Take a cold chisel, or an old common chisel, and one of your finished
rails. On the flat side (from _b_ to _c_, in _fig. 1_) cut slits
reaching from _b_ to _c_, and half an inch apart. Lay a row of ties in
the curve you wish to make, and bend the rail to fit them. The slits
will enable you to bend them nicely, on one side by gaping apart, and
on the other by slipping over.
If you want a guard rail to keep your train from running off at this
point, lay an extra rail fastened in the same way inside of each rail
on the curve.