101 A.2d 649 Herod, Appellant, v. Luxner. Supreme Court of Pennsylvania.October 1, 1953. January 4, 1954. Contracts — Leases — Construction — Strip-mining of coal — Minimum royalties — Impracticability — Rock formation. 1. Where a written lease for strip-mining a certain vein of coal for a fixed term of 18 months obligated the lessee […]