after stating the case as above, delivered the opinion of the court.
The appellant having agreed in the charter party “to provide and furnish the vessel a full and complete cargo of coal,” and this contract being unqualified, and being expressed in plain language, the testimony offered has been objected to on the ground that there is no uncertainty in the meaning of the language used, and that the terms of the written contract cannot be varied or changed by parol evidence. The grounds upon which testimony as to usage is admissible in a case of this kind is that such evidence is necessary to place the court in the situation in which the parties were when they contracted, and thus enable it to understand the meaning of their language. Whether such usage be called a “custom,” or by any other name, if it is one of the circumstances surrounding the parties to the transaction, and was presumably in their minds when the contract was -written, then, in contemplation of the law, such usage is written into the contract. But to have that effect there must be no room to doubt the existence of such a custom, and it must be reasonable, certain, consistent with the contract, uniformly acquiesced in, and not contrary to law.
The existence of such a custom as would control the charter party —that is to say, that would be tacitly incorporated in it on the ground that the parties must be presumed to have contracted with reference to it, and to have had it in mind when making the contract, and for that reason be required to conform to it — must be so ancient, uniform, notorious, and reasonable that all parties doing business of this kind at the port of Baltimore are conclusively presumed to have been acquainted with it, and impliedly annex it to *885tlie language and terms of any contract made which is to, be performed at that port. Any usage of such doubtful authority as to be known only to a few has not this character. The witnesses ior the appellant have entirely failed to prove facts essential to make out a custom, in the sense of the law. They are all dealers in coal, and all testify, in substance, that it was the custom at the port of Baltimore that strikes at the mines relieved the charterers, yet none of them knew of a single instance where a charterer had been so relieved. This amounts to nothing more than a self-serving opinion of parties engaged in the coal business that they have certain rights, with no evidence that such right has ever been acknowledged or acquiesced in; while the witnesses for the libelant, of much longer and larger experience and greater opportunities of knowledge respecting charter parties, testify that there is no such usage or custom. It is incredible that a uniform, long established, notorious usage, such as those who make shipments from that port are presumed to have knowledge of, and therefore to be bound by, should exist, if such witnesses as the libelant produced were ignorant of it, and it is only such notorious, reasonable, and well-defined custom that the courts can presume to have been in the minds of the contracting parties, and therefore to prevail over the express words of the contract. Scrutton, Charter Parties, 16; Bliven v. Screw Co., 23 How. 431, 16 L. Ed. 510; The Harbinger (D. C.) 50 Fed. 941, 943.
The only other point in the case is that made in'the sixth and seventh assignments of error, which rest upon the doctrine of the duty of the party to a contract to mitigate, by reasonable diligence, the loss necessarily respiting from the breach. Assuming that this is a case where such a duty was imposed, we are of opinion that the facts proved do not show any fault in the -libelant. The owners of the vessel were not in Baltimore, and before undertaking to make a new charter they were entitled to know the entire situation, and it appears that shortly after the arrival of the schooner, when the charterer refused to provide a cargo, the agents of the vessel did, without unreasonable delay, make all proper efforts to secure another cargo. There had been a sharp decline in freight rates for coal vessels on account of the strike^ and although it is proved that a few small vessels had secured cargoes prior to the 29th March, at somewhat better rates, yet the testimony shows that, about the time this new cargo was arranged for, other vessels of like capacity were chartered at the same or lower rates. Under the conditions then prevailing, a vessel of this tonnage could not probably upon* the instant secure a cargo suitable to her capacity. The broker’s clerk testified “that this was the best business we could get for the Manning,” and the record does not disclose that any better business was offered, or that the defaulting charterer made any effort to assist or procure a cargo upon any better terms, which it might well have done. The judgment of the court bejow is affirmed.