The appellants, plaintiffs helow, sued the appellee, defendant, for a breach of contract, by which they agreed with him to construct a railroad from or near the town of Newton, Alabama, to such point in Coffee county, in this State, at or near Elba, as the chief engineer of the Southwestern Alabama Railway Company might designate. One of the terms of the contract provided that the plaintiffs should receive, as part of the consideration for their work and labor, from $25,000 to $27,000 of the subscription bonus, as the equivalent of so much cash. It was fur*530ther stipulated that no liability should attach to the defendant, the other contracting party, by reason of the failure to collect any of the subscription bonus notes, in the event the road was not constructed, so that a train of cars might be run into Elba on or before January 31, 1898,—a condition on which said bonus notes were payable. The evidence is without conflict to show that the road was not so completed within that time. The plaintiffs insist, however, that because of the fact that the terminus of the road was changed so as not to be built ■within the corporate limits of the town of Elba at all, and because the subscription bonus was conditioned upon the building of the road into the corporate limits of said town,.they have the right to tender back the subscription bonus notes received by them, and demand their equivalent in monev. This construction entirely overlooks the fact that time in the completion of the road into Elba, was expressly made of the essence of the contract. The change in .the location of the road from a point within the corporate limits of the town of Elba to some point without, having been made, as was authorized by the contract, after plaintiffs had made default as to the time limit of the contract,—January 31, 1898,—-to-wit, in February, 1898, it is manifest that whatever loss, if any, which resulted from the failure to collect the subscriptions must fall upon the plaintiffs. Tt mav be, and doubtless is true, that no change could have been made as to the terminus in Elba, before it was ascertained that the road could not be completed within the time specified, so as to conclude plaintiffs by reason of the receipt of the subscription bonus. But the evidence shows that their failure to so complete the road was not due to any change contemplated to be made, or which was made, as to the terminus of the road within Elba, and sfich change was not made until after default to complete, within the time limit, into Elba; and there being a failure to complete the road to that point within the time limited, and time being of the essence of the contract by 'express stipulation, in so far as the subscription bonus was concerned, it follows that the contention of the plaintiffs is without merit.—Thornton v. Sheffield, etc. R. R. Co., 84 Ala. 109; 3 Am. & Eng. Encyc. of Law, 915n.
2. It is insisted that the plaintiffs are entitled to recover for extra work beyond that specified in the eon-*531tract. Upon this question the contract provides that “work on company account will be paid for at the rate of 10 per cent, added to actual cost of labor, material, and tools, etc. * * No claim for extra work will be considered except it be made in writing to the resident engineer within one month after said work has been done.” It is said, this clause has no application in view of the fact that such work was done at the special instance and request of the defendant. The clause itself makes no such exception. It provides in language as general as possible, that “no claim will be considered except it be made in writing,” etc. To hold that it only applied to certain kinds of extra work or extra work done voluntarily by the plaintiffs or at the instance of some agent of defendant, would be an interpolation of language not used in the contract. The contract must be treated as made by the parties, regardless of whether its terms seem harsh or imprudent, provided it offends no rule of public policy. By the very terms of the clause we are considering, there was contemplated the performance of work other than that contained in the specifications; it fixed the method by which compensation for such work could be reached, and it also provided that such work would not be paid for unless a claim in writing was made within a specified time to a particular person. The making of the claim in the manner stipulated was a condition precedent to the right of plaintiffs to claim compensation, and as there is nothing in such a condition offensive to public policy, it only remains for the courts to give it force and effect. Under this clause the defendant had the right to know as the work progressed how much the extra work would cost him, and this right existed whether the work was at his instance or voluntarily done by plaintiffs, or otherwise. The cases of Wood v. Fort Payne, 119 U. S. 312, and Meyer v. Berlandi, 53 Minn. 59, cited by appellants, were cases in which there was an alteration in the contract, so that the parties proceeded in disregard of the original contract, and as upon a new agreement. If the parties to this agreement had by mutual consent changed the terms of the contract, or if the plans and specifications had been mutually changed, thereby increasing the cost of the work, the clause would perhaps have no application. It results that the claim for extra compensation cannot be sustained, unless the condition *532precedent was fulfilled.—Badders v. Davis, 88 Ala. 367; Davis v. Badders, 95 Ala. 348.
It is a general rule that there can be no recovery upon an implied agreement, when the proof establishes an express one. There is, however, an exception to this rule in this, that when the express agreement has been fully executed by the complaining party, and no duty remains but the payment of money by the other, a recovery can be had upon the common counts as upon an implied contract. As long as the contract, in other words, is executory, it must be specially declared upon. Jonas v. King, 81 Ala. 285. The appellants cannot recover upon the common counts, because there is shown to be an express contract which they have not fully executed, in so far as a claim for extra compensation is concerned, by reason of the failure to make the claim within the time and in the manner stipulated. It is true, defendant accepted the work as and for a full performance, but such acceptance was under the contract and upon the presumption that the claim for extra work was abandoned rather than that the condition precedent to its validity was waived.—53 Minn. 59, supra.
3. It is further insisted that plaintiffs have only received a part of the compensation due them under the contract, and they now seek to recover the balance, which defendant says he does not owe, on account of certain estimates that were made from time to time by an engineer as to the amount and character of the work done, and which said estimates he claims are final and conclusive upon both parties. It may be conceded as settled law, that the parties to a contract may stipulate that the estimate of the work done and the compensation due under it, to be made by a third party, shall be final and conclusive, and such stipulation is binding in the absence of fraud or bad faith.—Railroad Co. v. March, 114 U. S. 549; Chicago etc. R. R. Co. v. Price, 138 U. S. 185; notes to Church v. Shanklin, 17 L. R. A. 211, 212; Western Assurance Co. v. Hall, 112 Ala. 318. It is equally true that the estimate of the amount due is not binding in the absence of a provision in the contract to that effect.—Schuler v. Eckert, 90 Mich. 165; Memphis, etc. R. R. Co. v. Wilcox, 48 Pa. St. 161; Central Trust Co. v. Louisville, etc. Railway Co., 70 Fed. Rep. 282, The question for decision, there*533fore, is whether or not there exists any such provision in the contract under consideration. Counsel for defendant refer us to tAvo clauses which, taken in connection with the provision requiring the work to he done to the satisfaction of the chief engineer of ' the Southwestern Alabama Railway Company, and the conduct of the parties in relation to the contract, they insist must be so construed as to deprive plaintiffs of the right to question the engineer’s estimates. The first proAddes that monthly estimates shall be made between the 1st and 5th of each month, and shall be paid by the 20th. Without stopping to give a definition of the word estimates, or attempting to state exactly Avhut this clause does mean, it is clear that it does not give to the estimates therein mentioned any conclusive effect AArhat-ever, nor is any particular person designated by it to make the estimates. We do not undertake to say Avhat effect the making of the estimates and their approval by plaintiffs Avould, without more, of themselves have. That question is not before us. The next clause relates to disagreements between the resident engineer and the contractors as to the meaning of the specifications, in which event the clause provides, that the subject in dispute shall be referred to the assistant engineer Avhose decision shall be final. It Avould appear to be the intention of the parties as expressed in this clause, to provide a method by Avhich controversies as to the manner of the execution of the Avork, could be quickly adjusted by reference to an arbiter or umpire.—Welch v. Woodworking Co., 38 Atl. Rep. (N. J.) 824; Denver etc. Raihoay Co., v. Riley, 7 Colo. 494. But it certainly cannot be held to mean, that the engineer can finally decide Avhat compensation should be paid for the work, since that is fixed by the contract, and it is not conceivable hoAV any controversy as to it could arise betAveen the engineers and the contractors. This is a matter with which the engineers had nothing to do, provided the work Avas done in accordance Avith the contract to the satisfaction of the chief engineer. Neither in the clause under consideration nor elsewhere in the contract, is any engineer authorized to determine what avus the classification of the material excavated in the progress of the work, for this bears no relation whatever to the excellence of the work or the manner of its execution. *534The only possible way in which a dispute could arise over these matters would be through estimates as to the classification of the excavated material. But nowhere in the contract is any engineer authorized to make any estimates at all, unless it can be inferred from that clause in the specifications under the head of “Notice to Contractors,” which reads as follows: “The resident engineer shall not forward a final estimate in favor of any contractor until the same has been examined by the contractor who must endorse his acknowledgment that he accepts said estimate as a full return for all the work done,” etc. If we concede that this authorized the resident engineer to make the estimates, it is apparent that instead of being made conclusive none of them had any binding effect, except the final one, and that only when examined by the contractors and they acknowledged in writing upon it that it is accepted in full return for all the work done. The uncontradicted evidence shows that this .was not done. It will be observed that there are three different kinds of engineers mentioned in the contract,—the chief engineer, the assistant engineer in charge, and the resident engineer. To none of them does the contract expressly give the authority to make the estimates mentioned therein. But if we should indulge the presumption or construction that such authority rested with the resident engineer, there is still absent a provision making such estimates final between the parties. The conduct of the parties in relation to the contract, whatever it may have been, can have no weight in its interpretation, since that can only serve as an aid, in, the event the contract contains provisions of an ambiguous nature. Comer v. Bankhead, 70 Ala. 136. It, therefore, follows that the circuit court erred, in refusing to allow proof of the amount of work done under the contract and the classification of the material excavated. For this error the judgment is reversed and the cause remainded.
Reversed and remanded.