Since there is no exception in the record to any finding of fact by the trial court, that portion of the plaintiff’s assignment of error relating to the sufficiency of the evidence to support the findings does not bring this question before us. Cooperative Exchange v. Scott, 260 N.C. 81, 132 S.E. 2d 161. However, we note that all of the findings of fact made by the trial court have ample *574support in the evidence and, therefore, would be conclusive upon appeal to this Court even if exceptions thereto had been duly entered. Milk Producers Co-op v. Dairy, 255 N.C. 1, 22, 120 S.E. 2d 548.
The defendant’s husband was not her agent by virtue of the marital relationship. Air Conditioning Co. v. Douglass, 241 N.C. 170, 84 S.E. 2d 828. One who seeks to enforce against an alleged principal a contract made by an alleged agent has the burden of proving the existence of the agency and the authority of the agent to bind the principal by such contract. O’Donnell v. Carr, 189 N.C. 77, 126 S.E. 112. Here, there is no evidence of such authority, real or apparent, in the defendant’s husband to contract on her behalf to credit the purchase price of the building materials upon the purchase price of the land. There is no evidence that the husband purported so to contract on behalf of the defendant or that, if he did, she ratified the arrangement or received any benefit therefrom.