As the ability of the town to build and maintain the highway was a material part of the question of laying out (Dudley v. Cilley, 5 N.H. 558,560, 561; Winship v. Enfield, 42 N.H. 197, 204, 205), a diminution of that ability is a change of circumstances that may be a sufficient reason for discontinuance. It is possible that after a road is laid out, and before it is built, the resources of the town may be so reduced that the expense of the road would be unreasonably burdensome.