Select a point where two rails join, for a switch, and take one length
of rail for the purpose. This length, which includes both rails, of
course, is to be movable, and so must slide over the common ties, and
not be fastened to them. To keep them in place they must be tacked to
special ties, much thinner, and coming between the regular ties that
they slide over. Having prepared this length, put a tack, smaller than
the hole you have punched, through the end hole at _a_ (_fig. 4_), so
that the switch will move easily on it.
[Illustration: FIG. 2.]
At _b._ (_fig. 3._), where your two tracks come together, you must put
pegs (_b. b._) to keep the switch from moving too far either way, and
throwing your train off. Also, from this point, the ties must be long
enough to hold the side track till it is clear of the regular track
(_fig. 3_). The curve of this side track is made, of course, by the
directions for making a curve. The last special tie at _c_ (_fig. 3_)
must run out far enough to take a hold of, to move the switch.