The San Francisco call., 1896-12-25
AN ELECTRICAL WONDER.
Incidents of Trolley Ride Through
the Large Sewers of Paris.

Incidents of Trolley Ride Through
the Large Sewers of Paris.
The main sewers of Paris are periodi-
caily cleared by means of scrapers carried
on boats or cars. These conveyances are
also used for convey ing visitors through
the large sewers under the Rue de Rivoli
and the Boulevards Sebastopol Des Males
herbes These exhibitions take place four
times year, in spring and autumn, and
about s400 visitors are admitted 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
traction is done entirely by electric mo-
tors, taking current from accumulation
batteries on the boats or cars. These
main sewers are in section very similar to
an ordinary tunnel; but in the floor is
formed the rectangular channel for the
sewage, while round the roof are fixed the
water and compressed air main, the tele-
graph and telephone wires, etc.
The sewer under the Boulevarde des
MaIesherbes is the largest. 1t is Is feet Az
inches wide, 10 feet high from floor to roof
and the sewage channel in the floor Is 3
feet 5L inches deep and feet 10 inches
wide. Boats are used in this channel.
The other sewers are smaller, the channels
in them being only feet IL inches wide
and from feet IL inches to 5 feet inches
deep. In these cars are run, the 6anged
wheels of the cars running on the edges of
the channel, which are protected by angle
bars, and from the rails. The approx
mate weight of train of five cars with
100 passengers on board is about ZOO
pounds, and this travels at the rate oil 33z
miles per hour.
The accumulate battery consists OF %
elements, and weighs IA hundredweight,
with mean discharge of 25 amperes at
90 or 60 volts TIE motor which is series
wound, develops 2 horsepower and runs
at 1900 revolutions rer minute, this speed
being reduced to so by means of pinion
and wheel and chain gearing to the driv-
ing axle. the wheels being 15A inches in
diamet r on the tread. The boats are
towed by means of a chain sunk in the
sewage channel, which is brought to the
surface and passes round puIly driven
by means of double reduction gear from
the motor. The chain, by means OF guide
pulleys makes three-q quarters of turn
round the driving puily, this pully being
a magnetic one, magEetiZed by means of
two coils, one on each side of it, on the
axle.
Each passenger train consists of six
boats, in the first OF which are carried the
accumulator battery and towing appa-
| ratus, while in the last boat, which is a
smaller one, there Is another towing ap-
paratus. The battery consists of go eie-
ments, giving an output of so amp eres for
2X hours, at from SO to 125 volts; it is
divided into two parts, which can be con-
nected in series or parallel as required.
The motors run at $50 revolutions per
m mute; but this speed is reduced by
means of the gearing, so that the boats
travel at about ~ miles per hour. The
power required Tor this is from about 2
horsepower to 81 horsepower, according
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