delivered the opinion of the court. It is objected by the defendant in error, that the selection of an umpire by the appraisers appointed by the parties was premature. If the question had not been settled adversely to this objection, I should have thought it entitled to great consideration. It was certainly intended by the parties that the appraisal should be made by the individuals selected by them, if possible, before requiring the interposition of another. They were bound, as I conceive, to make the attempt to agree. Had they done so without first calling in a third person, possibly they might have concurred. The umpire, sitting and acting with them from the beginning, may have prevented their agreement. Had the parties intended that there should be three appraisers at first, and that the judgment of any two of them should be binding, they would have said so in their original contract, and made the selection accordingly. However, the authorities are against the objection, and we are bound to overrule it.
*333It is not a valid objection to the award that one of the appraisers signed it with the umpire. The authority of the appraisers originally appointed by the parties ceased upon their disagreement and selection of an umpire; but the signature of either was a mere nullity. It was still the act of the umpire. The case of Soulsby v. Hodgson, (3 Burr. Rep. 1474,) is in point, and settles the question. But although I concur with the court in that case, in the point decided by them, yet I by no means agree with them in the reason which they assign. I do not think that an umpire has a right to take what advice, or opinion or assessor he pleases.
The provision in the award, that the plaintiff below would be entitled to receive the sum awarded, after he should have filled up the outside paved ways, was intended as a condition. But the arbitrators had no power to impose it. It was simply void. If unperformed, it would not have prevented the recovery of the money. And as it could injure no one, it did not vitiate the award.
The operative part of the award differs, in terms, from the submission. By the contract, the appraisers were to determine the amount of the diminution or increase of the cost of the building caused by the alterations from the original design. The award is that Mr. Butler is entitled to receive the sum of $2385,29 for the increased cost of the building. This was not saying, expressly, that the sum awarded was the actual amount of the increase of the cost caused by the alterations. But as the recital refers correctly to the contract, that raises a presumption that the award was in accordance with the submission. The inference however is not very strong, and is far from amounting to the presumptio juris et de jure which cannot be rebutted. It would not contradict the award to prove that the arbitrators thought that a considerable part of the amount of the increase of the cost caused by the alteration should be set Off against some deficiency in other parts of the work, and that therefore the plaintiff below was not entitled to receive that part of such increase. Indeed it is apparent from the whole case that the umpire so thought, and acted accordingly.
*334It is a general rule, that when the terms of a written instrument denoting the subject matter are equivocal, parol evidence may be admitted to apply them to a particular subject matter. (3 Stark, on Ev. 1021.) There is nothing in the objection that it does not appear from the award that the plaintiff below had notice of the time and place when and where the arbitrators met. A want of such notice may be proved, or it may appear expressly from the award; and then the objection would be fatal. But it does not appear in this case, nor is it to be presumed. The result is that there is not enough on the face of the award to show that it goes beyond the submission ; neither is it sufficiently precise to shut out parol evidence that the umpire went beyond his authority.
The plaintiffs in error contend that the parol evidence to show that the umpire had exceeded his authority was improperly admitted by the court below. I have already stated one reason why I think that such evidence is admissible. The object was to show that the umpire had no jurisdiction, and that therefore his award was null.and void. .The subject matters referred to the appraisers were clearly and distinctly stated in the contract. And no extrinsic evidence as to them was admitted or offered. Clearly such evidence, if offered, would not have been admissible. It is unnecessary to determine whether, if the award had clearly described the matters decided, parol evidence would have been proper to contradict it in that particular. In this case the award was indefinite as to the subjects investigated and determined. If the arbitrators exceeded their authority, and thereby did injustice tp the plaintiff, that is not apparent upon the face of the award, and can be proved by extrinsic evidence only. If that cannot be admitted, the injured party would be remediless. I know of no rule of law that would exclude it. But it is said that a court of law cannot vacate or set aside an award. True, but it is not necessary to annul an alleged award that never had any vitality. An award, if it may be So called, made by persons without authority, is a nullity ; and may be so declared by any court before which an attempt is made to enforce it. Besides, the court for the cor*335rection of errors, when this case was before that tribunal,(a) expressly decided that the evidence in question was competent, and I cannot see why the question was again raised in the subsequent trial in the court below.
It has been contended by the plaintiff in error that Thomas was an incompetent witness, inasmuch as his testimony would go to impeach the award, and because, even if the testimony of an arbitrator was admissible, his was not the best evidence which could have been adduced. It is well settled that the evidence of an arbitrator cannot be received to impeach his own award. But the witness never made the award in question. It was not his, but was made in opposition to his own opinion. After the final disagreement between him and his associate, preceded as it was by the selection of an umpire, his power ceased. He was no longer an arbitrator. Besides, the evidence of arbitrators has often been admitted to show that they did or did not take into consideration any particular subject matter. That would not be an impeachment of the award, within the principle, unless mala fides should be alleged. The other objection to his competency was equally untenable. He had as good opportunities for knowing, and did know, as much of the matter concerning which he testified, as any other man. He testified that he acted as clerk, and kept the account of the items considered and allowed by the appraisers; that the account kept by him was made up, and a balance struck; that the amount was the same for which the appraisement was made, and that at the last meeting which he attended, the other two appraisers agreed upon this sum, and nothing remained to be done but to have the award written and signed.
The witness proved very clearly that the umpire included in the award matters which had not been submitted by the parties. The submission related exclusively to the cost which might be caused by the alteration from the original design. But the umpire made allowances by way of deduction against Mr. Butler for workmanship and materials, alleged to be defec*336tive in those parts of the building which had not been altered from the form, proportion or construction provided by the original plans and specifications, and which had not been in any manner affected by the alterations actually made. These matters had not been referred to him; and the allowance was the more improper, as all except what related to the alterations had been settled and paid for.
But it is said that the good may be separated from the bad, that the amount of the items properly allowable can here be ascertained from the account kept by the witness Thomas, and that such amount should control the recovery. But the answer to that is that there has not been any formal adjudication as to the amount properly allowable under those items. The account contains a mere estimate. Neither party could make use of it by way of charge or discharge. It was not conclusive evidence of the amount due.
It was contended in behalf of the defendants below, that if the award was void, the appointment of the appraisers remained valid, and that the plaintiff had no right to annul the powers conferred upon them, or to call for the selection of others. An appointment originally good, may become void by subsequent events. Had one of the arbitrators, after the selection, and before making the award, become deranged, or interested in the subject matters of the claim, either event would have rendered him incompetent, and virtually annulled his appointment. The agreement between these parties expressly provided that the amount should be settled by impartial appraisers. If either party had selected one known by such party to have formed an opinion favorable to his interest, it would have vitiated the award. The other party would not have been bound by it. In this case the appraisers were doubtless impartial when originally appointed. But they had subsequently formed an opinion, and expressed it in a solemn manner. They would naturally strongly incline to such opinion on any future investigation. They could not be the impartial men to which both parties are entitled. As jurors, they would certainly have been disqualified. The same rule should apply *337to arbitrators; more especially as their award is of more binding effect than the verdict of a jury. The plaintiff was, therefore, under the circumstances, justified in considering the first selection as virtually annulled, and in calling for a new appointment ; and the defendants should have yielded to his request. But the defendants not only refused to make any new appointment, but virtually refused to renew the investigation before the same arbitrators, by insisting that the appraisal already made was valid, and that it should control the extent of the claim. Their agent, at the time appointed by the plaintiff for the proposed new selection, tendered to him the amount which the appraisers had adjudged to him, and expressly avowed that he had nothing further to say on the subject.
If the award was null and void, and the appraisers and umpire had become virtually incompetent to act, the rights of the parties remained the same as if there had been no appointment or appraiser at all. The application made by the plaintiff to the defendants below, to meet and make a new appointment of appraisers on the 10th of May, 1838, was virtually refused, and, as it appears to me, without any sufficient reason. The question then occurs whether the refusal can prevent the recovery by the plaintiff of money justly due to him. It ought not to have that effect. It certainly cannot be seriously contended that a debtor can, by refusing to arbitrate as to the amount due pursuant to a contract, forever prevent his creditor from recovering a just demand. If the appraisal is a condition precedent and is of so rigid and unbending a character that it must be performed before payment can be enforced, a refusal to arbitrate by the corporation would be a perpetual bar. It is well settled that a court of equity cannot compel a specific performance of an agreement to arbitrate. (6 Ves. 818.) If an attempt should be made to recover the value of the work, in any shape, at law or in equity, it could be met with the answer which the defendants now make, that the value of the work cannot be assessed in any manner except that provided by the parties. I conceive, however, that no party can insist upon a condition precedent when its non-performance has been caused by himself. Such *338non-performance would not prevent the vesting of an estate; nor can it prevent the accruing of a right, or its enforcement by an action. It in effect amounts to a waiver. That there may be an effectual waiver by parol, of a condition specified in a written,' or even a sealed, contract, there can be no doubt. (Fleming v. Gilbert, 3 John. Rep. 528, and the cases there cited.) In the principal case, Judge Thompson, in giving the opinion of the court, said, “ It is a sound principle that he who prevents a thing being done, shall not avail himself of the non-performance he has occasioned.” The contract between the parties was substantially that the plaintiff should make such alteration in the form, proportion or construction as described in the specification, as should be authorized by the superintendent or architect, in writing; and that he should deduct from the contract price for any diminution, or receive in addition thereto any increase, of the cost which might be effected by such alteration; and that if he and the superintendent or architect, did not agree upon the amount, that should be determined by impartial appraisers, one to be chosen by each party, or, in case of their disagreement, by an umpire to be chosen by the appraisers. The plaintiff below alleges that such alterations were made pursuant to the required authority; that they increased the cost; that he and the superintendent or architect did not agree upon the amount; that there had been an actual submission to arbitration which had proved ineffectual; that he had subsequently offered to appoint an appraiser on his part, and requested the defendants below to appoint another, which they had refused to do; and that such increase of cost amounts to a specified sum, which he claims to recover. It was proved that alterations such as were referred to in the contract were in fact made, and the amount of the increase of cost, after all proper deductions, was also established. And also the offer to the defendants, and a refusal, in effect, by them, to arbitrate as to such amount. It was contended by the counsel for the defendants, that there was no proof, on the trial, that the alterations had been authorized by the requisite writing. The bill of exceptions states that the plaintiff below gave evidence that the extra work was *339done, and the extra materials were furnished, at the request of the defendants below. The inference certainly is that the request was made in due form. Besides, the corporation admitted that by selecting appraisers, in the first instance, to value the extra work and materials ; and by the neglect to raise the objection on the trial, which, had it been raised, could probably have been removed by producing the required evidence, they had waived the objection; and it is too late to raise it on a writ of error.
The performance of the extra work, pursuant to the contract, gave to the plaintiff a valid claim against the defendants for the increased cost. The amount only was to be settled by arbitration. That was for the mutual benefit of the parties, and might be waived by them. If waived, by both parties, as I think it eventually was, the plaintiff below might sustain his action, in the same manner as if the clause providing for such arbitration had not been inserted in the contract. I do not go any further than that: nor is it necessary that I should do so. I do not mean to say that the mere performance of the work itself, gave the plaintiff a right of action for what it was worth. But I am clear, that as there had been an actual reference which had proved ineffectual, and a subsequent proposal by the plaintiff to refer, and a refusal by the defendants, the right of action has fully attached. (2 Atk. Rep. 585. 2 Bro. Ch. Rep. 336.)
It has also been contended on the part of the plaintiffs in error, that, supposing that the defendant in error had, under the circumstances, a valid claim against them, he could not recover it in an action of debt. The ground of the objection is that the amount was unsettled. There could not well be any other to the form of the action ; as debt can clearly be maintained for the value of work performed under a contract, whether sealed or unsealed, or whether written or verbal. The distinction is between a claim for the actual value of the work, and one where the plaintiff seeks to recóveí Unliquidated special damages for the breach of a contract. The former is a debt, the latter is not, until settled by a judgment. The action *340of debt can, in general, be sustained for money due on a contract, wherever the demand is capable of being readily reduced to a sum certain, upon the predicated statement of facts. It matters not whether every part of the-alleged claim is established on the trial or not; as it is now settled that the plaintiff may, in this form of action, recover less than the sum stated in his declaration to be due. There is nothing stated in the declaration, nor is there any thing in the evidence, to show that the demand of the plaintiff below is incapable df being reduced to a sum certain.
The judgment of the court below must be affirmed, with single costs.
7 mi, 329, S. C.