is 8 feet u inches deep and 8
feet 10 inches wide Boats are used in this
channel
nels in them being only feet II inches
wide and from 8 feet II inches to feet
inches deep. In these, cars are run, the
Hanged wheels of tho cars running on tho
edges of the channel, which are protected
by angle bars, and from the rails. The ap,
proximate weight of train Of ave cars
with 100 passengers on board is about
tons IL hundredweight, and this travels at
the rate of ~ miles per hour. The accu
mulator battery Consists of 2S elements
and weighs IA hundredweight, and its Ca
pactty is 100 ampere hours, with a mean
discharge of rs amperes at so or 60 volts.
The motor, which is series wound, develops
Q horsepower and runs at / 600 revolu-
lions per minute, this speed being reduced
to so by means Of pinion and wheel and
chain gearing to the driving axle, the
wheels being 15s4 inches in diameter Oh
the tread
The boats are lowed by means Of chain
sunk In the sewage channel, which Is
brought to the surface and passes round
pulley driven by means of a double reduc-
ton gear from the motor. The chain, by
means of guide pulleys, makes three quar-
tiers of turn round the driving pulley,
this pulley being a magnetic one, magnet.
lied by means Of two coils, one on each
side of 1t, on the axle Each passenger
train consists of six boats, in the first OF
which are carried the accumulation battery
and towing apparatus, while in the last
boat, which is a smaller one, there Is an
other towing apparatus.
The battery consists Of 60 elements, Civ |
ing an output of go amperes for az hours
at from 9S to 1875 volts. 1t is divided into |
two parts, which can be connected in series
or parallel, as required. The motors run |
at $50 revolutions per minute but this |
speed is reduced by means of the gearing 80 !
that the boats travel at about u miles per
hour. The power required for this Is from
about 2 horsepower to 81 horsepower, ac-
cording as the boats are travelling with or
against the current The total length of |
the sewers open in this way to the public
Is about two miles, and they are lighted
partly by lamps on the footpaths or by oil
lamps on the boats Genie Civil.