In mining leases the lessee commonly agrees to pay a royalty varying with the amount of ore mined and also agrees to mine annually at least a certain quantity. It is a question of construction whether such a lease is made on the assumption by both parties that ore exists in such quality that it is commercially possible to extract the agreed amount; or whether the lessee takes the risk of this and binds himself to perform in any event.28 If the lessee's agreement is in terms rather to pay a minimum sum than to mine a minimum quantity, it is natural to infer that he agreed to take the risk of the existence of the ore, but if the agreement in terms is to mine a certain quantity, the surrounding circumstances may indicate that in making the agreement, the parties assumed the existence of the ore as a matter of course, rather than imposed the risk of possibility on the lessee; and in case of doubt the modern tendency seems rather to favor this construction.29

26 Clare v;. Lamb, L. R. 10 C. P. 334.

27 Hitchcock v. Giddings, 4 Price, 135. This decision is distinguished on this ground in Clare v. Lamb, L. R. 10 C. P. 334.

28 Cases of the latter sort are: Bute v. Thompson, 13 M. & W. 487; Lehigh Zinc Co. v. Bamford, 150 U. S. 605, 37 L. Ed. 1215; McDowell v. Hendrix, 67 Ind. 513; Valley City Milling Co. v. Prange, 123 Mich. 211, 81 N. W. 1074; Wharton v. Stoutenburgh, 46 N. J. L. 151; Timlin v. Brown, 158 Pa. 606, 28 Atl. 236; Corona Coal & Coke Co. v. Dickinson, 261 Pa. 589, 104 Atl. 741. Cf. Monnett v. Potts, 10 Ind. App. 191, 37 N. E. 729. Cases of the former sort are: Clifford v. Watts, L. R. 5 C. P. 577; Ridgely v. Conewago Iron Co., 53 Fed.

988; Brooks v. Cook, 135 Ala. 219, 34 So. 960; Mineral Park Land Co. v. Howard, 172 Cal. 289, 156 Pac. 458, L. R. A. 1916, F. 1; Fritsler v. Robinson, 70 la. 500, 31 N. W. 61; Gribben v. Atkinson, 64 Mich. 651, 31 N. W. 570; Blake v. Lobb's Estate, 110 Mich. 608, 68 N. W. 427; Hewitt Iron Min. Co. c. Dessau Co., 129 Mich. 590, 89 N. W. 365; Diamond Iron Min. Co. v. Buckeye Iron Min. Co., 70 Minn. 500, 73 N. W. 507; Buchanan v. Layne, 95 Mo. App. 148, 68 S. W. 952; Cook v. Andrews, 36 Ohio St. 174; Brick Co. v. Pond, 38 Ohio St. 65; Muhlenberg v. Henning, 116 Pa. 138, 9 Atl. 144; Boyer v. Fulmer, 176 Pa. 282, 35 Ail. 235; Bannan v. Graeff, 186 Pa. 648, 40 Atl. 805; Virginia Iron etc. Co. v.