Base unit of ruling engine by Sir Thomas Merton
Base unit of ruling engine by Sir Thomas Merton, in purpose-made wooden case
Ruling engine by Sir Thomas Merton, including gantry (diamond tool-holder) with Merton nuts at each end and 3 ruled brass cylinders (2 in box), 5 metrological gratings, 2 square gratings, moire' fringe grating and vernier, by Diffraction Gratings and Optics Ltd, stored in the following parts
Base unit of ruling engine by Sir Thomas Merton, in purpose-made wooden case
Gantry (diamond tool holder) from ruling engine by Sir Thomas Merton, with Merton nuts