Opinion by

That a material alteration of a contract without the consent of the sureties will discharge them is a principle which is not disputed. But the appellant contends that the sureties in this case arc not discharged, because, first, the agreement between him and Deckerhoof on the 26th of September, 1888, is not an alteration of the contract of June 19,1888, for the due performance of which by Deckerhoof they became sureties; and, second, if it was an alteration of that contract it was made by the architect in the proper exercise of the powers conferred upon him by the parties with the knowledge and approval of the sureties. We think the first contention is sound and that the second is not. The agreement of September 26th was in writing, indorsed on the contract of June 19th and signed by the appellant and Deckerhoof. It was their act. It provided for work additional to that called for by the former contract and fixed the compensation to be paid therefor. It was a separate and independent agreement. It did not expressly or by any fail- implication alter the terms of the preceding contract or affect in the slightest degree the rights and duties of the parties thereunder. The sureties were bound for the construction of the building in accordance with the plans and specifications of that contract and there was no attempt or intent to enlarge their obligation by the subsequent agreement between the owner and contractor. It did not change the work for which the sureties were bound, or the price to be paid for it. As there was no ambiguity in this agreement its construction was for the court, and error was committed in allowing the jury to declare it an alteration of the prior contract and a discharge of the sureties. There is nothing in the parol testimony which affords any ground for a construction of the agreement of September 26th at variance with these views. It abundantly sustains our interpretation of that agreement. *380Both, parties to it testified substantially that it was a distinct and independent undertaking. Whether we consider it as it was written or in the light of the testimony offered to explain •and qualify it, the fact remains that it is not an alteration of the contract for the performance of which the sureties were bound. It takes up the work where that contract leaves it, •and calls for the finishing of the back attic for thirty-five dollars. This work was done by the contractor and paid for by the owner, and it is not a subject of contention in this case. If under the first contract Deckerhoof was not required to paint the building, his agreement with the owner afterwards to paint it for a stipulated sum would scarcely be claimed as a modification of that contract or a change of his obligations under it. •Such an agreement would, like the agreement to finish the back attic, stand by itself, having no connection with or effect upon the work to be done or the price to be paid under the first contract.

We think the learned court below erred in refusing to hold that the agreement of September 26th was not an alteration of the contract of June 19th and in admitting testimony to contradict, qualify or explain it. We do not discover other substantial error. The specifications which complain of rulings which constitute the errors pointed out, are sustained and all other specifications are overruled.

Judgment reversed and venire facias de novo awarded.