B68-460 LOT OF THREE ALUMINUM RULE ATTACHMENTS. A Robinson Rule, one of the rarest of the rule attachments. It was offered in the 1914 Sears catalog, but who made it and whether it was patented are not known; clamps onto the rule using a simple round head machine screw (possibly a modern replacement). A G.F. Hall patent, manufactured by Boye and marked patent pending, mounted on a Stanley No. 84 rule. Plus a Robert Campbell patent, marked only with the patent date. Condition overall good. From the collection of Steve Dice. Good 200-400