. . . "The name is also given to the chaff on the stems of ferns. (n.) An incrustation deposit on the inside of a vessel in which water is heated, as a steam boiler. (n.) Gradation; succession of ascending and descending steps and degrees; progressive series; scheme of comparative rank or order; as, a scale of being. (n.) Hence, any layer or leaf of metal or other material, resembling in size and thinnes" . .