The record-union., 1895-04-20
PARIS UNDERGROUND
Great Piece of Engineering Under IL
City Completed.

City Completed.
The extension underneath and into
| Paris of the Paris, Sceaux and Orsay
Railway, which William Barclay Par
sons, engineer to the Rapid Transit Com
missioners of the city of New York,
called the most important piece of under
ground construction in Europe, is de-
scribed in q recent issue of LOHdO1l ERgj-
ReeTillg with more of detail than in the
engineers report. The line is but 6,240
feet long, while the road of which it is an
extension dates back almost to the begin
ming of French railway history.
This road was twenty-three and three
quarter miles long, was laid out over a
succession of sharp curves and steep
gradients, and had at it's two termini
loops stations where trains could be run
through continuously, and passengers for
the return journey taken up without
shifting the engine or breaking the train
in any way. The line was originally
built with gauge OF feet 1O5 inches, but
this was afterWard reduced to feet 81
inches.
The original rolling stock, now obso-
lete was marked by some ingenious Pc
culiarities, among which was the con-
Meeting of all the axles in the train by
kind Of lazy tOngs arrangement Of crossed
rods so as To enable all the axles to auto
matlCally assume q radial position upon
| curves. This was on something like the
! principle which enables the siX-wheeled
| Robinson truck electric cars to take sharp
! curves so easily. All the railways Of
! Paris come within the ramparts and ap-
! proach the center of the city, stopping at
! various distances short of the center
! however. The SceauX Railway had its
| terminal most remote from the heart Of
! the city, and it was desired to extend II.
| The construction of the new line was
necessary below the street level. 1t is
not even approximately direct, as the
! authorities imposed onerous restrictions
| under the preteXt of saving the public
! from inconvenience during the progress
of the work and preserving the streets.
In one of the streets under which the
| railway runs was one of the most import
ant tramways OF Paris, and the operation
| OF this line could not be intertered with
| during the construction. In another
street, where traffic could not be inter
| tered with, the railway construction By
! driving tunnels was out Of the question
| on account of the nature OF the ground
| A network of mains and sewers beneath
| the surface added to the part of the diff
! Guilty, and in addition this whole of this
! section of Paris OverlieS vast system of
! catacombs, the arched roofs of which are
! apt TO fall in on very slight provocation.
! Two OF the stations are fortunately To-
Gated in open squares, which allowed of
working in open cuttings, which were
| afterward closed to form a covered way,
with the exception of such space as the
| company was permitted to leave open for
! ventilation. 1t was found necessary TO
consolidate the ground over the old cata-
! combs. The roofs of these excavations
| Law from thirty nine to seventy-two feet
beneath the rails, but they were subject
| to frequent failure, as proved by the sub
sidence of the surface and the wrecking
| of houses.
| At one point the line passes near a
! large observatory, and the men OF sci
ence protested against its construction,
alleging that with the passage of trains
| vibrations would be set up which would
! certainly affect the reading of the delicate
! instruments. 1t seems almost beyond be-
| lief to learn that at the time when the OBJ
| servatOry directors were protesting
against probable future disturbances
/ ballast trains were travelling continually
through the unfinished tunnel on a
! temporary track, without the knowledge
| of the observatory authorities or to the
detriment of the instruments. The tram