(3) It tends to prevent strife and litigation. (4) To provide for the safety of those working in coal mines by sufficient pillars of support. Under this head see the many provisions in the coal mine law (Appendix to Code, p. 991 et seq). This is no undue assumption of the right to apply the police power to a subject which does not fall within it, for regulations on all these subjects have long been recognized as wholesome and reasonable, and as fit subjects for the exercise of the police power, as tending to preserve the rights of the citizen and to promote the welfare of the commonwealth. The mining of coal is one of the largest industries carried on in the state. In mining, proper support and ventilation are necessary, and an ample supply of fresh air is stringently exacted by our law on the subject. See coal mine law (Code, pp. 994, 995, §§ 9-11). This is necessary for the health and safety of the miner engaged in a dangerous employment, and for that reason the public welfare requires it: but no proper system of ventilation can be maintained by any mine owner unless the area to be worked by him is isolated or bounded by a zone or rib of coal thick enough to support the roof, and to be thick enough to prevent the escape of the air, with no passways down through his dividing line which may prevent the due circulation of the air, and render due ventilation very difficult. The same may be said of keeping his mine properly drained as required by law, and impervious to water from adjoining mines and lands. The act of 1834 fixed this bounding zone between adjoining land owners at 50 feet, the present act at 10 feet. Thus we see that this rib of solid coal not to be mined into by either of the adjoining owners was to be contributed by each in equal parts, was for the mutual benefit of each, for the protection of the surface, to secure independent systems of ventilation, drainage and workings, and in aid of an industry so great and widely diffused that the state as a whole is interested therein. Besides, the importance of having these unbroken ribs of support throughout the mining region is being realized as a state affair more and more as the mining of coal goes on. This regulation works no hardship on one for the benefit of the other, but is impartial, just, and reasonable, imposing a common burden for the benefit of all such owners. This regulation, in substance, has been in force for more than

CO years without complaint. This is a high degree of evidence that it is not an unconstitutional exercise of police power to require this natural boundary wall to be preserved intact. See 15 Am. & Eng. Enc. Law, 593 et seq.; Cooley, Const. Lim. (3d Ed.), top page 578."

Sec. 548. Mining partnerships. In order to constitute a mining partnership under Mont. Civ. Code, 1895, §§ 3350-3359, two or more persons shall acquire a mining claim for the purpose of working it, and extracting the minerals therefrom, and such owners must actually engage in working the mine. A partnership does not exist where one part owner of a claim is working a disputed portion thereof alone, excluding other part owners therefrom. Anaconda Copper Min. Co. v. Butte & B. Min. Co., 17 Mont. 519 (43 Pac. Rep. 924). For construction of particular contract held to create a mining partnership, see Ashenfelter v. Williams,

Colo. App. (43 Pac. Rep. 664). A mining partnership is not founded upon the delectus persona and neither assignment, death nor bankruptcy of the owner of an interest in a mining concern will operate to dissolve a mining partnership. Patrick v. Weston, 22 Colo. 45 (43 Pac. Rep. 446), citing, Colorado cases. When a mining partner reaps the benefit of an act done over his protest by his co-partners he will be liable to his co-partners for his share of the expenses. Patrick v. Weston, 22 Colo. 45 (43 Pac. Rep. 446).

Sec. 549. Mining leases. Where an assignment for creditors is made by a lessee of a mining lease which provides that upon the termination thereof the lessor may take the improvements at their appraised value and a cause for forfeiture of such lease exists prior to the assignment, which is enforced by the lessor subsequently, he is entitled to take the improvements at their appraised value, in satisfaction of rent due. Potter v. Gilbert, 177 Pa. St. 159 (35 Atl. Rep. 597; 35 L. R. A. 580). A mining lease is so far in the nature of a sale of the minerals that when executed by life tenants and remaindermen the former are only entitled to the income arising from the royalties, the corpus thereof passing to the remaindermen upon the termination of the life estates. Blak

ley v. Marshall, 174 Pa. 425 (34 Atl. Rep. 564). An assignee of a mining lease takes it subject to all its stipulations, Woodland Oil Co. v. Crawford, 55 O. St. 161 (44 N. E. Rep. 1093; 34 L. R. A. 62); but he acquires only the rights of the lessee and cannot enforce against him his covenant with the original lessor not to divide "his time or attention with any other mine," Findlay v. Carson, 97 Ia. 537 (66 N. W. Rep. 759). A lease of land" for the purpose of exploring for, mining, taking out, and removing therefrom the mercantile iron ore which is or which hereafter may be found on, in, or under said land," at a specified annual rent, presupposes the existence of ore, and if, after reasonble efforts on the part of the lessee, no ore is found, the lease fails, and no rent can be collected. Blake v. Lobb's Estate, 110 Mich. 608 (68 N. W. Rep. 427), following the case of Gribben v. Atkinson, 64 Mich. 651 (31 N. W. Rep. 570). Where a lessee of a coal mining lease, without prosecuting the mining operations provided for in his lease, pays the annual royalty stipulated in order to prevent a forfeiture he cannot recover the moneys so paid upon subsequent operations revealing the fact that no coal could be mined from the land. Bloomfield Coal & Mining Co. v. Tidrick, 99 Ia. 83 (68 N. W. Rep. 570). For construction of particular mining leases as to the matter of royalties, see Schooley v. Butler Mine Co., 175 Pa. St. 261 (34 Atl. Rep. 639); Boyer v. Fulmer, 176 Pa. St. 282 (35 Atl. Rep. 235); Shoemaker v. Mt. Lookout Coal Co., 177 Pa. St. 405 (35 Atl. Rep. 731); Lehigh & Wilkesbarre Coal Co. v. Wright, 177 Pa. St. 387 (35 Atl. Rep. 919). For construction of particular oil and gas lease, see Williams v. Guffey, 178 Pa. St. 342 (35 Atl. Rep. 875).

Sec. 550. Oil and gas lease-Power of court of equity to compel operations under-Construction. It is held by a divided court that where one leases land for oil and gas adjoining other lands which he is working for oil and gas and it becomes apparent that his operations on the latter will drain the leased lands of their oil and gas, a court of equity may, under penalty of forfeiture of the lease, require the lessee to open such wells on the leased lands as are necessary to secure the full product of oil and gas belonging thereto and

prevent their loss by drainage. Kleppner v. Lemon, 176 Pa. St. 502 (35 Atl. Rep. 109). The court say: "It is an implied condition of every lease of land for the production of oil therefrom that, when the existence of oil in paying quantities is made apparent, the lessee shall put down so many wells as may be reasonably necessary to secure the oil, for the common advantage of both lessor and lessee. In determining when and where such wells shall be located, regard must be had to the operations on adjoining lands, and to the wellknown fact that a well will drain a territory of much larger extent when the sand rock in which the oil or gas is found is of coarse and loose texture than when it is of fine grain and compact character. Whatever ordinary knowledge and care would dictate as the proper thing to be done for the interest of both lessor and lessee, under any given circumstances, is that which the law requires to be done as an implied stipulation of the contract. If this was not so held, it would be practicable to defeat the very purposes of the contract, and to drain from the land of the lessor the oil underlying it, and yield him nothing in return." Where an oil and gas lease stipulates for the payment of a specified yearly rental "for every well from which gas is used off the premises," the liability of the lessee for rent terminates upon his ceasing to use the gas. Indianapolis Gas Co. v. Teters, 15 Ind. App. 475 (44 N. E. Rep. 549). Construction of particular oil and gas lease as to the right of lessee to terminate. Double v. Union Heat & Light Co., 172 Pa. 388 (33 Atl. Rep. 694).

Sec. 551. Oil and gas lease-Construction of stipulations as to default. C. granted, demised, and let, by written instrument, a certain tract of land and all the oil and gas in or under the same to U. and his assigns, for the purpose and with the exclusive right, of drilling and operating the land for gas and oil for five years, and as much longer as oil or gas should be found thereon in paying quanties, upon the consideration of one dollar paid, and a promise to pay certain rentals for further delay if default should be made in drilling a well within one year, and which instrument had the following forfeiture clause: "And a failure on the part of U. to complete such well or wells as above specified, or instead

thereof to pay the rental as above provided, shall render this lease and agreement null and void, together with all rights and claims, and not binding on either party, and not to be revived without the consent of both parties hereto in writing." Default having been made in drilling, in an action to recover the promised rental, held: First, that such instrument is a lease of the land, oil and gas for the limited time and purpose expressed therein. Second, that the forfeiture is for the benefit of the lessor, and at his option. Third, that the promise to drill a well or pay rental cannot be discharged by a mere failure to perform the promise. Fourth, upon failure to drill the well, or instead thereof to pay the agreed rental, such rental may be recovered by action, as rental, and need not be sued for as unliquidated damages. Woodland Oil Co. v. Crawford, 55 O. St. 161 (44 N. E. Rep. 1093; 34 L. R. A. 62). The court say: "A promise to pay cannot be fulfilled by a failure to pay. A promise to drill a well cannot be satisfied by a failure to drill such well. The proper construction to be placed upon such an agreement is that, upon failure of the lessee to drill a well, or pay the rental, or both, as the case may be, the lessor may elect to put an end to the lease, and enforce payment of the promised rental, or sue for damages for failure to drill the well; or he may elect to have the lease continue in force to the end of the term, and enforce the drilling of wells and the payment of rentals as provided in the lease. Such provisions of forfeiture are for the benefit of the lessor, and not for the benefit of the lessee. The lessee cannot plead his own default or wrong in discharge of his obligation to drill or pay rental. Parties may agree that, in case of failure to drill, or failure to pay, or both, the lessee shall be relieved of his obligation upon such terms as the parties may agree upon in the lease, whether the terms be of value to the lessor or loss or inconvenience to the lessee; but a naked default or non-performance, as in this lease, cannot be held to discharge the obligations of the lessee. The following authorities are in point: Leatherman v. Oliver, 151 Pa. St. 646 (25 Atl. Rep. 309); Ray v. Gas Co., 138 Pa. St. 576 (20 Atl. Rep.1065); Clark v. Jones, 1 Denio 516; Galey v. Kellerman, 123 Pa. St. 491 (16 Atl. Rep. 474); Jones v. Gas Co., 146 Pa. St. 204 (23 Atl. Rep. 386); Wills v. Gas Co.,