TY - CHAP DB - Science History Institute DP - Science History Institute M2 - Courtesy of Science History Institute. Rights: Public Domain Mark 1.0 TI - Plate 158: Screw-jack for breaking the iron gratings of a portcullis T2 - Le diverse et artificiose machine del capitano Agostino Ramelli ID - 9019s269z AU - Ramelli, Agostino CY - Paris, France DA - 1588/// YR - 1588 UR - https://digital.sciencehistory.org/works/9019s269z AB - Can be operated by a single person, easily and with little noise. The device depicted here is also illustrated on Plate 157. Mechanics: wrenches. KW - Jackscrews KW - Machinery LA - ER -