The opinion of the court was delivered by
Porter, J.— This record starts a new question. Two men agree, in the most solemn form known to the law, one to demise certain premises, and the other to hold them, and pay rent. More closely considered, the instrument is a lease of land suitable for the breast of a dam, and the grant of an easement, namely, the right to overflow certain other land with water. In the body of the paper, it is expressly provided that the lessee, his heirs and assigns, may hold the said premises, liberties, and privileges, so long as he and they shall think proper, after the expiration of the term therein mentioned, on condition of paying rent. During the term, the lessee and his successors engaged in manufacturing enterprises unknown when the lease was signed, and for this nurpose they erected extensive improvements at large cost. After a century had elapsed, they were notified to quit, and sued in ejectment. The court below, notwithstanding the stipulation quoted, thought the plaintiff entitled to recover the land occupied by the dam-breast, and by the water of the dam west of a line defined in the charge. If the principle on which that opinion was founded be sound, it will fall with a heavy hand on the large manufacturing and mining interests of the country, in the conduct of which leases of this nature are extremely common, and we are bound to investigate it with care.
The ancient law was more favourable to this view than the modern. The earlier leases at will were all held at the will of the lessor. At a later period this modification was effected: “ When a lease is made to have and to hold at the will of the lessor, the law implieth it to be at the will of the lessee also, for it cannot be only at the will of the lessor, but it must be at the will of the lessee also. And so it is when a lease is made to have and to hold at the will of the lessee: this must be also at the will of the lessor; and so are all the books that seem, primé facie to differ, clearly reconciled:” Go. Lit. 55 a. In Lord Mansfield’s day, a lease for seven, fourteen, or twenty-one years, as the lessee might choose, was held good for only seven years: Bacon, Abr. *286title Leases, L. Afterwards a lease for three, six, or nine years was adjudged a lease for nine years, determinable at the intermediate periods by either party: Goodwright v. Richardson, 3 T. R. 463. It has since been settled that when a term of seven, fourteen, or twenty-one years has been appointed, and nothing said respecting its termination at the intermediate periods, the lessee only can determine it: Doe v. Dickson, 9 East 15; Dann v. Spurrier, 7 Vesey 231.
These decisions were pronounced in cases of ordinary letting, where the occupancy is an equivalent for the rent, and where, on the determination of the estate, the parties find themselves where they expected. The present is a different case. The lessee received from the hand of the lessor a clear and positive covenant of occupancy, first for a fixed term, and then for an uncertain one determinable only at the will of the former. Eor this covenant he paid full consideration in the rent punctually discharged for a century, and subsequently tendered on the trial of the cause. He went further, and furnished an overwhelming consideration in the detriment which must flow from the destruction of improvements erected with the lessor’s own knowledge and by his agreement ; for the water-power could have been purchased and employed for no other purpose. To permit the tenant’s expulsion from rights like these, without compensation, would violate all the analogies of the law; for while a tenant who expends money on the mere expectation of renewing his term, cannot thus arm himself with a right, Pilling v. Armitage, 12 Vesey 85; Watson v. The Hospital, 14 Vesey 333; it is equally true, that an owner will not be permitted fraudulently to encourage the occupier of an estate to lay out his money in improvements; Norway v. Rowe, 9 Vesey 159; Matts v. Hawkins, 5 Taunton 23; and the latter will even be protected in the possession of the estate for any term which he was thus encouraged to expect: Shine v. Gough, 1 Ball & Beatty 444.
In the case in hand, the lessee received, not encouragement, but express contract, for which he paid the price demanded, and more. We know of nothing in the law of Pennsylvania to prevent us from saying that he and his successors shall enjoy the benefit of this contract, and keep the land, so long as they pay the rent, or at the very least until compensation for the improvements thus made has been tendered. Two of our sister states have taken the lead in nearly this direction. The owner of a furnace sold it and leased the land on which it was erected, together with certain water privileges, to the purchaser, who covenanted to pay rent so long as he should keep the furnace on the land; and this was held to be a lease, terminable at the will of the lessee only: Cook v. Bisbee, 18 Pickering 527. A demise to A., his heirs and assigns, for such term or time as he shall pay rent, &c., and a covenant by *287him for himself and heirs to pay rent and perform covenants, constitute a perpetual lease: Folts v. Huntley, 7 Wend. 270.
On the principles thus indicated, justice will he administered, and the symmetry of the law preserved, by deciding that the facts of the case, as they stood at the trial, did not entitle the plaintiff to recover.
Judgment reversed and a venire facias de novo awarded.