This line-dividing engine was used to mark divisions on rectilinear scales (such as thermometric and barometric scales). A long wooden rod with a tracing tip is connected to a micrometric screw enclosed in a brass box. The plate to be etched is positioned under the tip. The screw is rotated by means of a handle fitted with an index and graduated scale. The rotation moves the tip forward. The divisions were gradually marked on the plate by shifting the wooden rod sideways a few millimeters at a time. Provenance: Lorraine collections.