Vixje, J.
Defendants claim (1) that' the evidence is too vague, uncertain, and conflicting to establish with the requisite certainty the contract found by the court t'o have been made; (2) that the contract as found by the court is so uncertain and unilateral that it ought not to be enforced by specific performance; (3) that plaintiffs abandoned the contract and have been guilty of laches in, seeking redress; and (4) that it would he inequitable to decree specific performance.
*1761. In view of tbe relation of the parties and the fact that' the contract was oral and entered into more than ten years previous to the trial, it is not a matter of surprise that there should be not only a conflict but also some vagueness in the evidence. A definite contract, however, may be found and satisfactorily established upon conflicting testimony. The facts and circumstances surrounding a transaction may be such as to make certain and satisfactory that which is left vague and doubtful resting upon the oral testimony alone. The contract found by the court is quite a natural and probable one. A well-to-do farmer with more money on hand than he needs agrees to buy a farm for a newly acquired son-in-law, deed it to him when a substantial part' of the purchase money is paid, and give him such time as he may require in which to pay for it. A farm is found; $6,000 is paid for it and the deed taken in the name of the father-in-law. The son-in-law is put' in possession, occupies, tills, and improves the farm for over ten years, pays the taxes on it, and makes payments aggregating over half the original purchase price. We have examined the evidence with care and are satisfied that, taken in connection with the subsequent conduct of the parties, it sustains with the clearness requisite in such cases the findings- of the court as to what the contract was.
2. In the contract found by the court these essentials are definite: the grantor, the grantee, the consideration, and the premises to be conveyed. Only the time of conveyance and the times of payment are not fixed absolutely. But they are sufficiently fixed so that they can be ascertained to a reasonable certainty. While it may be a matter of some difference of judgment as to what constitutes a substantial payment on .a $6,000 purchase, yet that is no more difficult to determine than what' is a reasonable time in which to make a payment. Contracts which fail to provide for time of payment must be paid within a reasonable time, but they are not held void for uncertainty on that account'. Boyington v. Sweeney, 77 *177Wis. 55, 45 N. W. 938; Lawrence v. M., L. S. & W. R. Co. 84 Wis. 427, 54 N. W. 797; 9 Cyc. 611. So, too, the provision as found by the court that the son-in-law should have such time as he required within which to pay for the farm, means that he should pay as he was able. His ability to pay was a fact that could also be ascertained with that degree of certainty required in the enforcement of contracts.
What was said by the court in Inglis v. Fohey, 136 Wis. 28, 33, 116 N. W. 857, applies peculiarly to the present case:
“If, by aid of evidence showing the situation and surroundings of the parties at the time, and their subsequent acts, if any, construing the terms of the writing, the court can with reasonable certainty determine the meaning intended by the parties, the court will not allow the contract to fall, but will construe it' in the light of such evidence and enforce its terms as so construed, if there be no other fatal objections to it.”
That was also an action for specific performance. Perhaps as striking a case as can be found reported showing the definiteness required in a contract in order to entitle it to specific performance* is that of Hannon v. Scanlon, 158 Wis. 357, 148 N. W. 1082. There it was held that an agreement to deed one of two specified forty-acre tracts to each of two children could not be enforced specifically because it did not appear which tract was to be deeded to each child, nor could it be enforced as a contract to convey two undivided forty-acre tracts to both as tenants in common because that was not the agreement. But there were in that case no surrounding facts and circumstances or subsequent conduct of parties to which recourse could be had to make the agreement more definite and certain. The agreement itself was definitely uncertain. While the general rule is that the mutuality of a contract will be determined as of the time it was entered into, there are many exceptions to it. Conditional contracts, such as options to purchase land, that become binding only upon the happening of an event or the exercise of the choice *178granted, fall outside the rule as to mutuality at the time of their execution, yet they may be specifically enforced upon the happening of the event or the exercise of the option within the prescribed time. Wall v. M., St. P. & S. S. M. R. Co. 86 Wis. 48, 56 N. W. 367; Mueller v. Nortmann, 116 Wis. 468, 93 N. W. 538; Sizer v. Clark, 116 Wis. 534, 93 N. W. 539; McCormick v. Stiphany, 57 N. J. Eq. 257, 41 Atl. 840. If there is a mutuality of remedies when the case is ripe for a decree that is sufficient. 7 Modern Am. Law, 24. Here the son-in-law alleges his ability to pay the whole amount due, and under the terms of the contract the father-in-law could sue for damages for a breach of contract to purchase if the son-in-law refused. There are also cases like Howe v. Watson, 179 Mass. 30, 60 N. E. 415, where the time for specific performance does not come till there has been a full performance by the party seeking it. In that case plaintiff agreed to take care of her sister till she died, on condition that she should leave all her property to plaintiff. The latter performed her part of the contract and the sister died intestate leaving both real and personal property. In an action for specific performance it' was held, there being no obligation on the part of the plaintiff to perform, that so far as respects the right of specific performance an actual performance was equal to an obligation to perform. In the case at bar there has been a partial and substantial performance with an offer to perform the balance, and no good reason is perceived why that is not equivalent to an obligation to perform.
But the decision need not be based on the ground that a part performance is equivalent to an obligation to perform, for, liberally construed, the contract itself meets with the requirements entitling it to s]Decific performance. It is definite, mutual, and founded upon a valuable consideration. It is free from fraud or mistake,., and is reasonable in its scope and purpose. These are the essential requisites. Mulligan v. Albertz, 103 Wis. 140, 78 N. W. 1093.
*1793. The claim that the plaintiffs have abandoned the contract or have failed to seasonably seek the aid of a court of equity is not 'well founded. They left the farm upon the request of the father-in-law in order to aid him in settling a domestic difficulty with his wife, and no doubt they delayed action after further payments were refused because he told them he was going to deed the land to the plaintiff Myrtle Dingman without further payments. So he is responsible for both the abandonment of the farm and the delay in bringing the action.
4. We fail to see anything inequitable in decreeing specific performance. So far as appears from the evidence, $6,000 was the value of the farm in 1901 when it was bought. The father-in-law receives that sum with legal interest. It is now claimed to be worth $18,000. The son-in-law was entitled to the benefit of his purchase by complying with its terms. His labor for ten years added greatly to the value of the farm and it is no more than just that he should reap the reward thereof.
By the Court. — Judgment affirmed.