delivered the opinion of the court.
*119
The first instruction given by the court was erroneous, for it assumes that a custom had been proven regulating the rights of miners, but the bill of exceptions is silent except as to the usage of a particular mine. The practice of a few persons in a business in which many are engaged will not establish a custom which all persons who are engaged in the same pursuit are presumed to know and recognize. A custom which would confer a right so important as that asserted in the instruction — being no less than the right of one person to occupy fo.r the purpose of mining the land of another as long as he pleases without a deed or other writing — ought at least to be well established by proof. A local custom must be proved on the trial; and we may suppose there was more evidence given on the trial of this case than we see in the record, but it ought to have been preserved in the bill of exceptions, so that it could be ascertained what interest the plaintiff had in the land.
The judgment will be reversed and the cause remanded to be retried ; and without intending to anticipate all the questions that may arise on another trial, it may be appropriate to notice some of them that will necessarily be presented. It will be developed by the evidence whether the plaintiff claims the right to mine on the defendant’s land as an easement or under a license. If he claims an easement it must be established by deed, for being an incorporeal hereditament it lies in grant and can not pass by livery. (Arnold v. Stevens, 24 Pick. 109.) A mere license may exist by parol, and ordinarily is not assignable, and is revocable unless it has been executed and the party has incurred expense on- the faith of it, so that he would be injured by its revocation. (3 Kent, 452; Pierpont v. Bernard, 2 Selden, 279; Wood v. Lead-*120bitter, 13 Mees. & Wels. 838.) In Cook v. Stearns, 11 Mass. 536, the court held that a license is technically an authority to do something on the land of another without passing an estate in the land, and a license to do a particular act does not invade the policy of the law that requires conveyances of title or interest in land to be in writing, for it may amount to nothing more than an excuse for an act which would otherwise be a trespass ; but an easement can not be acquired without a deed, or prescription which implies one. Savage, C. J., in Munford v. Whitney, 15 Wend. 380, after reviewing the authorities, observes, “ they all agree in this, that any permanent interest in the land itself can not be transferred except by writing. Much of the discrepancy may have arisen from the different ideas attached to the word license. If we understand it as Chancellor Kent defines it, it seems to me there can be no difficulty. It is an authority to do a particular act upon another’s land; is founded in personal confidence, and is not assignable. For example, A. agrees with B. that B. may hunt or fish on his, A.’s land; A. thereby gives B. a license for that purpose. This gives B. no interest in the land; he can not authorize any other person to go upon the land; it is a personal privilege granted to B. alone. If after A. has given his consent, and before B. has entered upon his land, A. changes his mind, he has a right to do so and forbid B. from entering upon his land for the specified purpose. The license is thus far executory and may be revoked at pleasure. If B. afterwards enters he is a trespasser. If however B. enters before any revocation of the license, the license is then executed, and it ,is not-competent for A. to revoke it and make B. a trespasser. This doctrine is applicable only to the temporary occupation of land, and confers no right nor interest in the land.”
Though it is difficult, often, to determine between an ease;¡ment and a license, it seems to be settled that the right to ¡enter and remain on another’s land for a certain time or indefinitely at the pleasure of the party claiming the privilege is an interest in the land which can only be ■ created by deed. *121A license can not be countermanded, after it has been executed, so as to permit acts done under it to be treated as trespasses ; and though sometimes it may not be easy to ascertain the point of time at which a parol license may be revoked, when it is no longer executory and the licensee has expended money on the faith of it and is in the enjoyment of the privilege connected with it, yet there must be a time at which it is revocable; otherwise it would create a permanent interest in land. It may be however that when acts have been performed upon the faith of a license, the party giving .it may be equitably estopped from revoking it-to the injury of the other party, but the estoppel will be limited by the injury it is invoked to prevent; as if A. gives B. the privilege of passing over his land, it may be countermanded at any time and no harm will be done, for the parties will stand after the revocation where they were before ; but if the license is that B. may build a house on A.’s land, and B. on the faith of the license erects the house, he might have the right of removing it, and A. would perhaps be denied the power of revocation until B. has been indemnified by the use of the property for the money he had expended on it.
The other judges concurring, the judgment will be reversed and the cause remanded.