THAYER, Circuit Judge,
after stating the ease as above, delivered the opinion of the court.
We think that the instruction given by the circuit court, to return a verdict in favor of the defendant, was properly given. The proposal made by the defendant “to carry the mails * * between Galveston and Velasco'’ must be construed as a proposal to carry it between two towns of that name in the state of Texas; and this proposal, when accepted by the government, bound the defendant to *144carry the mail between the places named in his proposal, and not between Galveston and Quintana. It cannot be said, on the state of facts disclosed by this record, that the words “Velasco” and “Quintana” were merely two different names for (he same place, because it was conclusively shown that there was a well-known settlement or town on the east bank of the Brazos river which went by the name of “Velasco,” and another town on the west bank of the same river, about a mile or one-half mile distant, which was known as “Quintana.” Besides, it is conceded by the government that the cost of transporting the mail from Galveston to Quintana would not be the same as the cost of transporting it from Galveston to Valesco, because of the increased expense of ferrying across the Brazos river. It is evident, we think, from the testimony, that the designation of Velasco as one of the termini of the route was due to a mistake on the part of the post-office department. The post office had formerly been located at Velasco, and the fact that it had been moved across the river, to Quintana, was overlooked when proposals to carry the mail were invited, and when the defendant's bid was accepted. The contract,' when executed, was entered into under a mutual mistake of fact; both parties supposing that there was a post office at Velasco, on the east bank of the river, where the mail could be delivered. In view of the well-known fact that the government does not make a practice of letting mail contracts, or establishing mail routes, except between places where there are post offices, the advertisement for proposals to carry the mail between Galveston and Velasco was tantamount to a representation that there was a post office at Velasco. At all events, the defendant was warranted in assuming, as he appears to have done, that such was the case. Moreover, the advertisement indicates very clearly that it was published, and that proposals were invited, on the assumption that a post office was located at Velasco. When the mistake was discovered, and when the government declined to pay an increased compensation for transporting the mail across the river to Quintana, the defendant, we think, was entitled to abandon the contract, as he appears to have done, and by so doing he incurred no liability. The doctrine is well established that a contract will not be enforced when it appears to have been based on the supposed existence of a certain fact which furnished the motive for entering into tin1 agreement, if it subsequently transpires that the assumption on which the contract was based was erroneous. Courts of equity frequently decree the surrender and cancellation of agreements under such circumstances. Thus in Allen v. Hammond, 11 Pet. 63, it appeared that the parties to the suit had entered into an agreement whereby one was to pay the other a large sum by way of commissions for services to be rendered in inducing the Portuguese government to pay a certain claim for the wrongful seizure of a certain ship and cargo. When the agreement was made the Portuguese government had already determined to pay the cla'm, and had notified the United States to that effect, but this fact was unknown to the contracting parties. Inasmuch as it appeared evident to the court that the agreement *145would not have been made if the last-mentioned fact had been known to the contracting parties, it was decreed that the contract in question should be canceled and annulled. Bee, also, Hitchcock v. Giddings, 4 Price, 135; Scruggs v. Driver’s Ex’rs, 31 Ala. 274, 289; Ketchum v. Catlin, 21 Vt. 191; Gibson v. Pelkie, 37 Mich. 380; Rogers v. Walsh, 12 Neb. 28, 10 N. W. 467; Harrell v. De Normandie, 26 Tex. 120; Bish. Cont. § 587. The judgment; below ivas for tlie right part}’, and it is hereby affirmed.