A tapering ridge found on a spoon, running from the base of the handle to the midpoint on the back of the bowl. Serves as reinforcement and decoration. Spoons featured rat tails from c 1670-1720 and were made in silver and pewter.
An expansion discontinuity in a sand casting, featured as a long, narrow, linear depression, resulting from sand expansion and minor buckling of the mold surface during filling of the mold.