after stating the facts of the case, delivered the opinion of the court, as follows:

The covenant in the lease giving the right or option to" purchase the premises, was in the nature of a continuing offer .to sell. It was a proposition extending through the period of ten years, and being under seal must be regarded as made upon a sufficient'consideration.,and, therefore, one from which the defendant was not at liberty to recede. When accepted by the complainant by his notice to the defendant, a contract of sale between the parties was completed.* This contract is plain and certain in its terms, and - *565in its nature and in the circumstances attending its execution appears to be free from objection. The price stipulated-for the property was a fair one. At the time its market value was under fifteen thousand dollars, and a greater increase than one-half in value during the period of ten years could not then have been reasonably anticipated.

When a contract is of this character-it is the usual practice of courts of equity to enforce its specific execution upon the application of the party who has complied with its stipulations on his part, or has seasonably and in good faith offered, and continues ready to comply with them. But it is not the invariable practice. This form of relief is not a matter of absolute right to either party; it is a matter resting in the discretion of the court, to be exercised upon a consideration of all the circumstances of each' particular case. The jurisdiction, eajd Lord Erskine,* “is not compulsory upon .the court, buUthe subject of discretion. The question is not what the court must do, but what it may do under [the] circumstances, either exercising the jurisdiction by granting the specific performance or abstaining from it.”

And long previous-to him Lord Hardwicke,,and other eminent equity judges of England had, in a great variety of cases, asserted the same discretionary power of the court. In Joynes v. Statham,† Lord Hardwicke said-: “ The constant doctrine of this court is, that it is in their discretion, whether in such a bill they will decree a specific performance or leave the plaintiff to his remedy at law.” And in Underwood v. Hitchcox‡ the same great judge said, in refusing to enforce a contract: “ The rule of equity in carrying agreements into specific performance is well known, and the court is not obliged to decree every agreement entered into, though for valuable consideration, in strictness of law, it depending, on the circumstances.”

Later jurists, both in England and in the United States, have reiterated the same doctrine. Chancellor Kent, in Seymour *566v. Delaney,* upon an extended review of the authorities oil the subject, declares it to be a settled principle that a specific performance of a contract of sale is not a matter of course, but rests entirely in. the discretion of the court upon a view of all the circumstances; and Chancellor Bates, .of Delaware, in Godwin v. Collins, recently decided, upon a very full consideration of the adjudged cases, says, that a patient examination of the whole course of decisions on this subject has left with him “ no doubt that, as a matter of judicial history, such a discretion has always been exercised in administering this branch of equity jurisprudence.”

It is true the cases cited, in which the discretion of the court is asserted, arose upon contracts in which there existed some inequality or unfairness in the terms, by reason of which injustice would have followed a specific performance. But'the same discretion is exercised where the contract is fair in its terms, if its enforcement, from subsequent events, or even from collateral circumstances, would work hardship or injustice to either of the parties.

In the case of the City of London v. Nash,† the defendant, a lessee, had covenanted to rebuild some houses, but, instead of doing this, he rebuilt only two of them, and repaired the others. On a bill by the city for a specific performance Lord Hardwicke held that the covenant was one which the court could specifically enforce; but said, “ the most material objection for the defendant, and which has weight with me, is that the court is not obliged to decree a specific performance, and will not when it would be a hardship, as it would be hero upon the defendant to oblige him, after having very largely repaired the houses, to pull them down and rebuild them.” In Fame v. Brown,‡ similar hardship, flowing from the specific execution of a contract, was made the ground for refusing the decree prayed. In that case the defendant was the owner of a small estate, devised to him on condition that if he sold it -within twenty-five years one-half of the purchase-money should go to his brother. Having contracted to sell *567the property, and refusing to carry out the contract under the pretence that he was intoxicated at the time, a bill was filed to enforce its specific execution, but Lord Hardwicke is reported to have said that, without regard to the other circumstance, the hardship alone of losing half the purchase-money, if the contract was carried into execution, was sufficient to determine the discretion of the court not to interfere, but to leave the parties to the law.

The discretion which may be exercised in this class of cases is not an arbitrary or capricious one, depending upon the mere pleasure of the court, but one which is controlled by the established doctrines and settled principles of equity. No positive rule can be laid down by which the action of the court can be determined in all cases. In general it may be said that the specific relief will be granted when it is apparent, from a view of all the circumstances of the particular case, that it will subserve the'ends of justice; and that it will be withheld when, from a like view, it appears that it will produce hardship or injustice to either of the parties. It is not sufficient,.as shown by the cases cited, to call forth the equitable interposition of the court, that the legal obligation under the contract to do the specific thing desired may be perfect. It must also appear that the specific enforcement will work no hardship or injustice,- for if that result would follow, the court- will leave the parties to their remedies at law, unless the granting of the specific relief can he accompanied with conditions which will obviate that result. If that result can be thus obviated, a specific performance will generally in such eases be decreed conditionally. It is the advantage of a court of equity, as observed by Lord Redesdale in Davis v. Hone,.* that it can modify the demands of parties according to justice, and where, as in that ease, it' would be inequitable, from a change of circumstances, to enforce-a contract specifically, it may refuse its decree unless the party will consent to a conscientious modification of the contract, or, what would generally amount to the same thing, *568take a decree upon condition of doing or relinquishing certain things to the other party.

In the present case objection is taken to the action of the complainant in offering, in payment of the first instalment stipulated, notes of the United States. It was insisted' by the defendant at the time, and it is contended by his counsel now, that the covenant in the lease required payment for the property to be made in gold. The covenant does not in terms specify gold as the currency in which payment is to be made; but gold, it is said, must have been in the contemplation of the parties, as no other currency, except for small amounts, which could be discharged in silver, was at the time recognized by law as a legal tender for private debts.

Although the contract in this case was not. completed until ,the proposition of the defendant was accepted in April, 1864, after the passage of the act of Congress making notes of the United States a legal tender for private debts, yet as the proposition containing the terms of the contract was previously made, the contract itself must be construed as if it had been then concluded to take effect subsequently.

It is not our intention to express any opinion upon the constitutionality of the provision of the act of Congress, which makes the notes of the United States a legal tender for private debts, nor whether, if constitutional, the provision is to be limited in its application to contracts, made subsequent to the passage of the act.* These questions are the subject of special consideration in other cases, and their solution is not required for the determination of the case before us. In the view we take of the case, it is immaterial whether the constitutionality of the provision be affirmed or denied. The relief which the complainant seeks rests, as already stated, in the sound discretion of the court; and, if granted, it may be accompanied with such conditions as will prevent hardship and insure justice to the defendant. The suit itself is an appeal to the equitable jurisdiction of the *569court, and, in asking what is equitable to himself, the complainant necessarily submits himself to the judgment of the court, to do what it shall adjudge to be equitable to the defendant.

The kind of currency which the complainant offered, is only important in considering the good faith of his conduct. A party does not forfeit his rights to the interposition of a court of equity to enforce a specific performance of a contract, if he seasonably and in good faith offers t.o comply, and continues ready to comply, with its stipulations on his part, although he may err in estimating the extent of his obligation. It is only in courts of law that literal and exact performance is required. The condition of the currency at the time repels any imputation of bad faith in the action of the complainant. The act of Congress had declared the notes of the United States to be a'legal tender for all debts, without, in terms, making any distinction between debts contracted before, and those contracted after its passage. Gold had almost entirely disappeared from circulation. The community at large used the notes of the United States in the discharge of all debts. They constituted, in fact, almost the entire currency of the country in 1864. They were received and paid out by the government; and the validity of the act declaring them a legal tender had been sustained by nearly every State court before which the question had been raised. The defendant, it is true, insisted upon his right to payment in gold, but before the expiration of the period prescribed for the completion of the purchase, he left the city of Washington, and thus cut off the possibility of any other tender than the one made within that period. In the presence of this difficulty, respecting the mode of payment, which could not be obviated, by reason of the absence- of the defendant, the complainant filed his bill, in which he states the question which had arisen between them, and invokes the aid of the court in the matter, offering specifically to perform the contract on his part according to its true intent and meaning, lie thus placed himself promptly and fairly before the court, expressing a willingness to do whatever it should adjudge he *570ought in equity and conscience to do in the execution of the contract.

Nothing further could have been reasonably required of him under the circumstances, even if we should assume that •the act of Congress, making the notes of the United States a legal tender, does not apply to debts created before its passage, or, if applicable to such debts, is, to that extent, unconstitutional arid void.

In the case of Chesterman v. Mann,* it was held by the Court of Chancery of England, that where an underlessee had a covenant for the renewal of his léase, upon paying to his lessor a fair proportion of the fines and expenses to which the lessor might be subjected in obtaining a renewal of his own term from the superior landlord, and of any increased rent upon such renewal, and there was a difference between the pártiosas to the amount to be paid by the underlessee, he might apply for a specific performance of the covenant, and submit to the court the amount to be paid. So here in this case, the complainant applies for a specific performance, and submits the amount to be paid by him to the judgment of the court.

We proceed to consider whether any other circumstances have arisen since the covenant in the lease was made, which renders the enforcement of the contract of sale, subsequently completed between the parties, inequitable. Such circumstances are asserted to have arisen in two particulars; first, in the greatly increased value of the property; and second, in the transfer of a moiety-of the complainant’s original interest to his brother.

It is true, the property has greatly increased in value since April, 1854. Some increase was anticipated- by the parties, for the covenant exacts, in case of the lessee’s election to purchase, the payment of one-half more than its then estimated value. If the actual increase has exceeded the estimate then made, that circumstance furnishes no ground for interference with the arrangement of the parties. The ques*571tion, in sucli cases, always is, was the contract, at the time it was made, a reasonable and fair one? If such were the fact, the parlies are considered as having taken upon themselves the risk of subsequent fluctuations in the value of the property, and such fluctuations are not allowed to prevent its specific enforcement.* Here the contract, as already stated, was, when made, a fair one, and in all its attendant circumstances, free from objection. The rout reserved largely exceeded the rent then paid, and the sum stipulated for the property largely exceeded its then market value.

■ The transfer, by the complainant to his brother, of one-half interest in the lease, assuming now, for the purpose of the argument, that there is, in the record, evidence, which we can notice, of such transfer, in no respect afl’dets the obligation of the defendant, or impairs the right of the complainant to the enforcement of the contract. The brother is no party to the contract, and any partial interest he may have acquired therein, the defendant was not bound to notice. The owners of partial interests in contracts for land, acquired subsequent to their execution, are not necessary parties to hills for their enforcement. The original parties on one side are not to be mixed up in controversies between the parties on the other side, in which they have no concern.

If the entire contract had been assigned to the brother, so that ho had become substituted in the place of the complainant, the case would have been different. In that event, the brother might have filed the bill, and insisted upon being treated as representing the vendee. The general rule is, that the parties to the contract are the only proper parties to the suit for its performance, and, except in the case of an assignment of the entire contract, there must be some special circumstances to authorize a departure from the nilo.

The court, says Chancellor Cottenham, in Tosher v. Small,† “ assumes jurisdiction in cases of specific performance of-*572contracts, because a court of law, giving damages only for the non-performance of the contract, in many cases, does not afford an adequate remedy. But in equity, as well as at law, the contract constitutes the right, and regulates the liabilities of the parties; and the object of both proceedings is to place the party complaining, as nearly as possible, in'the same situation as the defendant had agreed that he should be placed in. It is obvious, that persons, strangers to the contract, and, therefore, neither entitled to the rights nor subject to the liabilities which arise out of it, are as much strangers to a proceeding' to enforce the execution of it as they are to a proceeding to recover damages for the breach of it.” ■

When the complainant has received his deed from the defendant, the brother may claim froni him a conveyance of an interest in the premises, if he have a valid contract for such interest, and enforce such conveyance by suit;'but that is a'matter with which the defendant has no concern.

It seems that the draft of the trust deed, to secure the deferred, payments, sent to the defendant for examination, was prepared for execution by the’complainant alone, and, contained a stipulation that he might, if he should so elect, pay off" the déferred payments at earlier dates than those mentioned in the covenant in the lease; and it is objected to the complainant’s right to a specific performance, that the trust deed was not drawn to be executed jointly by him and his brother, and that it contained this stipulation, A short answer to this objection is found in the fact,.that the parties had disagreed in relation to the payment to be - made, and until the disagreement ceased no deeds were required. It is admitted .that the form of the trust deed was not such a one as the defendant was bound to receive, but as it was sent to him for examination, good faith and fair dealing required him-to indicate-in what particulars it was defective, or with which clauses he was dissatisfied. ' Whether it was the duty of the complainant or defendant to prepare the trust deed, according to the usage prevailing in Washington, is not entirely clear from the' evidence. There is testimony both ways. The *573true rule, independent of any usage on the subject, would seem to be that, the party who is to execute and deliver a deed should prepare it.' It is, however, immaterial for this case, what rule obtains in Washington.' Until the purchase-money was accepted, there was no occasion to prepare any instrument for execution. So long as that was refused the preparation of a trust deed was a work of supererogation. Besides, the execution of the trust deed by the complainant was to be simultaneous with the execution of a conveyance by the defendant. The two were to be concurrent acts; and if the complainant was to prepare one of them, the defendant was to prepare the other, and it is not pretended that the defendant acted in the matter at all.

The objection to the trust deed, founded upon the omission of the name of the complainant’s brother as a co-grantor, does not merit consideration. All that the defendant had to do was to see that he got a trust deed, as security for the deferred payments, from the party to whom he transferred the title.

The defendant states in his testimony that when the lease was executed he objected to the stipulation for a sale of the; premises, and that the defendant told him that it should go for nothing. And it has been argued by counsel that this evidence should control the terms of the covenant. The answer to the position taken is brief and decisive. First, nothing'of the kind is averred in the answer; second, the testimony of the defendant in this particular is distinctly contradicted by that of the complainant, and is inconsistent with the attendant circumstances; and third, the evidence is inadmissible. When parties have reduced their contracts to writing, conversations controlling or changing their stipulations are, in the absence of fraud, no more received in a court of equity than in a court of law.

Upon a full consideration of the positions of the defendant we perceive none which should preclude the complainant from claiming a specific performance of the contract.

The only question remaining is, upon what terms shall the decree be made ? and upon this we have no doubt.

*574The parties, at tito time the proposition to sell, embodied in the covenant of the lease, was made, had reference to the currency then recognized by law as a legal tender, which consisted only of gold and silver coin. It was for a specific number of dollars of that character that the offer to sell was made, and it strikes one at once as inequitable to compel a transfer of the property for notes, worth when tendered in the market only a little more than one-half of the stipulated price. Such a substitution of notes for coin could not have been in the possible expectation of the parties.. Nor is it reasonable to suppose, if it had been, that the covenant would ever have been inserted in the lease without some provision against the substitution. The complainant must, therefore, take his decree upon payment of the stipulated, price in gold and silver coin. Whilst he seeks equity he must do equity.

The decree of the court below will, therefore, be reversed, and the cause remanded with directions to enter a decree for the execution, by the defendant to the complainant, of a conveyance of the premises with warranty, subject to the yearly ground-rent specified in the-covenant in the lease, upon the payment by' the latter of the instalments past due, with legal interest thereon, in gold and silver coin of the United States, and upon the execution of a trust deed of the premises to the defendant as security for the payment of the remaining instalments as they respectively become duo, with legal interest thereon, in like coin; the amounts to be paid and secured to be stated, and the form of the deeds to be settled, by a master; the costs to be paid by the complainant.

concurred in the conclusion as above .announced — that the complainant was entitled to specific performance on payment of the price of the land in gold and silver coin — but expressed their inability to yield their assent to the argument by which, in this case, it was supported.