Even though a promisor is prepared to keep and does keep his promise according to its express terms, he will, nevertheless, violate his contract unless his performance is rendered as a performance of his promise. In a leading case the parties having contracted to buy and sell a cargo of tea on certain terms, afterwards had negotiations which amounted to a rescission of the first contract and the substitution of a new one for the purchase of the cargo on different terms. When the time for performance came the buyer wrongly contended that the first contract was still in force and the seller on learning of this contention refused to deliver the cargo. The court held that he was entitled not only to do so but to sue the buyer for made, shall extend as far east as Oswego. And therefore defendant contends that the obligation to carry coal westward is conditional solely upon the Transportation Company's uncontrollable willingness to run the boats on Lake Ontario. If this be the sound construction of the agreement, the bill must be dismissed, for, under such circumstances, the court would not tie defendant's hands.
"But we cannot accede to these contentions or adopt this construction. The obligation to carry defendant's coal on all west-bound trips, fairly interpreted in the light of the contest and of the relations of the parties out of which the written agreement grew, carries with it the further implied obligation to run the boats in a reasonable manner continuously during the period of navigation on the Great Lakes east-bound to or beyond Oswego and west-bound calling at this port.
"Looking at the agreement in its entirety, we find the circumstances that will suspend the obligation, in whole or in part, of each party, clearly specified, such as strikes, accidents, or the loss of a vessel. It is not the obligation to continue a west-bound voyage from Oswego once begun, but the obligation to continue in the conduct of its business, that is expressly remitted or suspended. Clearly this has reference to the entire future of the three-year period of the contract; it would be unnecessary to abate the obligation to carry in the event that a vessel be destroyed, if the duty to carry from Oswego were subject to the owner's arbitrary right to keep the vessel on Lake Erie. Furthermore, such a construction would place this part of the plaintiff's business completely at the mercy of the shipowner, inasmuch as plaintiff's obligation is absolute except for the specified excuses, to give defendant its cargo on call at the port. A bilateral contract of the nature here in question will not lightly be construed, so as to give one of the parties a virtual option, instead of imposing upon each of them obligations conditioned solely as they may have expressly agreed."
See also M'Intyre v. Belcher, 14 C. B. (N. S.) 654; Turner v. Goldsmith,  1 Q. B. 544; Genet v. Delaware & Hudson Canal Co., 136 N. Y. 508, 32 N. E. 1078, 19 L. R. A. 127; Jac-quin p. Boutard, 89 Hun, 437, 35 N. Y. S. 496, and supra, Sec. 90 damages although the latter had expressed his willingness to take the cargo of tea at the time agreed upon, it being clear that the buyer's intention if he took the tea was to treat it as a performance under the first contract and not to comply with the terms of the contract which actually bound the parties.31 The only possible breach that could be stated in a declaration against the defendant in the case would be not that he refused to take the tea but that he refused to take it under his promise in the original contract.