3. The freight train couples on to the "last half" of the passenger train, goes down, then pushes up on the switch, and leaves it.
4. The freight train backs off the switch, and then goes ahead about its business.
5. The "first half" of the passenger train backs upon the switch and gets the "last half" of itself, and goes on about its business.
[For exchanges, see third page of cover.]
Fig. 1.