Parallel rule owned by Capt. Benson
parallel ruleINSTRUMENTS - PARALLEL RULES
Overall: 2 5/8 x 18 x 3/8 in.
Parallel rule; owned by Captain Timothy M. Benson [1839-1890] and probably used during voyages of bark MARTHA DAVIS, 1878-1889; two ungraduated strips of ebony held parallel by two brass hinges; brass knob for adjustment at center of each ebony strip; no maker's mark