Opinion by
Mr. Justice Williams,The learned counsel for the appellant states the point in controversy very fairly and clearly in the opening sentence of his printed argument. He says : “ The contention in this case is confined to the effect and subsequent history of the Callender lease, dated the first of October, 1828.” His position is that the lease granted only an incorporeal right to the lessee, to be exercised upon the premises covered by the lease. The appellees, on the other hand, contend that it granted the coal in place, under the land, absolutely. The words of the instrument upon which this question depends may be put together thus : “ Samuel Callender .... doth lease and to farm let to Thomas Meredith .... all the land that he now holds .... and the leas? is to continue for the term of one hundred years from this day. Possession of the leased premises shall extend only to their use as a coal field. The lessee shall have full power and possession to search for coal anywhere on the leased premises, in any manner he may think proper, to raise the coal, when found, from the beds ; to enter and carry away coal; and to sell the same for his own benefit and profit. He may occupy whatever land may be useful or necessary as coal yards .... for roads for transporting the coal; and in case it may prove necessary for securing the full enjoyment of the premises aforesaid as a coal field as aforesaid, then the said Samuel covenants and agrees to execute such further writings as counsel learned in the law may deem proper.” The purchase money or price of the coal is fixed at two hundred dollars. If the coal proved abundant and of a given thickness then another hundred dollars was to be paid. In addition to this the sum of one dollar per annum was to be paid as rent. The lessor reserved out of this grant the right for himself and his heirs to take coal for their own use so long as they should reside on the land.
*492This instrument contemplates a sale of the coal Tinder the leased premises at a fixed price, to be increased one hundred dollars if the quantity of coal reached the proportions described in it. The right of removal was to be exercised within one hundred years. The fact that the instrument is in the form of a lease is not material when the character of the transaction is apparent: Kingsley et al. v. Hillside Coal & Iron Company, 144 Pa. 613; Montooth v. Gamble, 123 Pa. 240. A written contract, though not under seal, granting the privilege of digging all the coal or ore on the vendor’s land, is equivalent to a conveyance of the title to the coal or ore in fee : Fairchild v. Furnace Company, 128 Pa. 485. Such a conveyance operates to sever the surface from the underlying stratum of coal; and after such severance the continued occupancy of the surface by the vendor is not hostile to the title of the owner of the underlying estate, and will not give title under the statute of limitations. To affect the title of the owner of the coal there must be an entry upon his estate, and an adverse possession of it: Armstrong v. Caldwell, 53 Pa. 284.
But the contention that a right to mine coal in the land of another is an incorporeal ■ one cannot be successfully maintained. The grant of such a right is a grant of an interest in land: Hope’s Appeal, 33 Pitts. L. J. 270. When the grant is in terms or in effect a grant of all the coal on the lessor’s land, this amounts to a severance of the coal from the surface, and vests a title to the underlying stratum in the grantee : Sanderson v. The City, 105 Pa. 469. This underlying estate may be conveyed under the same general rules as to notice, as to recording, and as to actual possession, as the surface. After such a severance, the possession of the holder of each estate is referable to his title. The owner of the surface can no more extend the effect of his possession of his own estate downward, than the owner of the coal stratum can extend his possession upward, so as to give him title to the surface under the statute of limitations. The owner of the surface can be affected only by the invasion of the surface. The owner of the underlying stratum is not bound to take notice of the invasion of the estates that do not belong to him ; but when his own estate is invaded he is bound to take notice. The conclusion thus reached disposes of the title by possession set up by the plaintiffs, and of their right to recover in this case.
*493The appellant cites the Venture Oil Company v. Fretts, 152 Pa. 451; McNish v. Stone, 152 Pa. 457, and other cases in which oil leases were considered and the rights of the lessors and lessees defined. A lease granting to the lessee the right to explore for oil and, in case oil is found in paying quantities on the leased premises, to drill wells and raise the oil, paying an agreed royalty therefor, has been held to convey no interest in the land beyond the right to enter and explore, unless the search for oil proves successful. If it proves unsuccessful and the lessee abandons its future prosecution, his rights under the lease are gone. So it might be with a similar lease of lands supposed to contain coal. If the lessee entered, explored the leased premises, and, finding nothing, gave up the search, he would no doubt be held to the same rules, upon the same provisions in the lease, as were applied in the cases cited. The difference in the nature of the two minerals, and the manner of their production, has however resulted in considerable differences in the forms of the contracts or leases made use of. When oil is discovered in any given region, the development of the region becomes immediately necessary. The fugitive character of oil and gas, and the fact that a single well may drain a considerable territory and bring to the surface oil that when in place in the sand-rock was under the lands of adjoining owners, makes it important for each landowner to test his own land as speedily as possible. Such leases generally require, for this reason, that operations should begin within a fixed number of days or months, and be prosecuted to a successful end or to abandonment. Coal on the other hand is fixed in location. The owner may mine when he pleases regardless of operations around him. Its amount and probable value can be calculated with a fair degree of business certainty. There is no necessity for haste, nor moving pari passu with adjoining owners. The consequence is that coal leases are for a certain fixed term, or for all the coal upon the land leased, as the case may be. The rule of Venture Oil Co. v. Fretts, supra, is not capable of application to the lease made by Callender to Meredith in 1828 for several reasons: (1) The Callender lease is in effect a sale of all the coal in the leased premises, and consequently a severance of the surface therefrom. (2) It is for one hundred years. All idea of haste in development or operating is excluded by the terms of tire instrument, *494and tbe time for commencing the work of mining is left to the discretion of the lessee. (3) The consideration of the grant was not the development of the mineral value of the land, but the price fixed by the agreement and actually paid to the lessor in money.
Upon a careful examination of the several assignments of error we are all of opinion that the judgment must be affirmed. Judgment will be entered accordingly.