TY - CHAP DB - Science History Institute DP - Science History Institute M2 - Courtesy of Science History Institute. Rights: Public Domain Mark 1.0 TI - Plate 167: Screw-jack for bending or breaking the iron gratings protecting a city wall or canal T2 - Le diverse et artificiose machine del capitano Agostino Ramelli ID - 4f16c3110 AU - Ramelli, Agostino CY - Paris, France DA - 1588/// YR - 1588 UR - https://digital.sciencehistory.org/works/4f16c3110 AB - Can be operated by a single person, easily and with little noise. The device depicted here is also illustrated on Plate 166. Mechanics: hand crank; worm and worm gear; double toggle linkage. KW - Jackscrews KW - Machinery LA - ER -