B-623 ROUTLEDGE ENGINEER'S RULE. Invented in 1811 and described by Phil Stanley as "probably the most elaborately marked and graduated boxwood rules ever made." A two-fold, two-foot rule with a brass slide and with extensive tables used to perform common engineering calculations of the nineteenth century. Crisp and straight, with all its pins, a couple of small stains. Unsigned.Good+ 100-200 NOTE: Absentee bidding ends 5:00pm EST on Friday, March 29, 2019. Live auction is at Camp Hill Radisson, 9:00am, March 30, 2019, Camp Hill, PA.