Opinion by
Mr. Justice Thompson,This action was brought by appellant to recover damages for Ms land taken by appellee for the right of way of its railroad and for the injury to the water power of his mills in consequence of its construction. The appellee, while contesting the amount of the damages, contended that, when ascertained, they were payable in its capital stock at par, as provided in the agreement made between the parties. By this agreement it is agreed on the part of the appellant as follows, viz.: “ I will release to the company which undertakes to construct such road the right of way of lawful width through my land in Orange township, Columbia county, Pennsylvania. The damages to be assessed when the road is located, and the amount of such damages to be paid in stock in said railroad. Cost of fencing not included in *190damages, provided no damage is done to the buildings, race or water power.” On the former trial the learned trial judge held that this proviso related to the whole agreement and not to the cost of fencing, and if any injury was done to the water power the damages would be in dollars and cents and were payable in cash, but, upon appeal, in reversing, Mr. Justice Green said (143 Pa. 504) : “ In the photographic copy of the paper as in the printed copy the word ‘ cost’ in the final sentence is the beginning of a new and independent sentence disassociated from the one preceding, and it reads: ‘ Cost of fencing not included in damages, provided no damage is done my buildings, race, or water power.’ The clear meaning of these words is that the cost of fencing shall not be included in the damages, if no damage is done to the buildings, race or water power, that is, if no damage is done to the buildings, race or water power no damage is to be allowed for the cost of fencing. This is the natural construction and meaning of the words. But the court below held that the cost of fencing was to be payable in money value and that the words ‘ provided no damage is done to my buildings, race, or water power ’ did not relate to the cost of fencing but did relate to the damages mentioned in the preceding sentence. That sentence is in these words: ‘The damage to be assessed when the road is located and the amount to be paid in stock in railroad.’ What damage ? Manifestly ‘ the damages.’ All the damages resulting from the location and construction of the railroad through plaintiff’s land. This appears by the preceding sentence that “ I will release to the company which undertakes to construct such road, the right of way of lawful width through my land in Orange township, Columbia Co., Pa.” Immediately following is the provision assessing the damages in the sentence above quoted. Certainly the words ‘ the damages,’ in that sentence, mean all the damages. There is no distinction between damages arising from the taking of the land and those which arise from injury to the buildings, race and water power.’ ”
The counsel for appellant, with their ingenuitjr stimulated by a second trial, raise no less than sixty-four assignments of error. They may however be substantially grouped in three classes: (1st) those relating to the measure of damages; (2d) those relating to the agreement; and (3d) those relating to the manner of the payment of damages.
*191The measure of damages is stated in the above opinion to be: “ Under the general law all the disadvantages arising from the location and construction of the road are to be taken into account in estimating the value of the whole property before the road was built, and after it was finished.” The learned trial judge in his charge followed this rule when he said: “ The true and correct rule in estimating damages is the difference in value of the entire property or tract as a whole unaffected, as it was before the railroad was laid upon it. and as it is affected by the railroad after it is finished or completed.” The amount of appellant’s damages clearly rested upon this basis. In his proof one of the witnesses testified, “ that immediately before the construction of the railroad, he considered the market value of the whole property, as a whole, farm and mills, to have a reasonable market value of $12,000, and immediately after the construction of the railroad, as affected by it,” that he would “judge it would not be worth over $8,000, at the outside.”
The appellant himself testified, “ that before the construction of the railroad the market value of the whole property was $12,000 and afterwards $5,000.” While on cross-examination he admitted that upon the former trial he had advanced the latter amount considerably. The amount of the verdict indicates very clearly that the jury applied the rule thus laid down to the proof. In view of the testimony that appellant received from the contractor compensation for delay in the operation of his mills during the construction of the coffer dam, the assignments of error for the rejection of evidence to prove the damage arising from it cannot be sustained. Nor those which relate to the rejection of the evidence of the value of the property at an intermediate time and before the completion of the road, because the measure of damages is as stated and is not a shifting one. The admissions of the deposition of U. S. Lutz, of the testimony of M. Shaffer, of evidence as to the leakage of the old dam, as to the cost of deepening and widening the pool and dam, as to repairs to the dam, and the conversation of appellant in regard to the removal of materials in the coffer dam, assigned as error in the various assignments, were proper, because the deposition of Mr. Lutz was offered to show the location and dimensions of the old and new race, because the testimony of Mr. Shaffer related to the construction of the new dam, in the *192construction of which it was alleged appellant had acquiesced, and its effect upon the water power, because the leakage was some evidence as to the cause of the weakeningof the water power, because the cost of widening and deepening the pool and the dam might be considered by the jury in determining the amount of damages, because the repairs tended to show the condition of the dam before and after the construction of the railroad, and because the conversation of appellant showed that the removals were made with his assent and tended to negative a permanent injury to the water power.
The assignments of error in affirming appellee’s sixth, seventh, eighth, tenth and twelfth points must fail, for the reason that substantially questions of fact were thus submitted to the jury to determine whether the enlargement of the race together with the dam was done with the knowledge and acquiescence of appellant, whether the change had materially affected the capacity of the mills and whether the course of the water under the railroad bridge would be impeded. It is manifest these were questions of fact, and in affirming appellee’s points were properly submitted to the jury.
The amount of damages thus ascertained, the next question involved in this case, relates to the manner of their payment. In the first trial the appellant’s contention was mainly directed to the point that the agreement by reason of the injury to the water power was rescinded and that the appellee had forfeited its rights under it, while that of the appellee, to the payment of damages in stock, except those arising from injury to the water power. Now however, in view of the interpretation placed upon it by this court, they have materially altered their positions. On the one hand appellant denies generally the contract, while on the other the appellee alleges that all the damages are payable in stock. The impeachment of the agreement is pressed upon various grounds. It is contended that there was in fact no agreement made, but merely a proposal, and no notice of its acceptance shown bjr appellee. The appellant, the owner of two mills (saw and grist), and of a fa'rm, was naturally interested in the construction of a railroad in his immediate neighborhood. This is shown by the testimony of Mr. Jamison, who testified that “ he (appellant) always seemed extremely anxious to have the road built and talked a great many times about it, *193and about his light of way with me. He said that the people ought to give the right of way up the valley, and nothing ought to be put in the way to prevent the road being built, and he volunteered to assist in getting rights of way from parties who had not released.” He referred to this agreement and “ frequently talked about his right; was entirely satisfied with it and said that if he was able he would do even more, that he would put in money to build the road if he was able to do it.” “ He made no objection to the contract at that time.” To aid in the accomplishment of this desired object he executed the agreement as a release of the right of way through his lands and not merely as a proposal to be followed by an agreement. Its language clearly establishes this. Its commencement is “I hereby agree; ” this is followed by “I will release to the company the right of way, damages to be assessed when the road is located; ” then by the manner of their payment. Upon its acceptance by the company it became an agreement binding upon both parties. Whitsitt v. Trustees, 110 Ill. 129. The work upon the road was begun during the winter of 1886 and 1887. In September, 1886, the board of directors of appellee passed a resolution reciting “ that the agreements heretofore made and signed by landowners for the right of way along the company’s road be ratified and accepted, except any provisions contained in said agreement for the maintenance of fences in the future, and that in case where stock is to be paid for right of way the president shall cause proper certificates of stock to be executed and issued upon releases made.” Thus the company placed upon its record a general acceptance of all the agreements for rights of way and made provision for the delivery of the stock when the same were to be paid for with it. The present agreement was with one of such landowners for a right of way, “ to be paid for in stock,” was covered by this resolution, and is a substantial acceptance of it. The company began its work upon the right of way through his farm and made considerable expenditures of money. It did so in pursuance of the right of way granted by the agreement, without any objection or dissent on the part of the appellant, and was a clear manifestation to appellant that his contract had been accepted by it. It is plain that such work being done in a substantial performance of the contract, was as well defined a notice of ac*194'ceptance as one clearly expressed in writing, and is sustained by the rule of the common law “ that the fulfillment of that which the promisor stipulates for has always been deemed the best and sufficient proof of assent, and notice need not be given unless the circumstances are such that he cannot inform himself by inquiry: ” Hare on Contracts, 313. Such acceptance was not too late by reason of the delay of over three years. No time was specified in the agreement, and, from the nature of the work to be done, the time required to organize the company, and raise the money necessary for the enterprise, it was not intended that it should in any manner be of the essence of the contract. The purpose of the appellant as shown was to secure the building of the railroad, and as soon as the company was in condition to build, it was contemplated that it should then enter upon the right of way thus granted. No time was designated for acceptance and a reasonable time was intended. Time does not become of the essence of a contract unless so declared or indicated by the circumstances: Shaw v. Turnpike Co., 2 P. & W. 454; Hewson v. Paxson, 38 Leg. Int. 308; Barnard v. Lee, 97 Mass. 92. The delay under the circumstances of this case was not unreasonable, and it does not appear by the evidence that appellant himself so treated or considered it. But it is contended that the damages were assessable upon the location of the road, and that the failure on the part of the appellee to assess them at that time operated as a rescission of the contract. Ordinarily the right to damages arises upon the location of a railroad, and the amount to be recovered may include those caused by the location and the subsequent construction, and is so recoverable in but one action: Wadhams v. Lackawanna and Bloomsburg R. R. Co., 42 Pa. 309; Commonwealth v. Pittsburgh R. R. Co., 101 Pa. 196. This agreement by its terms provides for damages ascertainable upon construction. Mr. Justice Green so holds in his opinion when, in speaking of the damages, he says: “ Manifestly the damages, all resulting from the location and construction of the railroad through plaintiff’s land.” The injury to the water power was not ascertainable until the construction of the railroad, and its extent depended mainly upon the manner of it. The mass of appellant’s testimony related to damages which would not have been ascertainable upon the location, and only became so upon *195the construction of the road. It is plain in the use of the word “ located ” construction was intended to be the time for the assessment of damages. No action was taken for an assessment until May, 1887, when appellant filed his petition for the appointment of viewers. Prior to this he had an interview with the president of appellee’s company when he made a claim for a specified sum for damages, which was refused, and when a proposition was made to appoint appraisers he desired to consult counsel in regard to it. In view of the fact that the amount of damages from their nature could not be ascertained at the time of the location of the road, and also that the agreement related to such as .necessarily would arise from the manner of its construction, it is clear that the word located was not used in the technical sense as a final line duly adopted by the board of directors of appellee, but as a railroad located and constructed upon the land, and therefore there was no such delay in the assessment of damages as would operate as a rescission of the contract, or a forfeiture of the rights of the appellee under the same.
The appellant further contended at the time of the execution of the agreement, it was agreed that the railroad should be constructed on the west side of the creek and that this collateral parol agreement induced its execution; that by reason of the construction on the east side of the creek it was void, and he became therefore entitled to the payment of damages in money. Where a written contract plainly expresses the deliberate intent of the parties, without any uncertainty, and indicates thus the whole engagement, it cannot be contradicted or varied by parol testimony, except in certain well defined instances which are stated by Mr. Justice Paxson in Phillips v. Meily, 106 Pa. 536, to be : “ First, where there was fraud, accident or mistake in the creation of the instrument itself; second, where there has been an attempt to make a fraudulent use of the instrument in violation of a promise or agreement made at the time the instrument was signed, and without which it would not have been executed.” These exceptions, because of the significance of the writing in defining with certainty the engagements of the parties, require, in order to be established, proof of a clear, indubitable and precise character. In Thorne v. Warfflein, 100 Pa. 519, it is said: “ It is not enough that there are parol stip*196ulations contradictory of a written agreement in order to change its legal effect. There must be fraud, accident or mistake, and the evidence of either must be clear, precise and indubitable,” and in Martin v. Berens, 67 Pa. 459, “ the evidence of fraud or mistake ought to be of what occurred at the execution of the agreement, and should be clear, precise and indubitable, otherwise it should be withdrawn from the jury.”
As the proof here was not of this character the learned trial judge properly withdrew it from the jury. The appellant, the only witness upon this subject in his own behalf, testified that when the paper was signed the understanding was the railroad was to be on the west side of the creek. He said: “ I don’t know that the words were put in on this side of the creek but that was the agreement between us. Then he signed it. That was all of the conversation. The agreement was that he was not to come on the east side of the creek.” The object of this proof was to modify the agreement almost to the extent of a substitution of a new one. The west side of the creek where the appellant owned a narrow strip of land of the width as stated of two rods insufficient for the statutory width of the right of way designated in the agreement as “ lawful width ” is in Mount Pleasant township, while the east side of it where the mills, buildings and farms are is in Orange township. The agreement specifically states “through my lands in Orange township ” (that is on the east side), and makes a provision in regard to damage to buildings, race,, or water power which were on the east side. An agreement thus clear, certain and specific should not be permitted to be contradicted or varied, as claimed, upon the uncorroborated testimony of appellant. To hold so would be practically to sweep away written contracts, destroy their value and substitute in lieu of them loose conversations and verbal understandings.
In North and West Branch Railway Co. v. Swank, 105 Pa. 561, it is said: “ Swank was the only witness who testified in support of the alleged ‘ representations or misrepresentations ’ which, if established, change the terms of the written contract, or, as submitted, actually set it aside. His testimony is uncorroborated — the allegation is denied by the other party and some testimony adduced of its untruth. Were the defendant in error in a court of equity, asking that the contract be reformed or *197set aside, by reason of the alleged fraud, and the allegation denied, upon such testimony as adduced here, his bill would be at once dismissed. His testimony could not be considered by the chancellor, unless corroborated by another witness, or the equivalent of another. Unless there be such testimony as a chancellor could consider on a question of this nature, it ought not to be submitted to a jury in a proceeding at law.”
In Pennsylvania Railroad Company v. Shay, 82 Pa. 198, it is said: “ It has been more than once held that it is error to submit a question of fraud to the jury upon slight parol evidence to overturn a written instrument. The evidence of fraud must be clear, precise and indubitable, otherwise it should be withdrawn from the jury.”
In Thorne v. Warfflein, supra, it is said: “We have gone very far in permitting parol contemporaneous evidence to defeat written instruments. To go further would be practically to abrogate the rule. The distinctions are fully and clearly set forth in the opinion of Mr. Justice Williams, in the case "of Martin v. Berens, supra, and as there stated they meet with our approval. He sums up the subject in the following terse and effective words, to which we agree: ‘ Where parties without any fraud or mistake have deliberately put their engagements in writing, the law declares the writing to be not only the best but the only evidence of their agreement, and we are not disposed to relax the rule. It has been found to be a wholesome one, and now that parties are allowed to testify in their own behalf, the necessity of adhering strictly to it is all the more imperative.’ We cannot agree that it is proper to throw the whole case into the jury box on the ground of fraud, simply because one of two parties to a written contract testifies that there were parol stipulations contradictory to the terms of the writing agreed to at the same time.”
While appellant was uncorroborated he was in point of fact contradicted by Mr. Conner, the other person living who was present at the execution of the paper. He testifies positively there was no agreement “ not to come on the east side of the creek.” With the appellant’s testimony uncorroborated and in fact contradicted there was no evidence to be submitted to the jury to vary or contradict the agreement. As it is not impeachable, with its damages assessable after the construction *198of the railroad, as the appellee entered upon the right of way in pursuance of it and performed its part in good faith as required by it and not in the exercise of a right of eminent domain, and as no bad faith has been shown, the group of assignments of error which relate to these subjects are not sustained.
The agreement provides that the damages shall be paid “ in stock in said railroad.” The par value of the stock was $50.00 per share. A subscriber to the stock of a railroad companjr takes it at its par value. A secret agreement, with an agent obtaining the same, to pay less would not be enforceable : Miller v. R. R., 87 Pa. 95. When therefore this agreement provides that the appellant shall take stock in the company for his damages, it clearly means that he is to take it, as others take it, at its par value. A definite and fixed value was thus 'intended, and not a varying one depending upon the changes of the market as to Value.
But it is contended that the damages for injury to the water power were payable in money, because, on the former trial, one of its counsel having made an admission to that effect, the appellee is estopped from denying it. In the former trial the contention in regard to the agreement was to a grea/t extent one of construction. The interpretation of it has been finally determined by this court. An erroneous admission in regard to it by counsel upon a former trial as a matter of law will not estop his client from denying it in a second trial: Hill v. Epley, 81 Pa. 331; Dungan v. Ins. Co., 52 Pa. 253. An equitable estoppel by matter in pais rests upon the basis of refusal to permit a party to assert what his previous conduct had denied, where another had acted on the faith of such denial and altered his condition. The position of the appellant has no such support. During the trial and subsequently he neither accepted nor acted upon it; he was not by reason of it induced to change his position nor was he misled by it. Having fixed his course by his own compass, he continued in it without deviation. It may in fact be said that here the essential elements of estoppel as stated in Eldred v. Hazlett, 33 Pa. 307, are lacking, and therefore this assignment of error cannot be sustained, nor can it be as corroborative of appellant’s testimony, because the admission relative to damages to the water power on the *199east side of the creek was but an expression of an opinion upon the construction of the written agreement, relative to damages to the water power, and was not evidence corroborative of that portion of his testimony relative to his allegation of a parol agreement making it void, if the railroad should be built upon the east side of the creek.
The appellant agreed to receive in payment for his damages stock at par without regard to its market value, and the evidence of such value, as well as to the mortgages placed upon the railroad tending to affect its value, was properly excluded. It may be the stock may not be valuable at the present time, and as a consequence the appellant may suffer a hardship. But having by his contract made the law governing the case, he is alone the cause of it. It is not the first instance where the value of a contract has been miscalculated. As the damages were payable in stock the verdict was directed to be in stock and was rendered accordingly. This is assigned as error because the verdict is unresponsive to the issue and is not enforceable. As counsel, by an agreement, in writing filed, “ that this action be tried without objection to form or substance of plaintiff’s statement • or defendant’s plea, that all matters of legal demand and all matters of defence lawfully admissible under any form of pleading shall be admissible as if formally set forth by declaration or plea,” broadened the issue to all matters in controversy, the verdict is clearly responsive and its performance can be enforced. Under its equity-able powers the court can by the control of its execution enforce it. In the case of Pierce v. Marple, 148 Pa. 69, where the contract was to pay in lime, Chief Justice Paxson said : “We are of the opinion that the evidence referred to should have been received, and if the jury found the plaintiffs were to take their pay in lime such fact should have been found specially and incorporated in the verdict. The court would have then been enabled to control the execution, and if defendants should refuse to pay in lime could permit the execution to go for money.” The verdict is for damages for plaintiff for $5,200, with in terest payable in capital stock of defendant, and is thus for a specific sum to be paid in stock; and if not so paid execution may be issued for the money. It differs essentially from Bruck v. Mausbury, 102 Pa. 35, where a verdict was “ in favor *200of plaintiff for $246, and plaintiff to complete job according to contract, and from Glass v. Blair, 4 Barr, 196, where it was for defendant and the plaintiff to receive back the machine.”
As the assignments of error are not sustained this judgment is affirmed.