A 19th-century bone-ivory and electrum folding 'Routledge'-pattern rule, stamped G. COOPER MAKER 5 CHAPEL ST SALFORD the hinge engraver J. Cowder, engraved and stamped with numerous scales including tables for squares cylinders globes and steel coal and stone, also stamped I. Routledge, Engineer, Bolton, with single slider, 24in. (61cm.) long (unfolded)