¶1The principal objection urged by appellant is that the contract was not mutual and will therefore not he specifically enforced. To this conclusion, as a general rule, many authorities can be cited, but the exceptions or apparent exceptions to it are so numerous, and so important, that the decided eases illustrating them now- constitute an almost equal volume of authority. Among those exceptions are optional agreements to sell land at specified price and terms within a fixed time, especially if supported by a good and executed consideration. Upon fundamental principles there seems to be no difficulty in supporting the validity of such agreements. In their ultimate analysis they are but offers to sell, and, if accepted before withdrawal, become binding, because thereupon the other party becomes bound, and a complete contract arises, entirely mutual. Uor, on principle, is there any reason why the seller, for a good consideration, may not bind himself that the offer shall not be withdrawn before a specified date. A so-called time option to purchase con*242tains only the above elements, namely, an offer to sell, accompanied by agreement to hold such offer open. Beach, Mod. Cont. § 886 et seq.; Waterman, Spec. Perf. § 200; Willard v. Tayloe, 8 Wall. 661; Brown v. Slee, 103 U. S. 828; Guyer v. Warren, 175 Ill. 328, 51 N. E. 580; Cheney v. Cook, 7 Wis. 413; Wall v. M., St. P. & S. S. M. R. Co. 86 Wis. 48, 56 N. W. 367. In this case an abundant consideration appears for defendant’s promise to sell to plaintiff for $200 whenever he concluded to sell at all in the fact that thereby he secured conveyance to himself of the property in question; a consideration wholly executed by plaintiff on the faith of defendant’s contract, and which cannot be recalled, nor measured in money, so as to he compensable in damages. In the light of both principle and authority we must hold that the agreement of defendant was a binding one, and that upon its acceptance by plaintiff it became a mutual contract, which ought to be specifically enforced, unless some other considerations should lead the judicial discretion otherwise.
¶2PTo such considerations are suggested, save that the land is now worth $300, instead of $200, as when the contract was made, and that defendant has placed thereon structures of the value of some $1,200. After duly weighing these, however, the trial court, in its discretion, has deemed them insufficient to overcome plaintiff’s equities. In reviewing that decision we can only consider whether an abuse of discretion appears, not whether originally we should have decided in the same manner. We cannot say that any such abuse is apparent. The equities in favor of plaintiff are obvious and cogent. It may well be that the loss of this particular ten acres of land from his entire tract may be seriously detrimental, and that, while the maintenance of sawmill thereon might compensate, its application to agricultural or other uses might be most damaging. On the other hand, the relatively slight appreciation of the value from $200 to $300 in ten years cannot be more than the parties anticipated when the contract was made in 1891, *243and the erection of the additional buildings thereon was defendant’s own act, done in view of his duty to reconvey, and which plaintiff could not prevent Besides this, the judgment in practical effect allows- defendant to remove all such structures by awarding him, upon his election, the sum of $400 in lieu of such privilege.
¶3By the Court. — Judgment affirmed.