This tool consists of a brass 14 inch rule, graduated in 1/16” and reading right to left, set into a slot in a heavy mahogany round dowel. It is marked “C. E. Gibbs / Boston / Mass” in the center. On the left the rule is stamped “Pat. Applied For.” I've been unable to locate a U. S. Patent for this tool, but have located machinist and “mouldmaker” named Charles E. Gibbs who lived in the Charlestown section of Boston from about 1870 through 1875. Perhaps this is the inventor of this simple tool who may have used it in making casting moulds. It is an interesting tool with some research needed to investigate it further. There is a kink and split in the brass rule at about the 1 – 1 ˝ inch mark. Easily Good.
Price - $50.00