RARE "I. ROUTLEDGE ENGINEER" 2 FOLD SLIDE RULE BY I. BUCK NEWGATE

Excellent condition and highly likely ca 1825. Incredible detail with 100s of stamps. Stamped both "I ROUTLEDGE ENGINEER BOLTON" and "J BUCK 6 NEWGATE ST & WATERLOO RD LAMBETH LONDON". Buck and Routledge were contemporaries so without a doubt Routledge commissioned Buck to produce his rule design. Based on the address at 6 Newgate I would surmise this is one on Buck's very earliest offerings. He worked starting in 1821 and moved to 124 Newgate in 1834.

From The Smithsonian website: "This form of slide rule was invented by Joshua Routledge, a seller of iron goods, in 1808 or 1809. He discussed it in the 1813 (4th) edition of Instructions for the Engineer's Improved Sliding Rule...."