Diagram of a Linotype Machine, a "line casting" machine used in printing: A) Matrix with 7 teeth on either side of deep notch. B) Casting the slug line of matrices and space bars clamped against the face of the mould wheel. Lever depressors pump plunger, forcing molten metal through the spout and fills the wheel slot and type depressions in matrices. This 'slug' moved to join previously cast type. C) Matrices falling from distributor bar into a magazine. Dated 20th century.