By the Court.
Young, J.The general principle of law which underlies this case, is well established. If a man bind, himself, by a positive, express contract, to do an act in itself possible, he must perform his engagement, unless prevented by the act of God, the law, or the other party to the contract. No hardship, no unforeseen hindrance, no difficulty short of absolute impossibility, will excuse him from doing what he has expressly agreed to do. This doctrine may sometimes seem to bear heavily upon contractors; but, in such cases, the hardship is attributable, not to the law, but to the contractor himself, who has improvidently ,assumed an absolute, when he might have undertaken only a qualified liability. The law does no more than enforce the contract as the parties them*504selves have made it. Many cases illustrating the application of the doctrine to every variety of contract, are collected in the note to Cutter vs. Powell, 2 Smith Lead. Cas. 1.
The rule has been applied in several recent cases, closely analagous to the present in their leading facts. In Adams vs. Nichols, 19 Pick. 275, the defendant Nichols contracted to erect a dwelling house for plaintiff on plaintiff’s land. The house was nearly completed, when it was destroyed by accidental fire. It was held that the casualty did not relieve the contractor from his obligation to perform the contract he had deliberately entered into. The court clearly state and illustrate the rule, as laid down in the note to Walton bs. Waterhouse, 2 Wms. Saunders, 422, and add : “ In these and similar cases, which seem hard and oppressive, the law does no more than enforce the exact contract entered into. If there be any hardship, it arises from the indiscretion or want of foresight of the suffering party. It is not the province of the law to relieve persons from the improvidence of their own acts.”
In School Dist. vs. Dauchy, 25 Conn. 530, the defendant contracted to build and complete a school house. When nearly finished, the building was struck by lightning, and consumed by the consequent fire, and the defendant refused to rebuild, although plaintiffs offered to allow him such further time as should be necessary. It was held that this non-performance was not excused by the destruction of the building. The court thus state the rule: “ If a person promise absolutely, without exception or qualification, that a certain thing shall be done by a given time, or that a certain event shall take place, and the thing to be done, pr the event, is neither impossible nor unlawful at the time of the promise, he is bound by his promise, unless the performance, before that time, becomes unlawful.”
School Trustees vs. Bennett, 3 Dutcher, 513, is almost identical, *505in its material facts, with the present case. The contractors agreed to build and complete a' school house, and find all materials therefor, according to specifications annexed to the contract; the building to be located on a lot owned by plaintiff, and designated in the contract. When the building was nearly completed, it was blown down by a sudden and violent gale of wind. The contractors again began to erect tbe building, when it fell, solely on account of the soil on which it stood having become soft and miry, and unable to sustain the weight of the building; although, when the foundations were laid, the soil was so hard as to be penetrated with difficulty by a pickaxe, and its defects were latent. The plaintiff had a verdict for the amount of the instalments, paid under the contract as the work progressed. The verdict was sustained by the supreme court, which held that the loss, although arising solely from a latent defect in the soil, and not from a faulty construction of the building, must fall on the contractor.
In the opinion of the court, the question is fully examined, many cases are cited, and the rule is stated, “ that where a' party by his own contract creates a duty or charge upon himself, he is bound to make it good if he may, notwithstanding any accident by inevitable necessity, because he might have provided against it by his contract. * * * If, before the building is completed or accepted, it is destroyed by fire or other casualty, the loss falls upon the builder; he must rebuild. The thing may be done, and he has contracted to do it. * * * * No matter how harsh and apparently unjust in its operation the rule may occasionally be, it cannot be denied that it has its foundations in good sense and inflexible honesty. He that agrees to do an act, should do it, unless absolutely impossible. He should provide against contingencies in his contract. Where one of two innocent persons must sustain a loss, the law casts it upon him who has agreed to *506sustain it, or rather, the law leaves it where the agreement of the parties has put it. * * * Neither the destruction of the incomplete building by a tornado, nor its falling by a latent softness of tbe soil, which rendered the foundation insecure, necessarily prevented the performance of the contract to build, erect and complete this building for the specified price. It can still be done, for aught that was opened to the jury as a defense, and overruled by the court.”
In Dermott vs. Jones, 2 Wallace, 1, the foundation of the building sank, owing to a latent defect in the soil, and the owner was compelled to take down aud rebuild a portion of the work. The contractor having sued for his pay, it was held that the owner might recoup the damages sustained by his deviation from the contract. The court refer with approval to the cases cited, and say : “ The principle which controlled them rests upon a solid foundation of reason and justice. It regards the sanctity of contracts. It requires a party to do what he has agreed to do. If unexpected impediments lie in the way, and a loss ensue, it leaves the loss where the contract places it. If the parties have made no provision for a dispensation, the rule of law gives none. It does not allow a contract fairly made to be annulled, and it does not permit to be interpolated, what the parties themselves have not stipulated.”
Nothing can be added to the clear and cogent arguments we have quoted, in vindication of the wisdom and justice of the rule, which must govern this case, unless it is in some way distinguishable from the cases cited.
It is argued that the spot on which the building is to be erected, is not designated with precision in the contract, but is left to be selected by tbe owner ; that, under the contract, the right to designate the particular spot being reserved to plaintiffs, they must select one that will sustain the building *507described in the specifications, and if the spot they select is not, in its natural state, suitable, they must make it so; that in this respect the present case differs from School Trustees vs. Bennett.
The contract does not, perhaps, designate the site of the proposed building with absolute certainty; but in this particular it is aided by the pleadings. The complaint states that defendants contracted to erect the proposed building on “a certain piece of land of which the plaintiffs then were and now are the owners in fee, fronting on Minnesota street, between Third and Fourth streets, in the city of St. Paul.” The’ answer expressly admits that the defendants' entered into a contract to erect the building, according to the plans, &c., “ on that certain piece of land in said complaint described,” and that they “ entered upon the performance of said contract, and proceeded with the erection of said building,” &c. This is an express admission that the contract was made with reference to the identical piece of land on which the defendants afterwards attempted to perform it, and leaves no foundation in fact for the defendants’ argument.
It is no defense to the action, that the specifications directed that “ footings ” should be used as the foundation of the building, and that the defendants, in the construction of these footings, as well as in all other particulars, conformed to the specifications. The defendants contracted to “ erect and complete the building.” Whatever was necessary to be done in order to complete the building, they were bound by the contract to do. If the building could not be completed without other- or stronger foundations than the footings specified, they were bound to furnish such other foundations. If the building could not be erected without draining the land, then they must drain the land, “ because they have agreed to do everything necessary to erect and complete the building.” *508(3 Dutcher, 520; and see Bermott vs. Jones, supra, where the same point was made by the contractor, but ruled against him by the court.)
As the draining of the land was, in fact, necessary to the erection and completion of the building, it was a thing to be done, under the contract, by the defendants. The prior parol agreement that plaintiffs should drain the land, related, therefore, to a matter embraced within the terms of the written contract, and was not, as claimed by defendants’ counsel, collateral thereto. It was, accordingly, under the familiar rule, inadmissible in evidence to vary the terms of the written contract, and was properly excluded.
In their second and third offers, the defendants proposed to prove that after the making of the written contract, and when the defendants, in the course of their excavation for the cellar and foundation, first discovered that the soil, being porous and spongy, would not sustain the building, unless drained, the plaintiffs proposed and promised to keep the soil well drained during the construction of the building; that, in consequence, the defendants did not drain the same; that plaintiffs for a time kept the soil drained, but afterwards, and just before the fall of the building, they neglected to drain, in consequence of which neglect the soil became saturated with water, and the building fell; and that a like- promise was made by defendants at the beginning of the erection of the second building, followed by like part performance and neglect, and subsequent, and consequent, fall of the building.
The rule that a sealed contract cannot be varied by a subsequent parol agreement, is of great antiquity, the maxim on which it rests, unumquodque dissolvitur eodem modo, quo ligatur, being one of the most ancient in our law. (Broom Leg. Max. 877 ; 5 Rep. 26 a, citing Bradon, lib. 2, fol. 28 ; and see Bracton, fol. 101.) In early days the rigor with which it was en*509forced in the courts of law, led to the interference of chancery to prevent injustice. (Per Lord Ellesmere, Earl of Oxford’s case, 2 Lead. Cas. in Eq. 508* ; 1 Spence, Eq. Jur. 636.) In later times that rigor has become much relaxed, although the English courts of law have refused to permit sealed contracts to be varied by parol in cases of great hardship. Littler vs. Holland, 3 T. R. 590; Gwynne vs. Davy, 1 Man. & Gr. 857; West vs. Blakeway, 2 Id. 729; and see Albert vs. Grosvenor Investment Co., Law Rep. 3 Q. B. 123.
But in this country, it has become a well settled exception to the rule, that a sealed contract may be modified by a subsequent parol agreement, if the latter has been executed, or has been so acted on that the enforcing of the original contract would be inequitable. Munroe vs. Perkins, 9 Pick. 298 ; Mill-dam Foundry vs. Hovey, 21 Pick. 417 ; Blasdell vs. Souther, 6 Gray, 149; Foster vs. Dawber, 6 Excheq. 854, and note ; Thurston vs. Ludwig, 6 Ohio St. 1; Delacroix vs. Bulkley, 13 Wend. 71; Allen vs. Jaquish, 21 Wend. 628 ; Vicary vs. Moore, 2 Watts, 451; Lawall vs. Rader, 24 Penn. St. 283 ; Carrier vs. Dilworth, 59 Id. 406 ; Richardson vs. Cooper, 25 Me. 450 ; Lawrence vs. Dole, 11 Vt. 549; Patrick vs. Adams, 29 Vt. 376; Siebert vs. Leonard, 17 Minn. 436 ; Very vs. Levy, 13 How. 345; 1 Sm. Lead. Cas. (6th Ed.) 576.
Whether the evidence offered shows a valid consideration for the plaintiff’s promise, or whether it shows that such promise, though without consideration, has been so acted on as to enure*, by way of estoppel or otherwise, to release defendants from their obligation to drain, are questions that were fully discussed at the bar, but which we are not called upon to determine ; for the objection is well taken by counsel for the plaintiffs, that the evidence embraced in the second and third offers is inadmissible under the pleadings.
I n their answer, the defendants allege an offer and promise *510by plaintiffs, (made after the defendants had commenced work under the contract,) to keep the land drained during the erection of the building. No consideration is alleged for this promise, and, as nudum pactum, it could of itself, have no effect to vary the obligations imposed on the defendants by the sealed contract. The answer proceeds to allege “ that the plaintiffs wholly and wrongfully failed and neglected to. drain or cause to be drained the said piece of land, or any part of the same.” It is clear that the defendants would have no right to rely on this naked promise, followed by no acts of plaintiffs in part performance. If the defendants went on with the building, without taking the precaution to drain the land, they proceeded at their own risk. The answer sets up no facts on which an estoppel can be founded, and shows no defence to the action.
But the defendants, at the trial, offered to prove, not only that the plaintiffs offered to drain the land, but also “ that the plaintiffs did, for a time, keep the same drained, * * * * but afterwards they neglected to do so,” &c. Assuming that the facts offered to be proved would constitute a defense, (and we are not prepared to say they would not,) no such defense is pleaded in the answer.
The tendency of this proof was to establish a new defense, not pleaded, and to contradict, rather than sustain, the allegations of the answer. For this reason it was inadmissible, even if the facts offered to be proved would, if admissible, constitute a defense to the action. If the proof offered.would have no such tendency, it was immaterial, and for this reason also was rightly excluded. And as all the evidence embraced in each offer, was offered as a whole, and a part thereof was inadmissible, the entire offers were properly rejected.
The objection that the evidence offered was “ incompetent, irrelevant and immaterial,” was sufficiently specific. The de-*511fondants’ counsel must know the contents of the answer, and that evidence inconsistent therewith is inadmissible, if objected to.
There was, therefore, no error in the exclusion of the evidence offered, and the order appealed from is affirmed.