As the plaintiff’ has not attempted to rescind his contract with the defendant, and now declares bis willingness to perform it, we need not consider his prayer for the repayment of any balance that might be found due upon an account. The defendant by his answer denies the receipt of such a note as is described in the bond, but alleges that after the execution of the bond he received from the plaintiff a note for $850, payable on demand within eight years, with interest annually. If the recital of the note’s description in the bond is material, the defendant is estopped in this case to deny that he received such a note. 2 Smith’s L. C. 457; 4 Com. Dig., Estoppel, A, 2; 1 Greenl. Ev., sec. 26; Met. Yelv. 227, n; Trimble v. The State, 4 Blackf. 436; 1 Saund. Pl. & Ev. 42. If it is not material it is equally immaterial whether the plaintiff in fact received a note of that precise description. We think the condition of the bond substantially fixes the amount and the terms of the payment which the plaintiff’ must make to entitle himself to a deed. Buffum v. Buffum, 11 N. H. 457. The defendant can not, by his answer, for the purpose of defeating this suit, show that a different note was given at the time of the execution of the bond, to alter its condition. If the allegations of the answer were susceptible of being regarded as the statement of a subsequent agreement substituted for the original contract in this respect, still in the absence of proof the court could not find in this case that such was the fact. Miles v. Miles, 32 N. H. 147; Busby v. Littlefield, 33 N. H. 85; 3 Greenl. Ev., sec. 288. We need not, therefore, consider the effect of the defendant’s delay to object, or of his repeated acceptance of payments upon such other note, if it were in fact given. The plaintiff has complied with the condition of his bond as to the payment of $450 and the interest. The date of the sixth payment is not material here, for taking either statement as correct, we find that on the 13th day of March, 1855, the plaintiff had paid all the interest then due, and $450 of the principal. Taking the whole condition of the bond together, we think he was required *29only to make suck a payment, to entitle himself to a deed upon the tender of the mortgage. The amount required to be paid was $450 and interest, “ as the same falls due, during all the time until the sum of $450” should “ be paid,” and not until the mortgage should be tendered. And we must deem the subsequent more general language of the bond limited by this precise statement. If the plaintiff had tendered the mortgage on the 13th day of March, 1855, he would have then been entitled to his deed. Ilis delay to make the tender and demand is not shown to have prejudiced the defendant. Indeed the defendant now declares his willingness to execute the deed if the plaintiff will pay the sum remaining due upon the note now held by the defendant; but such payment was not made by the bond a condition of the execution of the deed. The plaintiff must prevail if his tender of the mortgage was sufficient, and we think it was, for the mortgage follows strictly the condition of the bond, which is not showm to have been modified. Perhaps the defendant may find less difficulty than he apprehends, from the form of the condition of the mortgage, even if the note be as he asserts ; Boody v. Davis, 20 N. H. 140; Robertson v. Stark, 15 N. H. 109; Webb v. Stone, 24 N. H. 287; Johns v. Church, 12 Pick. 560; 1 Hill. Mort. 291; Melvin v. Fellows, 33 N. H. 402; 4 Phill. Ev. (C. & H.) 521; but upon this point it is unnecessary to express any opinion. Ve see no reason to grant the plaintiff’s prayer for an extension of the time for payment of the remainder of the note, or for limitation of the interest. The plaintiff might have tendered the mortgage in March, 1855, which, upon the denial of the answer, we must take it he did not do, and in that case he might at once have proceeded to enforce his rights if the defendant refused to execute the deed. Now he is compelled only to pay the amount fixed by the contract, according to its terms. As the plaintiff’s mortgage is filed in court ready to be delivered to the defendant, and will be operative by estoppel, when the title shall have vested in the plaintiff, a decree must be entered in favor of the plaintiff for the specific performance by the defendant of his agreement to execute a deed as set forth in the bond, and for costs.