339. Covenants relating to pillars and barriers.

Under a covenant to leave, at the end of the lease, sufficient pillars for the support of the roof of the mine1 or the surface, or for the prevention of thrusts and creeps, the duty to leave pillars does not allow the pillars to be removed provided artificial support is substituted. In this respect the lessee's obligation differs from his obligation, if it exists, to support the surface, for in this latter case the lessee may work out the minerals affording support provided artificial support is substituted2.

A covenant to leave pillars for support will be enforced by injunction