A usage or practice of the people, which, by common adoption and acquiescence . and by long and unvarying habit, has become compulsory, and has acquired the force of a law with respect to the place or subject-matter to which it relates. Adams v. Insurance Co., 95 Pa. 355. 40 Am. Rep. 602; Lindsay v. Cusiuiano (C. C.) 12 Fed. 504; Strother v. Lucas, 12 Pet. 445, 9 L. Ed. 1137; Minis v. Nelson (C. C.) 43 Fed. 779: Panaud v. Jones, 1 Cal. 49S; Hursh v. North, 40 Pa. 241. A law not written, established by long usage, and the consent of our ancestors.