which is effected by their adoption, and to the ease with which they are
worked.

The success of the Decauville railway has been so rapid and so great
that many inventors have entered the same field, but they have almost
all formed the idea of constructing the portable track with detachable
sleepers. There are thus, at present, two systems of portable tracks:
those in which the sleepers are capable of being detached, and those in
which they are not so capable.

The portable track of the Decauville system is not capable of so coming
apart. The steel rails and sleepers are riveted together, and form only
one piece. The chief advantage of these railways is their great
firmness; besides this, since the line has only to be laid on the
surface just as it stands, there are not those costs of maintenance
which become unavoidable with lines of which the sleepers are fixed by
means of bolts, clamps, or other adjuncts, only too liable to be lost.
Moreover, tracks which are not capable of separation are lighter and
therefore more portable than those in which the sleepers are detachable.

With regard to sleepers, a distinction must be drawn between those which
project beyond the rails and those which do not so project. M.
Decauville has adopted the latter system, because it offers sufficient
strength, while the lines are lighter and less cumbersome. Where at
first he used flat iron sleepers, he now fits his lines with dished
steel sleepers, in accordance with Figs. 1 and 2.

[Illustration: Fig. 1. Fig. 2.]

This sleeper presents very great stiffness, at the same time preserving