The Court below allowed the jury to give to the Benson agreement such weight, by way of admission, as they thought it deserved. But it cannot operate by way of estoppel here. Estoppels must be mutual, and plaintiffs in error do not claim under the lease or agreement in question, and cannot, therefore, set up any estoppel under it against Lorman. The instrument is not necessarily inconsistent with his private rights, and while, as against Benson and his grantees, he could not impeach the privileges secured by the lease, no one else could question his title by reason of anything in that arrangement.

Judgment must be affirmed with costs.