Letter in answer, if self explanatory, is admissible by itself. New Hampshire Trust Co. v. Korsmeyer Plumbing & Heating Co., 57 Neb. 784, 78 N.W. 303 (1899).
Memorandum made contemporaneously with the facts therein noted, when supplemented by oath of party who made it, is admissible as independent evidence. Imhoff v. Richards, 48 Neb. 590, 67 N.W. 483 (1896).
Proof of preexistence and search for written evidence is essential to admission of secondary evidence. Samuelson v. Gale Mfg. Co., 1 Neb. Unof. 815, 95 N.W. 809 (1901).