.

[Footnote 1: Paths parallel with the public walks.]

In the first case (Fig. 1), the viaduct is wholly metallic, while
in the second it comprises masonry arches surmounted by a metallic
superstructure. The viaduct is formed of independent spans supported
by metallic piers that rest upon masonry foundations (Fig. 2).

[Illustration: FIG. 1.--PROJECT FOR A PARISIAN ELEVATED RAILWAY.]

[Illustration: FIG. 2.--LONGITUDINAL ELEVATION.]

The line will have three kinds of stations, intermediate, "tangent,"
and terminal ones. It is at the latter that the two superposed lines
are connected by the circular inclined plane.

The waiting platforms of the intermediate stations will be formed
simply by the widening of the span corresponding to the station.
Access to these platforms will be had by stairs running up from the
edge of the sidewalk. The passengers will make their exit by means of
corresponding stairs on the opposite side. (Figs 3 and 4.)

[Illustration: FIG. 3.--A STATION.]

[Illustration: FIG. 4.--TRANSVERSE SECTION OF STATION.]

The tangent stations are placed at the meeting point of two lines,
which, instead of crossing each other, are bent inward like an X, the
two parts of which will be tangent to the central point. Through
such arrangements the running of the trains will be continuous, and
a traveler reaching one of these stations will be able, upon changing
train, to take at his option any one of the three other directions.

As may be seen, Mr. Garnier's project presents conditions which
are very favorable to the establishment of an elevated road in the
interior of Paris. Far from injuring the aspect of the great arteries
of our metropolis, the viaduct, as it has been conceived, will
contribute toward giving them a still more imposing look. If the
beautiful is, as has been said, the expression of the useful, an
elevated railway, well conceived, may be beautiful. The project of
a subterranean railway is attended with great drawbacks, not only
as regards the great expense that it would necessitate, but also the
difficulties of constructing it. And there is a still graver objection
to it, and that is that it would oblige travelers to move like moles
in dark, cold, and moist tunnels. At Paris, where we are accustomed
to a pleasant climate and clear atmosphere, we like plenty of air and
broad daylight.--_La Nature._

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ENGINEERING INVENTIONS SINCE 1862.[1]