CA. 1790 BRASS DIAGONAL SCALE RULE

This rule was found with a brass Gourdin à Paris dated 1788 level and small sector rule (also for sale on this website). It measures 9 3/4" x 1 1/2" and has designations "1 A 1250" and "1 A 2500". Otherwise it has numerous lines and numbers and is in absolutely pristine condition for its age.