What is Comparison Of Handwriting?

Legal Definition
Evidence. It is a general rule that comparison of hands is not admissible; but to this there are some exceptions. In some instances, when the antiquity of the writing makes it impossible for any living witness to swear that he ever saw the party write, comparison of handwriting, with documents known to be in his handwriting, has been admitted. For the general principle, see Skin. 579, 639; 6 Mod. 167; 1 Lord Ray. 39, 40; Holt. 291; 4 T. R. 497; 1 Esp. N. P. C. 14, 351; Peake's Evid. 69; 7 East, R. 282; B. N. P. 236; Anthon's N. P. 98, n.; 8 Price, 653; 11 Mass. R. 309 2 Greenl. R. 33 2 Johns. Cas. 211 1 Esp. 351; 1 Root, 307; Swift's Ev. 29; 1 Whart. Dig 245; 5 Binn. R. 349; Addison's R. 33; 2 M'Cord, 518; 1 Tyler, R. 4 6 Whart. R. 284; 3 Bouv. Inst. n. 3129-30. Vide Diploma.
-- Bouviers Law Dictionary
Legal Definition
A comparison by the juxtaposition of two writings, in order, by such comparison, to ascertain whether both were written by the same person. A method of proof resorted to where the genuineness of a written document is disputed; it consists in comparing the handwriting of the disputed paper with that of another instrument which is proved or admitted to be in the writing of the party sought to be charged, in order to Inter, from their identity or similarity in this respect, that they are the work of the same hand. Johnson v. Insurance Co., 105 Iowa, 273, 75 N. W. 101; Rowt v. Kile, 1 Leigh (Va.) 216; Travis v. Brown, 48 Pa. 9, 82 Am. Dec. 540.
-- Black's Law Dictionary
Legal Definition
The identification of an instrument as genuine by comparing it with a known specimen of the writing of the alleged writer. See 1 Leigh (Va.), 216.
-- Ballentine's Law Dictionary