In an attempt to make sense out of numerous multiples of 19th century sculptures, the author gives methods one can use to determine the chronology of a series of multiples and the purpose of a given model or cast. The author describes the procedures involved in modeling, carving, molding (plaster, gelatin, sand, investment), casting (plaster, clay or terra-cotta, wax, metal), finishing or chasing, patinating, electroplating and electrotyping, enlarging, reducing, pointing, and signing or marking models, molds and casts. Once these procedures are firmly grasped one can approach an existing model or cast, visually analyze it to determine its mode of manufacture, compare its measurements and weight with other models in the same series and come up with a conclusion as to its quality and originality. -- AATA