Plaintiff brought this action to recover a balance claimed to be due him for services performed for the defendant under the following written contract:
"This Agreement, made the 7th day of May, in the year one thousand nine hundred and eighteen by and between Bert D. Keck, architect of Grand Porks, North Dakota, party of the first part, and A. J. Kavanaugh, owner, of Grand Porks, North Dakota, party of the second part.
"The architect agrees to prepare and furnish preliminary sketches, working drawings, necessary details, specifications, draw contracts between owner and contractors and to give general supervision during building operations for a theater, store and apartment building for site 65 x 125 feet, to be erected at Grand Forks, North Dakota, for the owner, for a compensation of five per cent of the total cost of the work. Additional compensation to be charged for residence work, alterations, or special work, as may be agreed upon.
"For all work outside of the town in which the architect lives the owner to pay all necessary traveling and hotel expenses.
"The owner agrees to pay the architect three and one half per cent of the total cost of the work when bids are opened and one and one half per cent when the work is completed.
"If work is postponed or abandoned after the preliminary sketches are made, the owner agrees to pay the architect one and one quarter per cent of the architect’s estimated cost, or three and one half per cent when plans and specifications are entirely complete.
“To be built on DeMers avenue, when owner desires. Plans shall include building complete with seating. Bids to be taken and compensation to architect to be based on lowest bids received on various parts.
*84“Drawings and specifications are instruments of service, and as such, are to remain tfie property of tfie architect.
[Signed] Bert D. Keck,
A. J. Kavanaugh.”
The complaint alleges that the plaintiff pursuant to said contract performed the services specified therein; that the lowest bid upon the work specified in the plans and specifications for the building was the sum of $96,864.75; that bids were received and opened on or.about June 1, 1918; that under the terms of said contract there became due and owing to the plaintiff for the services so performed the sum of $3,372.76; that no part of the same has been paid except $750, and that payment of the balance has been refused.
The answer admits the execution of the contract, but avers that prior to the execution thereof the plaintiff was specifically informed by the defendant that the defendant did not have and could not expend for the proposed building any sum in excess of $60,000; and that the plaintiff must prepare plans and specifications for a building that could be constructed complete for not to exceed said sum; that plaintiff assured and promised defendant that the building so to be provided for in the plans and specifications to be prepared by the plaintiff would not cost more than $60,000 fully completed; that defendant entered into the written contract with this understanding, and in reliance upon said promises and assurances of the plaintiff, and would not have entered into a contract for the preparation of plans and specifications for any building costing' any greater sum than $60,000; that the plans prepared by the plaintiff was not for a building costing $60,000, but for a building costing $96,364.76, according to the lowest bid received for the construction thereof; that the plans and specifications prepared by the plaintiff were valueless to the defendant; that he paid plaintiff $750 before he became aware of the fact that the plans and specifications were not as agreed upon. The defendant therefore demands that the action be dismissed, and that he have judgment against the plaintiff for $750, the amount paid him by the defendant. The plaintiff replied, denying the new matter in the answer. The case was tried to a jury upon the issues thus framed. The jury returned a verdict in favor of the defendant for the amount of his counterclaim. The plain*85tiff Has appealed from the judgment and from the order denying his motion for a new trial.
Plaintiff specifies the following reasons why the judgment should be reversed and a new trial ordered:
(1) That the court erred in permitting the defendant to introduce' testimony to the effect that it was understood and agreed between the parties that the cost of the building for which plans and specifications were to be drawn by the plaintiff was not to exceed $60,000,
(2) That the court erred in refusing to permit the plaintiff to introduce evidence tending to show the actual cost to the defendant of preparing the plans and specifications involved in this action.
(3) That the evidence introduced and submitted to the jury is insufficient to support the verdict.
(4) That the plaintiff was entitled to a new trial, particularly upon the ground of newly discovered evidence.
The questions will be considered in the order stated.
(1) Plaintiff contends that the rights and obligations of the parties were fixed by the written contract, and that the testimony adduced by the defendant to the effect that there was an understanding between the parties that the building plans provided for in the contract should be for a building which might be constructed at a cost of not to exceed' $60,000 was inadmissible on the ground that it tended to contradict and vary the terms of the written contract.
We do not believe that the contention is sound. The rule invoked applies to unambiguous writings which on their face evidence a complete agreement between the parties. In such case, in absence of fraud or mistake, it is conclusively presumed that the whole engagement of' the parties is expressed in the writing, and the parties are precluded' from introducing parol evidence for the purpose of contradicting,varying, or altering, the terms of the writing. Nor may collateral parol agreements which add to or detract from the terms of the writing be shown, if they have the effect of contradicting, varying, or altering the terms thereof. But where the writing shows that it is not a complete statement of the entire transaction, as where it is silent as to' some matter which is essential to a proper understanding and interpretation of the writing; and where the parol evidence is offered to show the existence of an oral agreement entirely consistent with the-*86terms of tbe writing, then tbe rule contended for does not apply. 9 Enc. Ev. 345-351; 10 R. C. L. pp. 1019, 1030-1032. This is recognized both by our statutes and decisions. See Putnam v. Prouty, 24 N. D. 517, 140 N. W. 93, and statutory provisions considered in that case.
It will be noted that the written agreement in this case is entirely silent upon the question of the cost of the building, as well as upon its height and the materials of which it is to be constructed. It would be strange indeed if there was no understanding whatever as to these •matters. The contract might have reference to a two-story frame building to cost $15,000, or it might have reference to a ten-story brick building to cost $500,000 or more. It would be equally applicable in either case. The evidence as to the parol agreement with respect to the cost of the proposed building did not tend to contradict or vary the terms of the written contract. The parol agreement sought to be ' established by such evidence was entirely consistent with tbe terms of tbe writing. The following language used by the supreme court of Kansas in considering a similar question is quite applicable here: “Ilow high shall the building be? How is it to be finished? How much is it to cost ? There must be something outside the contract to determine these questions. The plaintiff must have had instructions outside the contract with which to undertake to comply, in the preparation of his plans. One of those instructions must have been concerning the cost of the building, and the outside agreement or understanding between these parties concerning the cost of the building does not contradict or vary the terms of this contract. Such an understanding merely supplies an omission in the contract, which omission must be supplied before the contract can be complied with.” Bair v. School Dist. 94 Kan. 144, 146 Pac. 347.
(2) It is next contended that the court erred in refusing to permit the plaintiff to show the amount of work done and the number of persons engaged in preparing the plans and specifications. It is contended that that evidence was admissible as bearing upon the probabilities of the case, i. e., whether it was probable that the plaintiff would have agreed to perform the amount of work which he did if the amount of his compensation was to be computed on the basis of a building costing not to exceed $60,000; After a careful consideration we have reached *87the conclusion that the trial court ruled correctly in excluding such evidence. It is true “a contract may he explained by reference to the circumstances under which it was made and the matter to which it relates.” Comp. Laws 1913, § 5907. And even in an action on an express contract for services performed, evidence of the reasonable value of such services is admissible, where there is a dispute as to the compensation fixed by the contract. In such case the evidence is admissible, not as a basis for the amount of recovery, but as bearing upon the probabilities of the case; that is, it is admissible for the reason that it affords the jury a view of the conditions and circumstances existing at the time the contract was made, and hence-may furnish the jury some aid in determining which of the conflicting statements is more likely to be true. Munster v. Stoddard, 44 N. D. 105, 170 N. W. 871. But the evidence offered by the plaintiff did not relate to any fact or condition existing at the time the contract was made. It had reference solely to acts performed by, and wholly within the control of, the plaintiff subsequent to the time the contract was made, — acts over which the defendant had no control, and upon the performance of which no estoppel or admission against his interest could be predicated.
(3) It appears that after the bids had been submitted the plaintiff made certain changes in the plans which had a tendency to decrease the cost of the building and he wrote letters to the various bidders asking them to submit new bids upon the plans as altered. Later he wrote other letters to the different bidders advising them that it would be impossible to go ahead with the work because structural steel could not be obtained for the construction of the proposed building on account of a certain order made by the War Industries Board. The plaintiff offered these various letters in evidence, but they were excluded upon defendant’s objection. Error is assigned on this ruling. Little or no argument is submitted in support of this contention. We are of the opinion that the ruling was correct.
(4) It is next contended that the evidence is insufficient to sustain the verdict. It is conceded that the defendant testified to a state of facts which is in accord with the verdict, but it is contended that the facts and circumstances shown by other evidence in the case is so at variance with the testimony of the defendant that that testimony should not be believed. We are unable to agree with this contention. *88There are certain facts and circumstances which tend to contradict defendant’s testimony, but there are other facts and circumstances which tend to corroborate it. The weight and sufficiency of the evidence were for the jury. It requires an extraordinary case to authorize the court to regard sworn testimony as manifestly impossible or untrue. 10 R. C. L. p. 1008, § 198. No such situation exists in this case. Primarily, the question in this case was whether the arrangement was as testified to by the plaintiff, or as testified to by the defendant. The jury believed the defendant’s version of the matter; and, as we view it, the jury’s finding has substantial support in the evidence.
The question of the sufficiency of the evidence was also submitted to the trial judge, and he refused to disturb the verdict. The following language used by this court in Munster v. Stoddard, supra, is directly applicable here: “The jurors who heard the testimony and saw the witnesses in this case, by their verdict, said they believed the plaintiff’s version of the matters in dispute between the plaintiff and defendant. The trial judge, who also heard the testimony and saw the witnesses, as well as the jurors and attorneys, and was familiar with all the incidents of the trial, by his order denying a new trial, said in effect that he was aware of no justifiable reason for granting a new trial. It is well settled that where there is any substantial evidence to support a verdict, the granting or denial of a new trial on the ground of insufficiency of the evidence rests in the sound judicial discretion of the trial court, and the ruling will not be disturbed unless a clear abuse of discretion is shown.”
(5) It is next contended that the trial court should have granted a new trial on the ground of newly discovered evidence. The proposed newly discovered evidence is set forth in the affidavits of five persons who claim to have submitted bids for the construction of the building, or for the installation of heating and plumbing therein, or for the hardware to be used in constructing the building. These persons claim to have been present at the time the bids were opened and they say that at that time the defendant expressed no surprise by word or act at the amount of the bids; and made no statement whatsoever indicating that he was in any manner disappointed or discouraged by reason of the amount of the bids; and made no statement to the effect that he would have to abandon the project on account of the cost of the work as shown *89by tbe bids received. In addition to this tbe affidavit of one Larson is to tbe effect tbat tbe lowest bids received for tbe construction of tbe building in accordance with tbe plans and specifications was, in bis opinion, too low to afford a reasonable profit to sucb bidders if they bad been awarded tbe contract; tbat tbe preliminary plans and specifications were most complete and showed in great detail tbe work and material requisite in tbe construction of tbe building; tbat it would be impossible to determine or estimate within many thousands of dollars tbe cost of sucb building under tbe conditions existing in tbe summer of 1918, or at any time, until after bids were received from contractors for tbe work, or prices for labor and material obtained from those engaged in tbe business of building and furnishing material.
Tbe affidavit of one Morrow also contains a statement tbat on tbe 18th day of July, 1918, be met tbe defendant in tbe city of Grand Forks and bad a conversation with him in reference to tbe construction of tbe building in question, and tbat in sucb conversation tbe defendant stated tbat, while tbe cost was higher than be and tbe architect bad expected, be was well satisfied with tbe lowest bids received for tbe construction of tbe various parts of tbe building; tbat in bis judgment said bids were reasonable considering tbe character and kind of building which be intended to construct, and tbat be expected to go ahead with tbe construction if able to make tbe necessary arrangements.
Under-our laws a new trial may be granted for “newly discovered evidence material to tbe party making tbe application, which be could not with reasonable diligence have discovered and produced at tbe trial.” Comp. Laws 1918, § 7660. Tbe exercise of reasonable diligence is, therefore, an express requirement of tbe statute. Tbe moving party must show, not only tbat tbe evidence is newly discovered and tbat it is material to him, but also, tbat “be could not with reasonable diligence have discovered and produced” it at tbe trial. In tbis case there is really no showing of diligence whatsoever. Tbe plaintiff, Keck, malees an affidavit to tbe effect tbat be was not advised by these different persons tbat they could or would testify to tbe facts set forth in tbe affidavits until after tbe trial of tbe action, and tbat be did not know sucb evidence could be produced on tbe trial. It appears, however, tbat all of the affiants are residents of, or represent firms resident in, the city of Grand Forks, where tbe building was to be con*90structed, the bids opened, and tbe action tried. Keck was present at tbe time tbe bids were opened, and from tbe evidence adduced by bim upon tbe trial it is manifest that be was fully aware that tbe proposed new witnesses were also present at that time. Yet be offers no reason for bis failure to call these witnesses upon tbe trial, except tbe one already stated.
It is elementary that a motion for a new trial on tbe ground of newly discovered evidence is addressed largely to tbe sound judicial discretion of tbe trial court, and that tbe appellate court will not interfere unless it is shown that such discretion has been abused. McGregor v. Great Northern R. Co. 31 N. D. 471, 492, 154 N. W. 261, Ann. Cas. 1917E, 141. Tbe trial court’s “discretion is to be exercised in determining tbe diligence shown, tbe truth of tbe matters stated, and tbe materiality and probability of tbe effect of them, if believed to be true.” People v. Weber, 149 Cal. 325, 86 Pac. 671; Scanlon v. San Francisco & St. J. R. Co. 128 Cal. 586, 61 Pac. 271; Hayne, New Tr. & App. §§ 87, 89; McGregor v. Great Northern R. Co. supra. In determining tbe question of diligence it is tbe duty of tbe court “to take into consideration tbe particular circumstances of each case, with all its distinct and varying phases and bearings, for tbe purpose of ascertaining what is and what is not diligence, within tbe contemplation of tbe statute; and its conclusion upon tbe point is so peculiarly and exclusively an exercise of discretion, that tbe appellate court will never be justified in interfering therewith unless tbe record discloses a clear abuse of discretion.” 1 Hayne, New Tr. & App. § 92, p. 433; McGregor v. Great Northern R. Co. supra.
We are wholly agreed that tbe trial court did not abuse its discretion in refusing a new trial on the ground of newly discovered evidence.
Tbe judgment and order appealed from must be affirmed. It is so ordered.
Biedzele, Eobinson, and Bronson, JJ., concur.