delivered the opinion of the court.

(After stating the facts as above.) Appellee’s contention is that it was excused from delivery in January and *430February, 1917, under paragraphs 1 and 6 of the “conditions” to the contract; and that the correspondence relied on as extending the time of delivery, and condoning the delay by appellants in forwarding specifications to appel-lee as provided in paragraph 7 of the “conditions,” was a novation of the contract for which there was no consideration, and therefore not binding on appellee; and apparently the trial court took that view. In order for a contract for the sale of goods to be discharged by implication by a new contract, the intention to discharge must clearly appear from the inconsistency of the terms of the new and the old contract. A mere postponement of performance by the new agreement does not discharge the old contract. The substitution of one agreement for another, and the postponement of the time for delivery, whether on request of one of the parties or by voluntary agreement, are entirely separate and distinct. Such a modification of the contract as to delivery does not amount to its discharge. As said by the court in Bacon v. Cobb, 45 Ill. 47: “It would be strange law, indeed, if the defendants were allowed to say that, inasmuch as you gave us further time in which to perform our contracts, and we did not comply, you have no right to an action against us on our original contract.” 2 Mechem on Sales, sections 807, 1151, and authorities cited and digested in the notes; and Roberts v. Benjamin, 124 U. S. 64, 8 Sup. Ct. 398, 31 L. Ed. 334. Philip Gruner Lumber Co. v. Algonquin Lumber Co., 123 Miss. 157, 85 So. 191, is directly in point. There the time of delivery of the lumber involved had been extended by agreement of the parties; the seller being justified by the terms of the original contract in not making delivery at the time fixed therein. The court held that the old contract was not discharged by the subsequent agreement postponing the time of delivery. Applying these principles to the facts which appellants’ testimony tended to establish, we find that the delivery of the carload of oysters was postponed from time to time by agreement of the parties, evidenced by a great mass of correspondence *431had between the parties, ‘ and also between each oí the parties and Taylor, the merchandise broker in San Francisco, through whom appellee made the original contract, most of which the trial court ruled out, and that finally it was distinctly agreed as shown by appellants’ letter to ap-pellee of June 8, 1918, and the latter’s reply thereto of June 14, 1918, that delivery should be made not later than March 1, 1919, which was not made.

These principles apply with equal force to the stipulation in the contract contained in paragraph 7 of the “conditions” which provided that “specifications” should be furnished appellee by appellants not later than January 1, 1917, and in default thereof it should be optional with appellee as to whether it would carry out the contract. Appellant’s testimony tended to show that this stipulation was complied with by it; but, if it was not, the correspondence between the parties clearly shows that the failure of appellants in that respect was condoned by the appellee. For illustration: In appellee’s letter to appellants of June 22, 1917, it acknowledges the receipt from appellants of shipping instructions for the carload of oysters, and states, “To all of which we will conform,” and in its numerous letters to appellants, offered in evidence, there is not an intimation that it had or intended to take advantage of any failure of appellants to comply with that stipulation.

It is contended on behalf of appellee that the agreement postponing delivery and waiving the time within which specifications were required to be furnished appellee by appellant amounted to a new contract which discharged the old contract, and, there being no consideration for the new contract, appellee was relieved from performance. As we have seen, the changes referred to did not make a new contract of the old. They were merely modifications of the written contract of November 20, 1916, agreed to by both parties. There was only one contract. The original consideration was sufficient under the law to support such modifications; and, if further consideration were needed, *432the mutual promises of the parties constituting the modifications would furnish it.

It follows from this view of the law that the trial court erred in ruling out- the correspondence between the parties, as well as that between the appellants and appellee on the one hand and Taylor, the latter’s broker in San Francisco, on the other, which tended to show such modifications of the contract. Appellee contends that it was excused from delivery under paragraphs 1 and 6 of the “conditions” attached to the contract, because prior to March 1, 1917, the limit of time fixed for delivery in the contract as originally written, at no time did appellee have the required amount of oysters packed to fill appellee’s contract, nor could they be procured in the ordinary course of its business, filling the contracts of its customers “in rotation,” as it claimed it had a right to do; and appellee’s testimony was addressed to justifying its failure to deliver Avithin that time. The fault of that position is that the contract as modified by the correspondence called for delivery by the appellee at any time not later than the postponed date of delivery, March 1, 1919. If delivery is delayed by agreement of the parties, the postponed delivery date simply becomes part of the original contract. The appellants offered testimony to show that the appellee could have delivered the oysters under the contract. The larger part of this evidence was ruled out by the court, Avhich was error.

The measure of damages in this case is the difference in the contract price of the oysters in question and their market price at the postponed date of delivery, March 1, 1919. If delivery is postponed by agreement of the parties, the market value at the time to which delivery is postponed is taken as the criterion. Summers v. Hibbard, 153 Ill. 102, 38 N. E. 899, 46 Am. St. Rep. 872; Crescent City Mfg. Co. v. Slattery, 132 La. 917, 61 So. 870; 24 R. C. L. section 337, p. 73; Covington Mfg. Co. v. Ferguson, 204 Ala. 192, 85 So. 726.

Reversed and remanded.